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University of Iowa Iowa Research Online Theses and Dissertations Summer 2012 Age-related social, emotional, and behavioral differences in children and adolescents manifesting the symptom presentation of nonverbal learning disabilities Joyce Elberta Goins University of Iowa Copyright 2012 Joyce Elberta Goins This dissertation is available at Iowa Research Online: http://ir.uiowa.edu/etd/3300 Recommended Citation Goins, Joyce Elberta. "Age-related social, emotional, and behavioral differences in children and adolescents manifesting the symptom presentation of nonverbal learning disabilities." PhD (Doctor of Philosophy) thesis, University of Iowa, 2012. http://ir.uiowa.edu/etd/3300. Follow this and additional works at: http://ir.uiowa.edu/etd Part of the Educational Psychology Commons AGE-RELATED SOCIAL, EMOTIONAL, AND BEHAVIORAL DIFFERENCES IN CHILDREN AND ADOLESCENTS MANIFESTING THE SYMPTOM PRESENTATION OF NONVERBAL LEARNING DISABILITIES by Joyce Elberta Goins An Abstract Of a thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in Psychological and Quantitative Foundations (Counseling Psychology) in the Graduate College of The University of Iowa July 2012 Thesis Supervisors: Professor William M. Liu Clinical Psychologist Tammy Wilgenbusch 1 ABSTRACT Investigations regarding age-related behavioral, emotional, and social differences between younger and older groups of children with NLD remain scarce (Ozols & Rourke, 1988; Casey, Rourke, and Picard, 1991; Pelletier, Ahmad & Rourke, 2001) and have shown mixed results regarding the direction and severity of internalized and externalized behaviors. The current study explored the behavioral, emotional, and social differences between two groups of children and adolescents. The “younger” group consisted of children between the ages of 6 and 10 years of age. The “older” group consisted of children and adolescents between the ages of 11 and 16 years. Seventy two patient charts were selected for this study (males = 41, females = 31). A one factor Multivariate Analysis of Variance was run to investigate externalized and internalized age-related differences between the two groups. No age-related differences were found indicating that younger and older children may manifest the behavioral, emotional, and social characteristics of NLD in a similar manner. Additionally, results indicated that more than half of the total sample had a comorbid diagnosis of Attention Deficit Hyperactivity Disorder. However, results did not suggest that children and adolescents with NLD are at an increased risk for internalized psychopathology. When the NLD group was compared to a pediatric sample, it was found that the NLD group was more likely to demonstrate explosive behaviors, anxiety, and self-esteem problems. Although no significant agerelated differences were found in the current study, the investigation has implications for practice as information from this study may aid clinicians in making an earlier diagnosis of NLD in children and adolescents, as well as lead to better interventions. 2 Abstract Approved: _______________________________________________________ Thesis Supervisor _______________________________________________________ Title and Department _______________________________________________________ Date _______________________________________________________ Thesis Supervisor _______________________________________________________ Title and Department _______________________________________________________ Date AGE-RELATED SOCIAL, EMOTIONAL, AND BEHAVIORAL DIFFERENCES IN CHILDREN AND ADOLESCENTS MANIFESTING THE SYMPTOM PRESENTATION OF NONVERBAL LEARNING DISABILITIES by Joyce Elberta Goins A thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in Psychological and Quantitative Foundations (Counseling Psychology) in the Graduate College of The University of Iowa July 2012 Thesis Supervisors: Professor William M. Liu Clinical Psychologist Tammy Wilgenbusch Copyright by JOYCE ELBERTA GOINS 2012 All Rights Reserved Graduate College The University of Iowa Iowa City, Iowa CERTIFICATE OF APPROVAL __________________________ PH.D. THESIS _____________ This is to certify that the Ph.D. thesis of Joyce Elberta Goins has been approved by the Examining Committee for the thesis requirement for the Doctor of Philosophy degree in Psychological and Quantitative Foundations (Counseling Psychology) at the July 2012 graduation Thesis Committee: __________________________________ William Ming Liu, Thesis Supervisor __________________________________ Tammy Wilgenbusch, Thesis Supervisor __________________________________ Megan Foley-Nicpon __________________________________ Kathryn Gerken __________________________________ Timothy Ansley To My Parents and Grandmother, Eunice Lockhart ii If one advances confidently in the direction of his dreams, and endeavors to live the life which he had imagined, he will meet with a success unexpected in common hours. Henry David Thoreau, Walden iii ACKNOWLEDGMENTS This project owes its completion to the faith, support, and guidance of many individuals. First, I would like to thank my advisor, Dr. William Ming Liu. Without your persistent support and encouragement, I would have given up on this dream a long time ago. Thanks for believing in me, even when I didn’t believe in myself. I would also like to thank my thesis committee members: Dr. Tammy Wilgenbusch, Dr. Megan Foley-Nicpon, Dr. Kathryn Gerken, and Dr. Timothy Ansley. Thank you for taking time to provide feedback and having patience with me on this long and challenging journey. Much appreciation also goes to Dr. Sheila Barron for assisting me with my data analysis. I appreciate you working with me over the winter break. Most importantly, I would like to thank my family: Ted Goins Sr., Joyce Goins, Ted Goins Jr., and Kimberly Goins. Thank you for all of the love, support, and prayers. I love you all. iv TABLE OF CONTENTS LIST OF TABLES ..……………………………………………………………………..vii CHAPTER I INTRODUCTION………………………………………………………...1 Early Terminology for Learning Disabilities……………………………...2 History of the Definition of Nonverbal Learning Disabilities ……………3 Controversy and Criticism of NLD ……………………………………… 4 NLD, AS, and ADHD ………………………………………………...…. 6 Etiology ………………………………………………………………….. 7 Nonverbal Learning Disability and Subtypes ……….………………..…. 8 Purpose of the Study …………………………………………………….11 Definitions …………………………………………………………...…..12 CHAPTER II LITERATURE REVIEW ……………………………………………….14 Organization of the Literature Review ….……………………………….14 Principle Identifying Features of NLD ……………………………….…14 Past Validity Studies on Rourke’s NLD Model ……………………...….15 Nonverbal Learning Disability and Social Skills ………………………..23 Nonverbal Learning Disability, Internalized Psychopathology, and Age…………………………………………………………………..27 Purpose of Study ………………………………………………………...38 Research Questions …………………………………………………...…39 CHAPTER III METHODOLOGY ……………………………………………………..40 Participants ………………………………………………………………40 Measures ………………………………………………………………...40 Wechsler Intelligence Scale for Children, Fourth Edition ……....41 Judgment of Line Orientation Test.…………………………..….42 Grooved Pegboard Test ……………………………………….....45 Boston Naming Test …………………………………………….46 Bender Visual Motor Gestalt Test …………………………...….46 Word Fluency Test ………………………………………...…….48 Delis Kaplan Executive Function System ……………………….49 NEPSY-II …………………………………………………….….50 Dependent Variables……………………………………………………52 Pediatric Behavior Scale – Parent Version….………………...…52 Procedures ……………………………………………………………….54 Data Analysis …………………………………………………………....55 Supplemental Research Question………………………………………..57 v CHAPTER IV RESULTS ……………………………………………………………...58 Demographic Data………………………………………………………58 Question One …...…………………………………………………….…59 Question Two…...………………………………………………….……60 Question Three….…………………………………………………….…62 Question Four……………………..………………………………….....62 Supplemental Research Question …..………………………………..….64 CHAPTER V DISCUSSION ………………………………………………………..….68 Strength and Limitations ……………………………………….…….….72 Implications for Practice ………………………………………………...73 Implications for Future Research ………………………………………..75 Conclusion ……………………………………………………….……...77 APPENDIX A ROURKE’S NLD MODEL ……………….……………………….......79 APPENDIX B NLD CLASSIFICATION CRITERIA …………..………....…………..81 APPENDIX C CLASSIFICATION RULES FOR NLD ……………………………….83 APPENDIX D PEDIATRIC BEHAVIOR SCALE FACTORS …………………..……85 APPENDIX E PEDIATRIC BEHAVIOR SCALE …………………………………….87 REFERENCES …………………………………………………………………….……92 vi LIST OF TABLES Table 1. Mean T Scores for Each Age Group for Externalizing Behaviors …………..….60 2. Mean T Scores for Each Age Group for Internalizing Behaviors ……………....61 3. Mean T Scores for the Inappropriate Social Behavior Scale and the Perseveration Scale………………………………………………………………63 4. Percentages of Comorbid Psychiatric Diagnoses in the Total NLD Sample.…....64 5. Descriptive Statistics (Raw Scores) and t scores for PBS Subscales by Group (NLD and Lindgren and Koeppl’s (1987) Normative Sample) …………………65 vii 1 CHAPTER I INTRODUCTION Nonverbal Learning Disability (NLD) is a theorized subtype of learning disabilities that presents significant social challenges for those children which it affects. Despite having a robust vocabulary and average to above average intelligence, children with NLD have a difficult time with pragmatic (day-to-day) language, which affects their ability to communicate effectively with others. Deficits in social perception, social judgment and social interaction skills also interfere with the child’s ability to form and maintain friendships. Moreover, children with NLD have been shown to exhibit increased rates of psychopathology (Casey, Rourke, & Picard, 1991). Rourke reported that 10 percent of children with learning disabilities have NLD (Rourke, 1995). This statistic suggests that approximately 1 percent of the general population of the United States currently have NLD. However, it is difficult to know for sure as there is no set criterion for this learning disability. As theorized, the principal assets in NLD are: advanced verbal skills, excellent rote memory, strong auditory retention, and advanced single word reading skills. The principal areas of dysfunction in NLD are: poor visual-spatial and sensory functioning, significant impairment of social interactions, deficits in information processing and organizational skills, and poor motor coordination. Rourke (1995) hypothesized that the combination of these assets and deficits is what ultimately leads children and adolescents with NLD to experience academic and social problems, and internalized psychopathology (e.g. anxiety and depression). 2 Nonverbal Learning Disabilities, like many other learning disabilities, occur in children with average to above average intelligence. It appears to be developmental in nature, but has also been seen in persons suffering from a wide variety of neurological diseases and disorders (Rourke & Fuerst, 1996). For example, Panos, Porter, Panos, Gaines, and Erdberg (2001) evaluated the case of an 11 year old boy with congenital agenesis of the corpus callosum. Results from a comprehensive neuropsychological assessment found that the boy manifested many of the deficits outlined in Rourke’s NLD model. Early Terminology for Learning Disabilities Coming up with terms which properly and adequately reflect disturbances in learning and adjustment as a result of brain dysfunction proved challenging for early researchers. One of the early terms used to designate children with neurological learning and adjustment problems was “brain damage”. However, this term was viewed as inappropriate as it seemed stigmatizing for both the child and the child’s parents. Additionally, the term is misleading because dysfunctions in the brain causing learning disabilities are not necessarily due to damage. Eventually, the term “minimal” was added. The use of this term, minimal brain damage, arose in an attempt to distinguish between children whose involvement was minimal as compared with diffuse. However, how much brain damage constitutes minimal and how much constitutes diffuse is open to opinion (Johnson and Myklebust, 1967). The term “perceptually handicapped” was an outgrowth of Strauss’ work which stressed the importance of perceptual disturbances. Similar to the Strauss Syndrome, it is not the initial observations that are in question but rather it is their application. However, 3 this term is problematic as well, because to infer that all children with neurological learning abilities have perceptual disturbances is misguided. Often the effect is not on perception, rather on symbolic processes or on conceptualization (Johnson and Myklebust, 1967). The diagnostic concept of Learning Disabilities gained momentum during the 1960s and 1970s. The term, LD, was much less stigmatizing. Parents and teachers were more comfortable with the term than the etiologically based labels mentioned above (Lyon, Fletcher, & Barnes, 2003). History of the Definition of Nonverbal Learning Disabilities Johnson and Myklebust (1967) were among the early researchers to describe Nonverbal Learning Disabilities. According to Johnson and Myklebust (1967), children with NLD are unable to comprehend the significance of many aspects of their environment. They cannot “pretend and anticipate” and fail to learn and appreciate the implications of actions such as “gestures, facial expressions, and caresses, as well as other manifestations of attitude” (Johnson & Myklebust, 1967, p. 272). Additionally, they stated that it is the experience itself that is distorted, not the ability to use spoken language or to read and write. And despite having verbal intelligence that is at or above the average level, the child with NLD is unable to acquire the ability to determine the significance of basic nonverbal aspects of daily living. Johnson & Myklebust (1967) further described these children as wanting to engage and play with their peers; however, as a result of their neuropsychological deficits, they have a difficult time doing so due to their inability to comprehend the social world around them. Johnson and Myklebust (1967) found that these children most frequently had 20- to 30-point discrepancies 4 between verbal and performance abilities on tests of intellectual functioning, the nonverbal score being lower. The next major advances in research and thinking about NLD were made by Byron Rourke and his many colleagues. Rourke is the leading exponent of the dominant model and/or definition of NLD today (Davis and Broitman, 2011). Rourke (1995) characterized NLD via neuropsychological assets and deficits that are causative and sequential in nature. Rourke (1995) illustrated his model using the terms “primary,” “secondary,” and “tertiary” because one set of assets/deficits is believed to lead to or cause another set of assets/deficits. Primary neuropsychological assets include: auditory perception, simple motor skills, and memory for rote material. Secondary assets include auditory attention and verbal attention. Tertiary assets include auditory memory and verbal memory. Primary neuropsychological deficits include deficits in tactile perception, visual perception, complex psychomotor skills, and the ability to process novel/new material. Secondary deficits include difficulties in tactile attention, visual attention, and exploratory behavior. Tertiary deficits include tactile memory, visual memory, concept formation, and problem solving. The concepts and dynamics of Rourke’s (1995) NLD model are outlined in Appendix A. Controversy and Criticism of NLD Within the field of psychology, there have been disagreements about the validity of an NLD diagnosis. For example, Pennington (2009) argued that NLD is not even a syndrome. He stated that the defining symptoms of NLD do not co-occur distinctly enough to justify calling NLD a syndrome. He also emphasized that a child with a large verbal IQ > nonverbal IQ disparity does not necessarily have a disorder, even if his or her 5 spatial skills are significantly below the mean. Pennington (2009) further stated there is wide variation in spatial skills in the general population, and not all apparent spatial deficits cause functional impairment. Thus, unless a child’s spatial deficit is associated with functional impairment in academic or social skills, no disorder is present. Another reason for disagreement is that NLD is almost indistinguishable neuropsychologically from Asperger’s Syndrome (AS). Similar to children with NLD, children with AS experience severe and sustained impairment in social interaction (APA, 2000). Particular difficulties are present in nonverbal behaviors (e.g. eye contact, facial expression, and body gestures), peer relationships, and with social reciprocity (APA, 2000). Children with NLD and AS both desire social connection, but have a difficult time forming and keeping friendships. Neuropsychologically, both groups may suffer executive function impairment, although the degree of impairment may be different (Forrest, 2004). In their investigation, Klin, Volkmar, Sparrow, Ciccheti, and Rourke, (1995) found that children with AS show strong verbal skills, poor visual-spatial ability, and problems with executive functioning. Despite possessing excellent vocabularies, there is a delay in the social use of language with both groups. Thus, their communication patterns may include a pedantic style, both in choice of words and in tone of voice (Stein, 2004). Typically, they do not alter speech expressions. And both groups rely on language-mediated interaction relative to nonverbal interaction. Children with NLD and AS may present with other psychiatric disorders, particularly in adolescence, the most common of which being anxiety and depression (Stein, 2004). Symptoms of Attention Deficit Hyperactivity Disorder are commonly seen in both groups. 6 Additionally, these children are at risk for academic problems, and both groups present with a history of motor problems (Stewart, 2002). Forrest (2004) suggested that with careful psychological screening, clinicians can identify the characteristics that differentiate these syndromes. For example, children with AS may present with stereotyped and restricted patterns of interest. They may also demonstrate the need to adhere to routines. Children with NLD do not demonstrate these behaviors. Autistic Disorder shares many of the same features as AS, hence these disorders are often compared to each other. The majority of children with autism score below average on tests of psychomotor intelligence, but 20-30% of these children achieve full scale intelligence quotient scores greater than 70 (Klin, 2000). These children are classified as having high functioning autism (HFA). Children with HFA share many features with children with NLD and AS. Children with HFA also have difficulties with pragmatic language. As in AS, their conversational style is one-sided and in high volume; while meaningful, it is perseverative and unusual in content. Other common features between children with HFA and both AS and NLD include strong verbal and auditory memory and word reading. Shared weaknesses include difficulties with social interaction, complex reasoning, and in both the use and comprehension of nonverbal communication (Rourke, Ahmad, Collins, Hayman-Abello, Hayman-Abello, & Warriner, 2002). NLD, AS, and ADHD As mentioned above, symptoms of ADHD are commonly observed in children with NLD and AS. This finding is not unusual in that many children with learning 7 disabilities in general have problems with attention. However, ADHD can be a comorbid condition in children with NLD, but it cannot be diagnosed in a child with AS (APA, 2000). Although attention problems are common in children with NLD, Stewart (2002) argues that it is often misdiagnosed. She stated that a deficit in attention only describes the overt problem with which the child is struggling. What is special and problematic about NLD is not the same as what is at issue with ADHD. Along the same lines in regards to children with NLD, Rourke (2000) suggested that deficits in visual perceptual skills may be related to attentional difficulty seen in these children rather than a true diagnosis of ADHD. Thus, further research is needed. Etiology The etiology of NLD has not been well-defined. It has been hypothesized that NLD is the result of genetics. The presentation of NLD symptoms have been seen in children with various genetic disorders. Pennington (2009) made a strong case for Turner’s syndrome and Fragile X syndrome (FXS) as presenting with the classic symptoms of NLD. Individuals with Turner’s syndrome have low nonverbal IQs and problems with a variety of visual-spatial tasks. Girls with FXS exhibit deficits in executive functions, worse problems in math than in reading and spelling, intact structural language but impaired pragmatic language, and social anxiety. Another explanation for NLD has been dysfunction of the right hemisphere (Semrud-Clikeman & Hynd, 1990). Given that the right hemisphere is responsible for visual-spatial ability, intermodal integration, and adapting to novel situations, researchers (including Johnson & Myklebust, 1967) have theorized that a dysfunctional right hemisphere is associated 8 with the presentation of NLD symptoms. On a similar note, Rourke (1995) proposed that dysfunction of white matter tracts caused symptom presentation of NLD. White matter connections are required for intermodal integration, for which the right hemisphere is specialized. Lastly, dysfunction in the frontal lobe may also lead to NLD symptom presentation (Stewart, 2002). One of the roles of the frontal lobe is to develop and then supervise the connections between pieces of information stored elsewhere in the brain. The frontal lobe also enables individuals to learn from new information. Individuals with NLD tend to have a difficult time adapting to new situations. Nonverbal Learning Disability and Subtypes Many researchers have questioned the utility of how NLD is classified. There is only one term, NLD, to describe a group of children with quite different nonverbal deficits. This broad categorization may leave some children at a disadvantage when it comes to diagnosis, treatment, and intervention. Some theorists have suggested that, as with many developmental disorders, NLD should be considered as a disorder with different subtypes (Forrest, 2004; Davis & Broitman, 2007). Forrest (2004) proposed a two-subtype model in which children with NLD would be divided into two categories: a visual-spatial deficits category and a social processing disorder category. The visual-spatial disability would include children with visual-spatial deficits so severe as to affect academic performance in subjects such as math. The social processing disorder category would include children whose social skills deficits are primary and cause impairment in daily life functions. Forrest (2004) conceded that both groups may have difficulties with other cognitive abilities such as executive functions, 9 but the emphasis for purposes of diagnosis, treatment, and intervention would be on the area of greatest functional impairment. Palombo (2006) also proposed a subtype model of NLD with four subtypes. Interestingly, Palombo (2006) does not incorporate any academic issues into his model. Rather, his model is based on patterns of social impairment, as they are associated in the three domains of nonlinguistic perception, attention and executive function, and social function. Unlike Rourke (1995) and Forrest (2004), he hypothesized that there are subtypes of NLD who suffer from additional problems of social relatedness and reciprocity that are not related to visual-spatial issues. The first subtype Palombo (2006) described, NLD subtype I, would include children who demonstrate an inability to process complex and nonlinguistic perceptual tasks as their primary core neuropsychological deficits. Only children with these deficits who also develop concomitant social problems are included in this subtype and given a diagnosis of NLD. The second subtype, NLD subtype II, would include children who meet the criteria for inclusion in NLD subtype I and have neuropsychological deficits in the areas of attention and executive function. The third subtype, NLD subtype III, would include children who meet the criteria for NLD subtype I and have social cognition impairments that manifest in reciprocal social interactions, social communication, and affective processing. Lastly, NLD subtype IV would include children who meet the criteria for NLD subtype II and have the same social cognition impairments as those described in subtype III (Palombo, 2006). More recently, Davis and Broitmen (2011) proposed a four-subtype model of NLD. They stated that they believe that all children who present with NLD have 10 significant visual-spatial and executive function difficulties. Thus, they considered these deficits to be the primary components of NLD. These deficits constituted their first and core subtype. Children in this subtype may also have mild social and academic deficits. Their second subtype included children with visual-spatial and executive function difficulties that significantly impact their social functioning. The third subtype is characterized by children with significant visual-spatial and executive functioning difficulties and functionally impacted academic programs. The academic programs are primarily math related but they can also affect advanced reading comprehension, written expression, geography, and the math-related sciences. Their final subtype is characterized by children with visual-spatial, executive function, social difficulties, and academic deficits where all areas are functionally impaired (Davis & Broitman, 2011). Thus, much uncertainty and disagreement remain surrounding a “formal” NLD diagnosis. Although various researchers have speculated on its etiology, little is still known about the possible genetic or environmental cause of NLD. Disagreements still abound on an official definition of NLD. To date, it is not listed in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSMIV-TR, APA, 2000). Nor, is it listed in the International Statistical Classification of Diseases and Health Related Problems, Tenth Revision, World Health Organization (ICD-10; WHO, 2004). As a result, no official set of diagnostic criteria exists, which is problematic, especially in terms of research. In addition to not having set diagnostic criteria, NLD is almost indistinguishable from AS, which further complicates the clinical picture. 11 Purpose of the Study Successful social interchanges require being able to adapt to novel situations and possessing good communication skills, such as being capable of initiating a conversation. In addition, being aware of another person’s affective state and being able to empathize with them are qualities that also aid in successful social interchange. Unfortunately, children and adolescents with NLD exhibit difficulty in many of these areas. They tend to have difficulty adapting to novel and complex situations. Despite having an advanced vocabulary, they have difficulty with pragmatic language, which makes communicating with others more challenging. For some children and adolescents with NLD, reading another person’s facial expressions and body gestures is difficult. As a result they have trouble being aware of another person’s affective state. The combination of these social deficits can lead to failed social interchanges, which has the potential to lead to internalized and externalized psychopathology. Because social interactions play such an important role in a child’s development, it is important to study how NLD effects children’s social interactions. Since NLD is a developmental disorder, it is important to study its effects at different stages of development. Investigations regarding age-related social differences between children and adolescents with NLD remain scarce (Ozols & Rourke, 1988; Casey, et al., 1991; Pelletier, Ahmad & Rourke, 2001) and have shown mixed results regarding the direction and severity of internalized and externalized behaviors. Between 1991 and 2001, little research was published investigating age-related differences in children and adolescents with NLD. Furthermore, the studies that were published regarding learning disabilities did not break their samples into subtypes. Thus, the following study is an exploratory 12 investigation of the age-related social and emotional behaviors of children and adolescents with NLD. The following research questions guided this study. 1. What are the age-related behavioral (e.g. conduct problems, delinquent behavior, aggression) differences between the “younger” group of children (ages 6-10) and the “older” group of children (ages 11-16) diagnosed with NLD? 2. What internalized emotional problems do children and adolescents with NLD display and do these behaviors differ by age group? 3. What social problems do children and adolescents with NLD experience, and do these problems differ by age group? 4. What psychological disorders commonly occur with NLD, and do these differ by age group? In investigating these questions, various databases were searched. The author searched online databases which included PsycINFO and EBSCOhost. These online databases lead the author to various journals, book chapters, and books on Nonverbal Learning Disability. Lastly, the author searched the Mental Measurements Yearbooks to gain information on the psychometric properties of various assessment instruments included in the study. Definitions The following terms/variables are used throughout this study: learning disability/learning disorder and syndrome. 13 Learning Disorders As stated in the DSM-IV-TR, Learning Disorders are characterized by academic functioning that is substantially below that expected given the person’s chronological age, measured intelligence, and age appropriate education (APA, 2000). Syndrome As stated in the DSM-IV-TR, the term syndrome refers to a grouping of signs and symptoms, based on their frequent co-occurrence that may suggest a common underlying pathogenesis, course, familial pattern, or treatment selection (APA, 2000). 14 CHAPTER II LITERATURE REVIEW Organization of the Literature Review This chapter begins with a description of the principle identifying features of NLD using Rourke’s (1989, 1995) NLD model as a reference. Next, empirical studies are reviewed that both support and contradict the validity and utility of Rourke’s (1989, 1995) NLD model. Following this review is an overview of the social aspects of NLD. Lastly, the relationship between NLD, internalized psychopathology, and age are reviewed. Principle Identifying Features of NLD In his first book, Nonverbal Learning Disabilities: The Syndrome and the Model, Rourke (1989) described the characteristics of his NLD model. According to this model, individuals with NLD exhibit outstanding problems in visual-perception, tactile perception, complex psychomotor skills, and novel material. Deficits in visual perception involve impaired discrimination and recognition of visual detail and visual relationships, as well as deficiencies in visual-spatial-organizational abilities. Deficits in tactile perception pertain to difficulties understanding how things feel. Deficits in complex psychomotor skills refer to how individuals move their muscles in a coordinated manner. Lastly, difficulty with novel material involves experiencing difficulties in new situations. Conversely, individuals with NLD demonstrate strengths with simple motor skills, auditory perception, and rote material. Simple motor skills include noncomplex, repetitive motoric skills. Auditory perception involves remembering information that is 15 heard. Rote material refers to material that is overlearned as a result of repetition and/or consistent stimulus input. Past Validity Studies on Rourke’s NLD Model Since publishing his first book, numerous researchers, including Rourke himself, have conducted investigations in an attempt to validate his NLD model and/or discriminate the features of NLD from other disorders. Harnadek and Rourke (1994) conducted a research study to derive a constellation of features that would be most useful for identifying children who exhibit NLD. They divided their participants into three groups: an NLD group (n = 29), a Reading-Spelling (R-S) group (n = 29), and a nonclinical (NC) group (n = 29). The NLD group exhibited outstanding problems in visual-spatial–organizational, tactile-perceptual, psychomotor, and nonverbal problemsolving skills. The NLD group exhibited clear strengths in psycholinguistic skills, such as rote verbal learning, amount of verbal output and verbal classification. The R-S group exhibited relatively poor psycholinguistic skills in conjunction with very well developed abilities in visual-spatial-organizational, tactile perceptual, psychomotor and nonverbal problem solving areas. They also exhibited poor reading and spelling skills but significantly better, though still impaired mechanical arithmetic competence. The nonclinical group did not have any previous documented learning disabilities or formal psychological diagnoses. All of the NC sample and the majority of the R-S group (males = 26) consisted of males. The NLD cases were more equally divided into males and females. Harnadek and Rourke (1994) stated five specific hypotheses: (a) The NLD group was expected to perform worse, and thus be distinguishable from the NC group on tests 16 sensitive to those skills that have been found to be deficient in children with the NLD syndrome (e.g. visual-perceptual-organizational, psychomotor, tactile-perceptual, mechanical arithmetic, and conceptual problem solving); (b) Children within the R-S group were expected to exhibit age-appropriate development of these skills and abilities (with the exception of mechanical arithmetic); in addition they were expected to be distinguishable from the NLD group by their relatively better performance on tests within the aforementioned realms; (c) The NLD group was expected to perform better than the R-S group on measures of some verbal and psycholinguistic abilities that are thought to develop in an age-appropriate manner in individuals who exhibit NLD, but not in children in the R-S group; (d) It was expected that the performances of the NLD group and NC groups would not be distinguishable on certain verbal and psycholinguistic measures; (e) It was expected that those dimensions thought to be primary in the NLD syndrome (i.e. deficits in visual-spatial-organizational, tactile-perceptual, and complex psychomotor skills) would be the principal variables that distinguished the NLD group from the R-S and NC groups. The principle finding of this study was that a subset of four neuropsychological tests: the Target Test (Reitan, 1966), the Trail Making Test, Part B (Reitan & Davison, 1974), the Tactual Performance Test (TPT; Reitan & Davison, 1974), and the Grooved Pegboard Test (GPT; Klove, 1963) served to discriminate the NLD subjects from the R-S and NC subjects with a high degree of accuracy (> 95%). Two tests, the Reading subtest of the Wide Range Achievement Test (WRAT; Jastak & Jastak, 1965) and the SpeechSounds Perception test (SSPT; Reitan & Davison, 1974), best discriminated the R-S children from the NLD and NC children. Compared to the R-S and NC groups, the NLD 17 group performed more poorly on tests of visual-perceptual-organizational skills, psychomotor coordination, complex tactile-perceptual skills, and conceptual and problem solving skills. In addition, the NLD group’s level of performance were within the normal range and did not significantly differ from those of the NC group on tests of the more rote aspects of verbal and psycholinguistic skill. These findings correspond to the pattern of neuropsychological and academic assets and deficits that has been described for the NLD model (Rourke, 1989, 1995). The R-S group performed more poorly than did the NLD and NC groups on the test of rote verbal and psycholinguistic abilities, single-word reading, and spelling skills employed. Unlike the NLD group, however, the R-S children performed in an age-appropriate manner on tests of visual-perceptual-organizational skills, psychomotor coordination, tactile-perception, memory for tactile information, and concept-formation and problem-solving abilities. Finally, the R-S group’s performance fell below age expectation on two psycholinguistic tests: the SSPT and the Auditory Closure Test, (Kass, 1964), and these children performed worse than the NLD group on all verbal and psycholinguistic tests of verbal fluency. In summary, these findings lend confirmatory support to Rourke’s NLD model. Of the neuropsychological features of NLD described by Rourke (1989), deficits in visual-perceptual-organizational, psychomotor coordination and complex tactileperceptual skills appeared to be the most representative, and most discriminating factors of the NLD syndrome in the children that were examined. These are also the dimensions that are described as primary in his NLD model. More recently, Forrest (2004) conducted an investigation in which she evaluated the usefulness of math, internalized psychopathology, and visual-spatial deficits to 18 identify children with NLD. According to Rourke’s model (1989, 1995), children with NLD experience difficulty in mechanical arithmetic, are at risk for the development of internalized psychopathology, and experience primary visual-spatial deficits. Thirtythree children (males = 21, females = 12) participated in this study. The children were placed into three groups: an NLD group (n = 13), a Verbal Learning Disorders (VLD) group (n = 10), and a control group (n = 10). All participants were between the ages of 6 and 10. Of particular note was the way Forrest (2004) determined inclusion for the NLD group. In order to be included in the NLD group, participants had to have a 12-point discrepancy between a higher VC and the lower PO on the Wechsler Intelligence Scale for Children, Third Edition (WISC-III; Wechsler, 1991). The opposite criterion was required for inclusion in the VLD comparison group. An 8 point or smaller difference between the Verbal Comprehension (VC) and Perceptual Organization (PO) scores was required for inclusion in the control group. Either an 8-point difference on the WRAT between the arithmetic and reading standard scores, a diagnosis of NLD, or slowed psychomotor speed as measures by the GPT was also used as criterion for inclusion in the NLD group. Results indicated that the criteria employed by Rourke (1995) to identify children with NLD may not adequately differentiate them. The children with NLD performed as well on math applications as children with VLD and the controls. This study revealed that children with NLD can demonstrate good math abilities when performing certain types of math tasks, especially those that draw on their strong verbal skills. Based on Forrest’s results, a lack of deficit in math should not exclude a child from being identified 19 as exhibiting the NLD syndrome. These results should be interpreted with caution as her sample size was small. In addition, children with NLD were rated by their parents as exhibiting no greater levels of internalized psychopathology than children with VLD or controls. According to Rourke’s model (1989, 1995), children with NLD have increased rates of psychopathology. There was one significant finding in regards to the NLD group’s visual-spatial abilities. Forrest used select subtests from The Developmental Test of Neuropsychological Assessment (NEPSY; Korkman, Kirk, & Kemp, 1997) to evaluate visual-spatial abilities. There was a main effect for group for the Block Construction score, F (2, 32) = 4.4, p = .02. This finding suggested that children with NLD may have specific visual or perceptual impairments, specifically locating objects in space that distinguish them from the other two groups. Qualitative analysis revealed that 7 of 13 children in the NLD group made errors when attempting to construct figures with depth requirements. None of the other visual-spatial tests administered distinguished among the three groups of children. Based on the results from her study, Forrest (2004) suggested that the term NLD be reserved to describe the broader profile of assets and deficits. As mentioned earlier, she proposed developing a two-subtype model. The first category would be used for children whose visual-spatial deficits are primary and severe enough to affect academic performance. She also suggested a separate category, social processing disorder, for children whose social skill deficits are primary and impair their social interactions. The research presented supports Forrest’s (2004) proposal for a two-subtype model. Since the NLD syndrome features a wide range of symptoms, not every child given a diagnosis of NLD will look alike. Numerous individual differences exist 20 amongst children and adolescents with NLD. Therefore, separating NLD into subtypes, similar to Forrest’s model, may allow clinicians to focus on what is causing the child the most difficulty, whether it is their visual-spatial deficits, problems with social interaction, or another NLD deficit. More research is needed. Past investigations of NLD typically involve a battery of neuropsychological tests, achievement tests, and an inventory that measures psychological functioning. Few investigators have incorporated magnetic resonance imaging (MRI) into their investigations of NLD. Smith & Rourke (1995) has asserted that the types of deficits which would be likely seen in a patient with agenesis of the corpus callosum would be reflective of a white matter disturbance, and not focal dysfunctions. Panos et al. (2001) conducted a study, which evaluated the case of an 11-year-old boy with congenital agenesis of the corpus callosum, against Rourke’s (1995) NLD model. Based on Rourke’s White Matter Model, the authors predicted that the patient with acallosal would exhibit the signs and symptoms of NLD. In addition to using a comprehensive neurological assessment to identify NLD deficits, an MRI was completed to screen for structural brain abnormalities. The goal of their case study was not only to document the full range of neuropsychological performance of a young patient with congenital agenesis of the corpus callosum, but to compare his obtained results with Rourke’s (1989, 1995) NLD Model. At the time of assessment, K. an 11 year old White male, was hospitalized due to increasing out of control behavior and treatment failure at numerous other less-restrictive treatment programs. K. had a history of aggression towards others, fire setting, and hurting animals. According to the initial psychiatric assessment, K. was described as 21 having extreme hyperactive symptoms, as well as being “extremely oppositional.” He had also voiced suicidal ideation in the past. Previous diagnoses that K. carried included ADHD, Oppositional Defiant Disorder, and major depression. K. first began receiving mental health services when he was 4 years, 6 months old from a treatment center for hyperactive children. At that time he was experiencing attention problems, language and social skill delays, as well as severe encopresis. K. was placed on stimulants, which was reported to have had little success (Panos et al., 2001). K. was given a complete series of MRI scans. Neuroimaging analysis indicated a complete absence of the corpus callosum except for the presence of a small segment of rostrum. No other abnormalities were identified, and both gray and white matter development was reported as normal. It was noted that the left ventricle was “slightly larger,” and the right ventricle was “somewhat large.” The asymmetry of the ventricles suggested greater developmental disturbance to the right hemisphere. Neuropsychological assessment results indicated K. had mild attentional difficulty. Qualitatively, it was observed that many of K.’s attentional difficulties were related to processing speed demands. As such it was noted that K. only responded impulsively when he was under a timed demand. K. demonstrated both fine and gross motor movement difficulties, showing some level of impairment on most psychomotor measures. Regarding language functioning, K. showed significant language impairment including severe articulation and word finding difficulties. On measures of visual-spatial functioning, K. showed significant impairment in some activities requiring the organizing of visual-spatial information. Verbal memory deficits were also identified. K.’s academic performance followed the pattern predicted by the NLD model, with his 22 reading and spelling scores being approximately 10 standard score points above his arithmetic score. Interestingly, his intellectual performance was opposite of what was predicted, in that his PIQ score was 13 points higher than his VIQ score. The authors hypothesized that K.’s language deficits may explain some of this difference. Based upon neurological assessment findings, it was hypothesized that much of K.’s conductdisordered behaviors were due to his inability to appropriately respond to complex demands, particularly under conditions of high stimulation. It was also recognized that many of K.’s behavioral difficulties may have been related to his verbal expressive difficulties. In sum, the results of K.’s comprehensive neuropsychological assessment showed that he evidenced many of the predicted NLD deficits. K. had profound difficulty with integrative tasks such as visual-spatial organization. He also demonstrated attentional difficulties, a gross motor impairment, and the associated behavior problems. In addition, his MRI did not show any gross structural abnormalities, other than agenesis. Rourke has asserted that acallosal individuals, who are most expected to exhibit NLD, are those who do not have any other significant structural abnormalities. Thus, these results lend some support to the NLD model. In contrast to the NLD model, K. showed significant language impairment, weakness with verbal memory, and his PIQ score was higher than his VIQ score (Panos et al., 2001). Although there were many consistencies between the predicted impairments and K.’s actual performance, it was found that many of his neuropsychological deficits were more profound than what would have been expected based on Rourke’s model. For example, K. had extreme fine-motor difficulties, such as handwriting, that the NLD 23 model predicted would have improved with age. Additionally, the language impairments, such as word finding difficulties and articulation deficits, are clearly not associated with Rourke’s model. The authors ultimately concluded that although Rourke’s NLD model is descriptive of many aspects of white matter impairments, it may not account for the full range of deficits which may be observed (Panos et al., 2001). Nonverbal Learning Disability and Social Skills It has been well established that impairment in social interactions is highly correlated with NLD (Little, 1993). Rourke & Fuerst (1996) hypothesized that these deficits in social perception are a result of a particular pattern of neuropsychological assets and deficits in individuals with NLD. For example, their deficits in social judgment and social interaction may result from more basic problems in reasoning, concept-formation, and intermodal integration. Likewise, deficits in visual-perceptual organizational skills are thought to attribute to their problems in deciphering facial expressions, gestures, and other forms of nonverbal information important for effective communication. Petti, Voelker, Shore, and Hayman-Abello (2003) were interested in testing the theory that the visual-spatial deficits present in young children with NLD would manifest as social perception problems that in turn lead to social skills deficits and psychopathology. They used the Diagnostic Analysis of Nonverbal Accuracy (DANVA; Nowicki & Duke, 1994) to test this theory. The DANVA is a measurement of children’s ability to send and interpret nonverbal cues for 4 basic emotions (happy, sad, angry, and fearful). The purpose of Petti et al. (2003) investigation was to determine whether the DANVA receptive subtests would be useful in providing empirical evidence of 24 theoretically inferred social perception deficits in children with NLD. They hypothesized that children with NLD would be less skilled in interpreting nonverbal emotion cues than would either controls or children with VLD. A total of 33 participants between the ages of 9 and 14 participated in the study. The authors divided the participants into three groups: an NLD group, a VLD group, and a psychiatric controls group. There were 11 children in each group. Each group consisted of 5 females and six males. The four receptive tests of the revised DANVA (DANVA-2; Baum & Nowicki, 1998; Nowicki & Carton, 1993; Nowicki & Duke, 1994) were administered to each group. They included the Postures subtest, Gestures subtest, Facial Expressions subtest, and the Paralanguage subtest. It should be noted that no faces are seen on the Postures and Gestures subtest, and the Paralanguage subtest includes auditory recordings only. The Personality Inventory for Children – Revised (PIC-R; Lachar, 1982) was completed by all parents. The PIC-R is an objective multidimensional measure of behavioral and emotional functioning in children and adolescents. Results indicated that the participants were most accurate in interpreting visualspatial stimuli modeled by children, and least accurate in interpreting auditory stimuli modeled by adults. In addition, the NLD group was significantly less accurate (69%) in identifying adult facial emotion than was either the VLD group (78%) or the control group (80%), which did not differ from one another. Analysis of the Gestures subtest indicated a significant effect for group. The NLD group produced a significantly lower rate of accuracy identifying emotion conveyed through gestures (58%) than did either the VLD group (74%) or the control group (73%), which did not differ from each other. Finally, a one-way ANOVA was used to analyze group differences in errors made on the 25 Paralangual and Facial Expressions subtest in identification of emotions depicted with high versus low intensity. The analysis of low intensity adult facial expressions was significant F(2,30) = 3.39, p < .05. NLD children made significantly more errors (M = 4.09) than did control children (M = 2.72), but not compared to VLD children (M = 3.54). There were no significant results for the Postures subtest, but the scores were generally in the predicted direction with the NLD group showing the lowest accuracy scores (Petti et al., 2003). Multivariate Analysis of Variance (MANOVA) was used to examine group differences on the PIC-R factor scales. The pattern of group differences on the Social Incompetence factor was in the predicted direction, with NLD children rated as less skilled socially than either VLD or control children. The PIC-R scores also illustrated a high level of pathology in this sample. Finally, as predicted, the NLD group received a greater percentage of internalizing diagnoses (36.3%) than did the VLD group (18.1%) (Petti et al., 2003). Thus, results from this study lend empirical support to Rourke’s (1989, 1995) NLD model by providing evidence of specific nonverbal social perception deficits that distinguish children with NLD from those whose performance patterns might be attributable to a general maladjustment. The NLD group was less accurate than either the VLD or control group in inferring affect from adult facial expressions or gestures, and participants with NLD were twice as likely as those with VLD to be diagnosed as having an internalizing disorder. Virtually all results in Petti’s et al., (2003) study were in the predicted direction with the NLD group demonstrating the lowest level of nonverbal social perception skills. 26 In a more recent study, Bloom and Heath (2010) investigated adolescents’ abilities with NLD, general learning disabilities (GLD), and without LD to recognize, express, and understand facial expressions of emotion. Bloom and Heath (2010) hypothesized that a heterogeneous LD group would perform significantly worse in recognition, expression and understanding of facial expressions as compared with those without LD. They also hypothesized that adolescents with NLD would be less accurate at recognizing, expressing, and understanding facial expressions of emotion compared with those with a general LD subtype and those without LD. Participants consisted of 69 adolescents (males = 39, females = 30). The age range of participants was 12.0 to 15.9 years old. Participants were divided into the three aforementioned groups: NLD, GLD and without LD. The groups were evenly divided with 23 adolescents in each group. Each groups consisted of 13 boys and 10 girls. Results from this investigation did not support the hypothesis that adolescents with NLD would be less accurate overall at recognizing facial expressions compared to those with GLD or without a LD. Contrary to the prediction, it was discovered that adolescents with GLD were significantly worse at recognizing facial expressions than adolescents with NLD and without LD, with no difference between the NLD group and the group without LD. In addition, no significant difference was found between the three groups in their abilities to express facial expressions of emotion. The hypothesis that adolescents with NLD would be less accurate overall at understanding facial expressions of emotion compared to the GLD group and the group without LD also was not supported. Contrary to what was predicted, adolescents with GLD were significantly worse at understanding facial expressions of emotion as compared to the NLD group and 27 the group without LD. This result contradicts the aforementioned study by Petti et al. (2003), who found that the NLD group was significantly less accurate than were the VLD and controls in interpreting adult facial expressions and gestures. The results from these two studies supply mixed results. One reason for the conflicting results could be due to the differences in age in each study. Petti et al. (2003) study included younger participants. Their sample’s ages ranged from 9-14. Bloom & Heath’s (2010) investigation included participant’s between the ages of 12 and 15. Another reason that may account for the differing results is that the researchers used differing sets of diagnostic criteria. Since there is not a formal definition of NLD, researchers determine their own criteria for defining NLD. Inconsistent criteria may lead to inconsistent results. Another concern is instrumentation. Both sets of researchers used different assessment instruments to measure nonverbal emotional cues and visual spatial deficits. Finally, varying sample sizes could also lead to inconsistent results. Petti et al. (2003) sample consisted of 33 adolescents. Bloom & Heath’s (2010) sample consisted of 69 participants, which resulted in only 23 participants in each of their groups. Thus, there could be a variety of reasons for the inconsistent results. Nonverbal Learning Disability, Internalized Psychopathology, and Age Rourke & Fuerst (1991) stated that children with NLD are at risk for the development of significant psychopathology. Because children and adolescents with NLD have problems with intermodal integration, that is problems in the assessment of another’s emotional state through the integration of information gleaned from another’s facial expressions, tone of voice, and posture, they are more likely to misread social situations and react in a way that is inappropriate for the situation. In turn they can 28 experience social rebuffs. Such unfortunate outcomes are much worse when the child is anxious and confused in new or otherwise complex situations (Rourke, Young, and Leenaars, 1989). As an unfortunate consequence, these children tend to withdraw socially and experience social isolation. Rourke (1995) hypothesized that this marked isolation and withdrawal from social intercourse increases the likelihood of depression. In an article entitled, “Helping Children with Nonverbal Learning Disability: What I have learned from living with Nonverbal Learning Disability”, Lisa Marti (2004) gave a personal account of her experience growing up with NLD. She described experiencing three significant bouts of depression from adolescence to middle adulthood. The first bout of depression occurred when she was still in high school. She described it as “very bad” but not debilitating (p. 833). Lisa experienced her second bout of depression after college during her twenties. During this time she worked as a traveling sales representative. Eventually, her depression prevented her from driving long distances and she changed professions. Four years after that occurrence, Lisa described getting depressed again. During her third bout of depression, Lisa described having three job failures. Lisa stated that she lost a great deal of her thirties being debilitated by a combination of a sleep disorder, depression, and medication trials, and that she did not get diagnosed with NLD until she was 36. The diagnosis of NLD finally led her to get effective treatment and intervention. Lisa’s case is one example of an individual with NLD struggling with recurrent depression. Her story lends support to Rourke’s hypothesis that children with NLD are at risk for the development of socioemotional disturbance as they develop into adolescence. Below, several empirical investigations are reviewed that investigated age-related 29 differences in children and adolescents with NLD, and the relationship between age and internalized psychopathology in children and adolescents with NLD. Some of the investigations’ results provided support for Rourke’s model that the socioemotional deficits of individuals who manifest the NLD syndrome become exacerbated with age, while others indicated contrasting results. Casey et al. (1991) investigated whether and to what extent the features of NLD change in predictable directions during the middle childhood and early adolescent years. The authors hypothesized that there would be a relative stability in rote verbal skills, reading (word recognition), spelling and simple motor and tactile perceptual skills and abilities. In contrast, it was expected that there would be a relative decline in visualperceptual and problem-solving abilities, mechanical arithmetic skills, and complex psychomotor and tactile-perceptual abilities. Lastly, the authors hypothesized that there would be an increase in the severity of internalized forms of psychopathology, (e.g. social isolation, anxiety, depression), and an accompanying decrease in externalized forms of psychopathology. Thirty children/adolescents (males = 15, females = 15) were selected to participate in this study based on the following criteria: tactile perceptual deficits, psychomotor deficiencies, visuospatial/organizational deficiencies, good verbal capacities, and mechanical arithmetic deficiencies. (The authors acknowledged that the criteria used for participant selection was liberal and were not construed as the defining features of NLD.) For analysis of the cross- sectional data, two groups were formed based on age. The “young” group consisted of the 15 youngest children (M = 8.6 years, SD = 1.4; range = 5.9-10.5 years). Seven boys and 8 girls comprised the young group. 30 The “old” group consisted of the 15 oldest children (M = 12.6, SD = 1.4; range = 10.814.9 years). The old group comprised 8 boys and 7 girls. For the longitudinal data, ageeffects were evaluated by comparing the results of the first and second assessments. The second assessment took place approximately 2.3 years later from the original assessment. Only 9 of the original 30 participants were assessed for the longitudinal data (Casey et al., 1991). The results from this study provided support for the predictions that Casey et al. (1991) made regarding the hypothesized developmental changes of Rourke’s (1989, 1995) NLD model. Specifically, results found that with increasing age, the pattern of changes observed is such that there is relative stability of most verbal, simple tactile, and simple motor skills. Regarding academic skill, age appropriate gains were made in word recognition and spelling. In contrast, the older NLD children failed to make ageappropriate gains on neurocognitive measures that emphasized visual-perceptual, complex tactile and psychomotor, and problem solving skills and abilities. In addition, the older NLD children were found to be further behind their normally achieving agepeers in mechanical arithmetic skills as compared with the younger NLD children. These results are consistent with Rourke’s NLD model which states that it is rote, overlearned skills, at which NLD children are expected to become appropriately adept as they grow older. Conversely, they are expected to encounter increasing difficulty on tasks that are more novel or complex in nature that stress problem-solving abilities. Results also identified a clear pattern in the data reflecting the socioemotional and behavioral adjustment of the two groups. As predicted, the older children demonstrated an overall greater degree of socioemotional disturbance as compared with the younger 31 children. These disturbances were identified primarily as internalized behaviors. Contrary to what was predicted, the measure of externalized behavior did not decline. Rather, it was found to remain stable and within the clinically insignificant range over time (Casey et al., 1991). Results derived from the longitudinal data did not support the predictions made regarding age-related changes in neuropsychological, intellectual, and academic functioning. Both groups of children exhibited better performances at the second evaluation as compared with the first on measures that were predicted to remain stable. Thus, they demonstrated an accelerated development in those ability areas that were previously found to be adequate. In addition, these children showed a similar level of performance at follow up on those measures that were expected to decline. In other words, they continued to demonstrate mild-to-moderate deficits in areas that were initially identified as deficient (Casey et al., 1991). In a subsequent study, Tsatsanis, Fuerst, and Rourke (1997), also investigated the relationship between age and psychosocial functioning, but found contrasting results. Participants in their study consisted of 147 children with learning disabilities between the ages of 7 and 13. The children were divided into three age groups: Young (7 yrs – 8 yrs), Middle (9 yrs – 10 yrs), and Old (11 yrs – 13 yrs). Each child was assigned to one of seven psychosocial subtypes: Normal, Mild Anxiety, Mild Hyperactivity, Somatic Concern, Conduct Disorder, Internalized Psychopathology, and Externalized Psychopathology. Next, the mean ages of participants were calculated and compared. No significant differences were found in severity or type of psychosocial functioning with increasing age. However, the average age of subjects in the Somatic Concern and 32 Conduct Disorder subtypes tended to increase with age. Thus, Tsatsanis et al. (1997) found the opposite of the Casey et al. (1991) study. In the Tsatsanis et al., (1997) study, results indicated that the percentage of subjects in the Internalized Psychopathology subtype decreased with age. However, the percentage of participants in the Externalized Psychopathology, Somatic Concern, and Conduct Disorder subtypes increased with age. It should be noted that the Tsatsanis et al. (1997) sample was not divided into subtypes (e.g. NLD). The sample of children with learning disabilities was seen as constituting one group. In Casey et al. (1991) investigation the entire sample consisted of children who were classified as NLD. Pelletier, Ahmad, and Rourke (2001) investigated differential patterns of development of severe psychopathology in children with Basic Phonological Processing Disabilities (BPPD) and children with NLD over time. They hypothesized that the distribution of psychosocial subtypes (Normal, Mild Anxiety, Mild Hyperactivity, Somatic Concern, Conduct Disorder, Internalized Psychopathology, and Externalized Psychopathology) within the BPPD group and NLD group would differ in a predictable manner. Specifically, the children in the BPPD group were expected to exhibit relatively normal psychosocial functioning over time. In contrast, psychosocial functioning associated with the NLD group was expected to be of greater severity over time. The authors also hypothesized that the distribution of psychosocial subtypes within the BPPD group would remain relatively stable with increasing age, with no significant change in the type or severity of psychosocial disturbance over time. The NLD group, however, was expected to exhibit a trend towards increasing severity of psychopathology with advancing years. 33 Two hundred and eighty-six children were included in this study (BPPD = 213, NLD = 73). Per author report, the two groups did not differ significantly in terms of representation of gender, and numbers for the breakdown of gender within each group were not given. The Personality Inventory for Children (PIC; Wirt, Lachar, Klinedinst, & Seat, 1977) and the PIC-R (Lachar, 1982) were used as indicators of psychosocial functioning. Prototypical profiles for the seven psychosocial subtypes were produced when the mean scores on the 16 PIC scales were calculated for the previously mentioned subtypes. Children were then assigned to one of the seven prototypical psychosocial subtypes. For the BPPD group, results were as follows: Normal subtype (n = 73), Somatic Concern subtype (n = 28), Internalized Psychopathology subtype (n = 26), Mild Hyperactivity subtype (n = 25), Mild Anxiety subtype (n = 23), Externalized Psychopathology subtype (n = 21) and Conduct Disorder subtype (n = 17). For those in the NLD group who were assigned to a psychosocial subtype, the largest proportion was assigned to the Normal subtype (n=22). This was followed by 16 assigned to the Internalized Psychopathology subtype, 9 to the Externalized Psychopathology subtype, 8 to the Mild Hyperactivity subtype, and 6 to each of the Mild Anxiety, Somatic Concern, and Conduct Disorder subtypes. Not every child that was classified as exhibiting BPPD or NLD was assigned to a psychosocial subtype. A small number of subjects from both groups were rejected when their PIC profiles failed to match a prototype. When the distribution of psychosocial subtypes were compared between groups, it was observed that the only subtype that was disproportionately assigned was the Internalized Psychopathology subtype (X2 = 4.092, p < .05), with a significantly greater proportion of NLD subjects assigned to this subtype. Thus, providing support for the first hypothesis 34 that the profiles of children with NLD would exhibit a greater severity of internalized psychopathology than the BPPD group (Pelletier et al., 2001). In order to test the second hypothesis which addressed the influence of age on the distribution of psychosocial subtypes, each group was split into a “young” group (ages 912), and an “old” group (ages 13-15). Results indicated a significant trend toward increasing membership in the Somatic Concern subtype in the older age group of the BPPD group. There were no other significant differences found in the results of the analysis aimed at age trends in type or severity of psychosocial subtype membership. Thus, the second hypothesis was supported as it was expected that the psychosocial subtypes in evidence in the BPPD group would remain relatively stable with increasing age, and that no significant changes in the type or severity of pathology would be apparent. It was only the Somatic Concern subtype that demonstrated a significant trend toward increasing membership in the older group. (This result was consistent with findings from Tsatsanis et al. (1997), who found that the average age of participants in the Somatic Concern subtype in their study tended to increase with age.) For the NLD group, a significant trend toward membership in the Internalized Psychopathology subtype in the older group was evident (X2 = 9.735, p < .01). It was expected that the NLD group would exhibit a trend towards increasing Internalized Psychopathology with advancing age. The results provided strong support for this hypothesis. In addition, a comparison of the incidence of the Internalized Psychopathology subtype in the two groups at the older age level was significant (X2 = 25.97, p < .01) (Pelletier et al., 2001). Thus, the findings of Pelletier et al. (2001) study are consistent with those of Casey et al., (1991). Older children with NLD were found to exhibit internalizing forms 35 of psychopathology. This result supports the fundamental tenet that it is the particular pattern of neuropsychological assets and deficits exhibited by children with NLD that places them at greater risk for the development of internalized forms of psychopathology (Rourke, 1989, 1995). More recently, Klassen, Tze, and Hannok (2011) examined the association between internalizing problems and learning disabilities in adults. They conducted a meta-analysis that presented research comparing the internalizing problems (anxiety and depression) of adults with and without LD. The first purpose of their study was to examine support for two developmental hypotheses, abeyance and continuance. The abeyance hypothesis suggests that psychological problems associated with LD may decline in adulthood. The continuance hypothesis proposes that the incidence and impact of internalizing problems may continue after adolescence, and even worsen in adulthood. The second goal of their study was to explore the empirical literature on internalizing problems, specifically anxiety and depression, of adults with and without LD to establish the magnitude of difference between the two groups. The third and final goal of this study was to examine potential moderating effects on the internalizing problems of adults with LD. Their sample consisted of 15 studies, 8 journal articles and 7 dissertations, representing 1,379 adults with LD. The studies were published between 1989 and 2009 and included a total of 16,239 participants (LD group: n = 1,379; group without LD: n = 14,860). Potential moderating effects included: gender, status (postsecondary or general adult population), age, type of internalizing problem (anxiety or depression), anxiety type 36 (trait anxiety and state anxiety), and depression type (screening or clinical diagnosis) (Klassen et al., 2011). Results indicated that the post-secondary students and adults from the general population did not differ on the extent of experiencing internalizing problems. The results further indicated that the main effect size of experiencing internalizing problems were larger among college students with LD (d = 0.54, p < .001; d = effect size) and in the general adult population with LD (d = 0.46, p < .001) than in the related groups of peers without LD. To examine the age groups moderating variable, the authors disaggregated and regrouped the data into early adulthood (< 30 years) and middle adulthood (30+ years). Results indicated significantly higher levels of internalizing symptoms in early adulthood than in middle adulthood. Individuals with LD reported significantly more internalizing problems than their peers without LD. In contrast, no significant difference was found on the report of internalizing problems between individuals with LD and individuals without LD in middle adulthood. Regarding internalizing symptoms, the overall effect size for anxiety was significantly larger than that for depressive symptoms. In addition, adults with LD reported significantly higher levels of anxiety and depression than their peers without LD. Results further indicated that adults with LD reported a significantly higher level of trait anxiety than adults without LD. Finally, both types of depression (screening and clinical diagnosis) were significantly higher in adults with LD than in adults without LD. However, there was a significant moderator effect for the two types of depression, with the effect size for screening higher than the effect size for clinical diagnoses (Klassen et al., 2011). 37 Thus, the findings from this meta-analysis pointed to higher levels of internalizing disorders in adults with LD, compared to adults without LD. Additionally, results provided support for the continuance hypothesis, with little change in the magnitude of internalizing problems after high school ends. In other words, results indicated that the incidence of internalizing problems continued into adulthood, however, results did not show an increase in severity. Results also pointed to the continuing influence of LD on the psychological and emotional lives of adults with LD, regardless of postsecondary status. Lastly, results from this meta-analysis showed that internalizing problems are present in adult students with LD in rates similar to those adults with LD in the general population. In other words, being in college with access to various academic supports does not necessarily protect an individual with LD from experiencing internalizing problems (Klassen et al., 2011). In summary, various researchers have investigated age-differences in children and adolescents with NLD, and the relationship between age and internalized psychopathology in children and adolescents with LD/NLD and have received mixed results. The results from the above review indicated that there is a difference in the way younger and older groups of children manifest NLD. This review also provided support for the hypothesis that socioemotional disturbance increases with age in children and adolescents with NLD (Casey et al., 1991; Pelletier et al., 2001). Both of these studies found that older children exhibited an overall greater degree of socioemotional disturbance. Some procedural differences were noted in both studies. Both the Casey et al. (1991) study and the Pelletier et al. (2001) study used different criteria to classify NLD. Casey et al., (1991) acknowledged using more liberal criteria to classify 38 participants into the NLD group (see Appendix B; see Appendix C for a list of the rules Pelletier et al., (2001) used for classification in their investigation.) Even with the more strict and updated criteria, results in the Pelletier et al. (2001) investigation were similar to Casey et al. (1991) regarding age differences and developmental trends in children with NLD. Conversely, Tsatsanis et al. (1997) did not find any significant differences in severity or type of psychosocial functioning with increasing age. In their study, internalized psychopathology decreased with age. However, it should be noted that their sample was not broken down into subtypes of LD (e.g. NLD or BPPD). Their LD sample was seen as constituting one group. In contrast to Tsatsanis et al. (1997) study, Klassen et al. (2011) was not separated into LD subtypes either. However, their results were more consistent with Casey et al. (1991) and Pelletier et al. (2001). Despite not being broken into subtypes, results still indicated that individuals with LD continue to experience higher levels of internalizing disorders into adulthood compared to their adult peers without LD. Purpose of Study Nonverbal Learning Disability is a theorized subtype of learning disability that causes serious social challenges for children and adolescents that manifests its symptoms. It has been hypothesized that younger groups of children manifest the symptoms of NLD differently than older groups of children. For example, Rourke (1995) suggested that children with NLD are perceived as hyperactive during early childhood, and become less active and eventually hypoactive. Rourke et al. (1989) further suggested that children 39 and adolescents with NLD are at risk for the development of internalized psychopathology, such as anxiety and depression. The following is an exploratory study of the social, emotional, and behavioral features of NLD in children and adolescents. Although past studies have shown an increase in internalized psychopathology with age, not as many studies discuss the manifestation of externalizing symptoms. The purpose of the following study is to explore age-related social differences in two groups of children, a “younger” group and an “older” group. Specifically, behavioral, social, and emotional variables will be investigated. Psychiatric comorbidities will also be investigated. Research Questions 1. What are the age-related behavioral (e.g. conduct problems, delinquent behavior, aggression) differences between the “younger” group of children (ages 6 – 10) and the “older” group of children (ages 11 -16) diagnosed with NLD? 2. What internalized emotional problems do children with NLD display and do these differ by age group? 3. What social problems do children and adolescents with NLD experience, and do these problems differ by age group? 4. What psychological disorders commonly occur with NLD and do these differ by age group? 40 CHAPTER III METHODOLOGY This study was designed to investigate the age-related social, emotional, and behavioral characteristics in children and adolescents with NLD. To guarantee confidentiality of participants, all procedures were evaluated and approved by the University of Iowa’s Institutional Review Board before access to patient files was given. The following is a detailed description of the participants, measures, and procedures. Participants Participant records were selected from existing data files of individuals who have been evaluated through the Pediatric Attention/Learning Disabilities clinic affiliated with the Division of Pediatric Psychology at a large university hospital located in the Midwestern part of the United States. Approximately 1,000 patient charts were looked through. The final sample consisted of 72 outpatient records (males = 41, females = 31). Thus, 7.2% of the charts that were searched consisted of patients with a diagnosis of NLD. The ages of participants ranged from 6 – 16 years. Grade placement ranged from kindergarten to 11th grade. The race/ethnicity of each participant was unknown. Measures The following measures were used to screen participants into the Nonverbal Learning Disability group: Wechsler Intelligence Scale for Children-Fourth Edition, Judgment of Line Orientation Test, Grooved Pegboard Test, Boston Naming Test, Bender Visual Motor Gestalt Test, Word Fluency Test, the Delis Kaplan Executive Function System, and the Developmental Test of Neuropsychological Assessment-Second Edition. 41 The Pediatric Behavior Scale-Parent Version was used to analyze the research questions. The psychometric properties of these measures are described below. Wechsler Intelligence Scale for Children - Fourth Edition The Wechsler Intelligence Scale for Children – Fourth Edition, (WISC-IV; Wechsler, 2003) is an individually administered standardized measure of general intellectual functioning. It is designed for children and adolescents aged 6 years 0 months to 16 years 11 months. In addition to providing a Full Scale IQ, it also provides four index scores. The four index scores are the Verbal Comprehension Index (VCI), the Perceptual Reasoning Index (PRI), the Working Memory Index (WMI), and the Processing Speed Index (PSI). The VCI is composed of subtests measuring verbal abilities utilizing reasoning, comprehension, and conceptualization. The PRI is composed of subtests measuring perceptual reasoning and organization. The WMI is composed of subtests measuring attention, concentration, and working memory. The PSI is composed of subtests measuring the speed of mental and graphomotor processing. The WISC-IV has 10 core subtests and five supplemental subtests. Similarities, Vocabulary, and Comprehension are the three core subtests that comprise the Verbal Comprehension Index. The three core Perceptual Reasoning subtests are Block Design, Picture Concepts, and Matrix Reasoning. Digit Span and Letter-Number Sequencing are the two core Working Memory subtests, and Coding and Symbol Search are the two core Processing Speed subtests. All 10 core subtests comprising the four indices contribute equally to the Full Scale IQ. The WISC-IV includes two supplemental Verbal Comprehension subtests: Information and Word Reasoning. Picture Completion is the supplemental Perceptual 42 Reasoning subtest. Arithmetic is the supplemental Working Memory subtest, and Cancellation is the supplemental Processing Speed subtest. Up to one supplemental subtest may be substituted for a core subtest in composites. The WISC-IV normative data were established using a sample collected from August 2001 to October 2002. The sample was stratified on key demographic variables (i.e. age, sex, race/ethnicity, parent education level, and geographic region) according to the March 2000 U.S. census data. For the overall standardization sample, the average reliability coefficients of the WISC-IV subtests range from .79 (Symbol Search and Cancellation) to .90 (LetterNumber Sequencing). The authors report that all the remaining reliability coefficients are good, ranging from .80 (Word Reasoning) to .89 (Vocabulary and Matrix Reasoning). Retest data are reported for all ages and for five separate age groups, 6:0-7:11, 8:0-9:11, 10:0-11:11, 12:00-13:11, and 14:0-16;11. Per authors report, the data indicate that the WISC-IV scores possess adequate stability across time for all five age groups. Per author report, the majority of subtests included in the WISC-IV have strong theoretical and empirical evidence of validity based on response processes. Additional evidence of validity was accumulated through empirical and qualitative examination of response processes during the scale’s development. “Research utilizing the Wechsler scale has provided strong evidence of validity based on the scales’ internal structure” (p. 48). Judgment of Line Orientation The Judgment of Line Orientation Test (JLO; Benton, Hannay, & Varney, 1975) was designed to assess the capacity to judge the spatial orientation of lines in relation to a 43 set of standard references. It is presented as a visual matching task and makes no demands on short-term memory. There are two forms of the test, Form H and Form V, which consist of the same 30 items presented in a different order. However, in the case of each form, the items are presented in a generally ascending order of difficulty. The test materials of each form are in a spiral–bound booklet consisting of 35 stimulus pictures appearing on the upper part of the open booklet and 35 corresponding responsechoice displays appearing on the lower part of the booklet. The first five items are practice items. Each of the five practice items consists of complete reproductions of a pair of full-length lines appearing on the multiple-choice response card. The practice items are the same for both forms of the test. Following these practice items are the 30 test items. Each of the subsequent 30 test items consists of a pair of partial lines, with each partial line corresponding to the orientation of one of the lines appearing in the multiple-choice response card below it. Each partial line represents, with respect to the origin, either the distal, the middle, or the proximal 3/4in. (1.9cm) segment of a responsechoice line (Benton, Hamsher, Varney, and Spreen, 1983). Each item is worth one point. Thus, the range of scores is zero to thirty. Regarding its psychometric properties, corrected split-half reliability of Form H in a sample of 40 subjects was found to be .94. The same statistic for Form V in a sample of 124 subjects was .89. In the combined sample of 164 subjects, the corrected split-half reliability was .91, the standard error of measurement being 1.7. It was further reported that a sample of 37 patients was given both forms of the test, the interval between test and retest ranging from 6 hours to 21 days. The mean scores for the first and second administrations were reportedly almost identical (23.1 and 23.5) indicating the absence of 44 a systematic practice effect. The test-retest reliability coefficient was .90 with a standard error of measurement of 1.8 points (Benton et al., 1983). Riccio and Hynd (1992) conducted an experiment to further investigate the validity of the JLO. Specifically, this study addressed validity of the JLO in terms of construct and criterion-related validity with 73 children. Participants for this study were clients from a southern university clinic and the surrounding university community. Participants were divided into three groups: the clinic-referred learning-disabled group, the clinic-referred non-learning disabled group who had a psychiatric diagnosis, and a control (normal) group. Regarding construct validity, the authors anticipated that results of the JLO would correlate most highly with other commonly used measures of visualperception, specifically, the Wechsler Intelligence Scale for Children-Revised (WISC-R; Wechsler 1974) performance subtests and the Beery Developmental Test of Visual Motor Integration (VMI; Beery 1989). It was also expected that the JLO would correlate least with measures of language ability. The authors were correct in their hypotheses. Results of the study indicated that the JLO correlates moderately with a number of other measures used to assess visual perception (i.e. select performance subtests from the WISC-R). However, in contrast to other studies that found measures of visual perception and measures of visual motor integration to assess predominately different behavior, the JLO correlated most with the VMI (r = .52, p < .001). The JLO correlated least with the Coding subtest of the WISC-R and the Peabody Picture Vocabulary TestRevised (PPVT-R; Dunn & Dunn, 1981). This finding is consistent with predictions. Regarding criterion-related validity, the JLO was found to correlate significantly with math ability as measured by the Basic Achievement Skills Screener (BASIS; 45 Psychological Corporation, 1983) and the Wide Range Achievement Test-Revised (WRAT-R; Jastak & Wilkinson, 1984). The JLO also correlates moderately with reading, but not spelling as measured by the Woodcock Reading Mastery Tests-Revised (WRMTR-R; Woodcock, 1987). Thus, it appears that the JLO has sufficient construct and criterion-related validity with the population the authors used for this study. Regarding discriminate validity, the JLO did not discriminate among normal controls, clinic-referred children with psychiatric disorders, and clinic-referred children with learning disabilities. Grooved Pegboard Test The Grooved Pegboard Test (Klove, 1963) is a brief, portable measure of finger dexterity. It measures eye-hand coordination and also assesses motor speed. It takes approximately five minutes to administer and may be given to individuals between the ages of 6 and 85. The Grooved Pegboard Test consists of a metal board with a matrix of 25 holes with randomly positioned slots. Pegs have a ridge along one side and must be rotated to match the hole before they can be inserted. The test taker is instructed to insert the metal pegs, matching the groove of the peg with the groove of the hole, as quickly as possible, without skipping any slots. The dominant hand is tested first followed by the nondominant one. The test taker continues until all pegs have been placed. The score is the time in seconds required to complete the array with each hand (Strauss, Sherman, & Spreen, 2006). Levine, Miller, Becker, Selnes, and Cohen (2004) investigated practice effects for the Grooved Pegboard Test. Their results indicated that test-retest correlations were not very good. The dominant hand trial of the Grooved Pegboard had a test-retest reliability 46 of less than .67 (r = .73 nondominant hand). The time between testing was between 7 and 8 months. In contrast, Dikmen, Heaton, Grant & Timkin (1999) found better reliability in their investigation with Grooved Pegboard (R = .86). The Grooved Pegboard Test manual is limited in providing validity data (Mahurin & McClure, 2004). Boston Naming Test The Boston Naming Test (BNT; Kaplan, Goodglass, & Weintraub, 1983) assesses visual naming ability using black and white drawings of common objects. The current version, (BNT-2), contains 60 items and includes a short 15-item version, as well as a multiple-choice version. The stimuli consist of line drawings of objects with increasing difficulty, ranging from simple, high-frequency vocabulary words (e.g., comb) to rare words (e.g., abacus) (Strauss, Sherman, & Spreen, 2006). Halperin, Healy, Zeitschick, E., Ludman, & Weinstein (1989) investigated construct validity of the BNT in children. The test loaded highly on a word knowledge, or vocabulary factor together with the PPVT-R, but showed low loadings on a verbal fluency or a memory factor, suggesting that it is a relatively pure measure. In another investigation, Axelrod, Ricker, & Cherry, (1994) found that the BNT has strong concurrent validity (r = .86) with the Visual Naming Test of the Multilingual Aphasia Examination (MAE; Benton, Hamsher, & Sivan, 1994). Bender Visual Motor Gestalt Test The Bender Visual Motor Gestalt Test (BVMG: Bender, 1938) was one of the first and most widely studied tests of drawing. The BVMG has many uses. It serves as a visuoconstructional task for neuropsychological assessment and as a neuropsychological screening measure. (Lezak, Howieson, & Loring, 2004). The Bender consists of nine 47 geometric figures which are presented to the examinee one at a time on an index card. The examinee is then asked to copy each figure on a blank piece of paper. A number of specific errors is identified for each design (i.e. distortion of shape, rotation, integration of parts, perseveration). Thus, the BVMG is scored according to the number of errors the examinee makes. A high score indicates a poor performance while a low score reflects a good performance. The test is untimed. The Bender has had two traditional uses in childhood assessment: as a test of visual-motor development and as a projective personality technique (Rossini & Kasper, 1987). The Bender has also been used in the assessment of brain injury and to diagnose reading and learning problems in children (Koppitz, 1964). The Bender II (Brannigan & Decker, 2003a), Copy phase, which was used for the current study, is significantly different from the original Bender. The new edition still contains the original designs. However, seven new designs have been added to increase the range of assessment. There are four specific designs for use at lower ages (4 years to 7 years, 11 months), whereas there are three new designs for use at the upper range of administration (8 years to 85+ years of age). The original Bender was created for children 5 years, 0 months to 10 years, 11 months. The Bender II also includes a behavioral observation form for use during test administration (Brannigan & Decker, 2003b). The Bender II uses a Global Scoring System (GSS). Examiners use the GSS to evaluate the overall representation of each design the examinee produces during the Copy and Recall Phases of administration. The GSS consists of a 5 point rating scale that is designed to yield individual scores for each item and a total score for each test. 48 Regarding psychometric properties, the Bender has high reliability and high internal consistency. Interrater consistency estimates ranged from .83 to .94, with a mean of .90 for the Copy phase. The range was .94 to .97 with a mean of .96 for the Recall phase. Split-half reliability coefficients across age level ranged from .86 to .95. Mean test-retest coefficients (with a 2-3 week time period) for the Copy phase were .85 and .83 for the Recall phase. Validity studies suggested that the Bender-Gestalt II served as a valid measure of visual-motor integration, especially for the Copy portion of the instrument (Brannigan & Decker, 2003b). Word Fluency Test The Word Fluency Test, also referred to as the Controlled Oral Word Association Test (COWA; Benton & Hamsher, 1976; Spreen & Strauss, 1998) is an oral fluency test that evaluates the spontaneous production of words beginning with a given letter within a limited amount of time. The test taker is asked to produce orally as many words as possible beginning with the letters, F, A, and S, and is allowed one minute for each letter. Participants are instructed not to use proper names. Nor are participants allowed to use the same word with a different ending. Test takers receive one point for each correct word and the score is the sum of all admissible words for the three letters (Spreen & Strauss, 1998). Normative standards on the FAS-COWA were reported by Gaddes & Crocket (1975). They studied a random group of 373 school children without learning deficits (females = 179, males = 174). Normative data results indicated an increase in score as the age of the child increased. Results further indicated a slightly lower score for females compared to males (Gaddes & Crocket, 1975). Regarding psychometric properties, 1- 49 year retest reliability in older adults has been reported as .7, and retest reliability after 1942 days in adults as .88 (des Rosiers and Kavanagh, 1987). Delis Kaplan Executive Function System The Delis-Kaplan Executive Function System (D-KEFS; Delis, Kaplan, & Kramer, 2001) assesses higher-level cognitive functions in both children and adults. The D-KEFS offered the first nationally normed set of tests designed exclusively for the assessment of executive functions. The national standardization study of the D-KEFS included over 1,700 children and adults, from ages 8 to 89 years, carefully selected to match the demographic characteristics of the U.S. population. The D-KEFS consists of nine tests that measure a wide spectrum of verbal and nonverbal executive functions. Each test is designed to be a stand-alone instrument that can be administered individually or along with other D-KEFS tests. The Verbal Fluency Test from the D-KEFS was used to assist in screening participants into the NLD group. The D-KEFS Verbal Fluency Test is composed of three conditions: Letter Fluency, Category Fluency, and Category Switching. For the Letter Fluency condition, the examinee is asked to say words that begin with a specified letter as quickly as possible in three trials of 60 seconds each. In the Category Fluency condition, the examinee is asked to say words that belong to a designated semantic category (e.g. animals) as quickly as possible in two trials of 60 seconds each. The last condition, Category Switching, is a means of evaluating the examinee’s ability to alternate between saying words from two different semantic categories (e.g. fruits and furniture) as quickly as possible for 60 seconds (Delis et al., 2001). 50 The various subtests of the D-KEFS, including Verbal Fluency, have an astounding number of scores. Whereas the principal scores generally have acceptable reliability, the additional D-KEFS scores often have low reliability which varies across age groups. For some of the nine subtests, standard deviations of test-retest scores were larger for the second testing, which suggests weak reliability. For example, Condition 1: Letter Fluency had an SD = 2.61 at the first testing. The SD increased to 2.86 at the time of the second testing. Internal consistency scores varied by age group. For example, internal consistency values for the D-KEFS Fluency Test range from .68 (age = 8) to .86 (age range 80-89). Regarding validity, time-interval measures had a moderate to high correlation with overall achievement scores (Delis et al., 2001). NEPSY II The NEPSY Second Edition (NEPSY-II; Korkman, Kirk, & Kimp, 2007) is the revision of the NEPSY (Korkman, Kirk, & Kimp, 1997), a comprehensive instrument designed to assess neuropsychological development in preschool and school-age children. The name NEPSY is formed from the word neuropsychology, taking NE from neuro and PSY from psychology. Results obtained from a NEPSY-II assessment inform diagnosis and aid in intervention planning for a variety of childhood disorders. In particular, the NEPSY-II provides the clinician with insight regarding academic, social, and behavioral difficulties (Korkman et al., 2007). The NEPSY-II consists of a series of neuropsychological subtests that can be used in various combinations according to the needs of the child and the experience of the examiner. The subtests were designed specifically for children between the ages of 3 and 16. A broad range of subtests is included to assess neuropsychological development 51 across six functional domains: Attention and Executive Functioning, Language, Memory and Learning, Sensorimotor, Social Perception, and Visuospatial Processing (Korkman et al., 2007). Subtest scores are organized around the six functional domains to assist in the differential diagnosis of childhood disorders such as ADHD, Pervasive Developmental Disorders, Language Disorder, Mathematics Disorder, and Reading Disorder, among other developmental and acquired disorders. The NESPY-II enables the clinician to focus on specific cognitive abilities related to general referral questions. The examiner is not required to administer every subtest, only those relevant to the current referral question. Subtest scores, rather than global index or domain scores, are used to determine a child’s strengths and weaknesses. This enables the examiner to customize the assessment to each child’s needs and to shorten or lengthen testing as desired (Korkman et al., 2007). The Arrows subtest from the NESPY-II was used to assist in screening participants into the NLD group. The Arrows subtest is designed to assess the ability to judge line orientation. The child looks at an array of arrows arranged around a target and indicates the arrow(s) that points to the center of the target (Korkman et al., 2007). According to the authors, the subtests were normed on a single, well-stratified sample. This provided a comprehensive view of neuropsychological processes in children and patterns of age-related quantitative and qualitative changes in neuropsychological performance. The NEPSY-II was standardized in conjunction with a number of validity measures, including the WISC-IV, the Differential Abilities Scales-Second Edition (DAS; Elliott, 2007), the Wechsler Individual Achievement Test-Second Edition (WIAT- 52 II; Harcourt Assessment, 2005), the Children’s Memory Scale (CMS; Cohen, 1997), and the DKEFS. The NEPSY-II is designed to help identify cognitive deficits related to disorders that are typically first diagnosed in childhood and that may limit a child’s academic success (Korkman et al., 2007). The results of the reliability studies indicated that most of the NEPSY subtests have moderate to high internal consistency or stability. The subtests that have the highest reliability coefficient are Phonological Processing, Memory for Names, and List Learning. Overall the lowest reliability coefficients are on subtests on which test-retest correlation was used (e.g. Design Fluency, Verbal Fluency, and Fingertip Tapping). Results of research studies indicated that the NEPSY exhibited evidence for convergent and discriminate validity (Korkman et al., 1998). Dependent Variables The Pediatric Behavior Scale- Parent Version was used to analyze the variables of interest in this study. These dependent variables include: externalizing behaviors, internalizing emotional behaviors, and various social behaviors. Pediatric Behavior Scale-Parent Version The Pediatric Behavior Scale (PBS: Lindgren & Koeppl, 1987) was developed to assess child behavior problems in a medical setting and is used as a measure of social and emotional functioning. The PBS consists of 165 items that assess problems in 24 behavioral dimensions in six general areas: Conduct, Attention Deficits, DepressionAnxiety, Deviation, Health, and Cognition (See Appendix D). Parents rate their child’s behavior using a four-point scale, ranging from 0 (“Almost never or not at all”) to 3 (“Very often or very much”). Raw scores are converted to T scores. Children whose T 53 scores were rated to be between 63 and 69 are considered to be in the “at-risk” range for that particular behavior. Behaviors rated in the “at-risk” range are not severe enough to warrant a clinical diagnosis. Rather, behaviors in this range alert the parent and clinician that these behaviors have the potential to become severe, and that the child may need careful monitoring. T scores that are 70 and above are considered to be in the clinical range. Children, whose scores are rated to fall in this range, may be in need of clinical intervention and alerts the clinician that further assessment in this area may be warranted before a formal diagnosis is given. The PBS takes approximately 15-20 minutes to complete. In addition to gaining information on behavior problems, it also obtains information regarding socioeconomic status, educational functioning of the child, and medications taken regularly. The basic scale is for children between 6 and 16 years of age, and a preschool scale is available for children between 3 and 5 years of age (Lindgren & Koeppl, 1987). Preliminary data on the Pediatric Behavior Scale were derived from 106 pediatric patients (86 boys and 20 girls) evaluated by the Divisions of Pediatric Neurology, Pediatric Psychology, and Developmental Disabilities at the University of Iowa. Children with significant mental retardation were excluded from the sample. The children ranged in age from 6 to 16 years, with a mean age of 9.74 years. The mean maternal education for the sample was 12.90 years (SD=1.84) (Lindgen & Koeppl, 1987). Children in the sample had varied in their medical and psychological diagnoses. Using the same clinic sample, the median internal consistency coefficient was .83 for the specific scales on the PBS and .91 for the general factors. Interrater reliability was estimated based on the scores of 33 children for whom both parents completed a 54 PBS. Correlations between mother and father ratings for all six of the PBS general factors were highly significant (p < .001). The specific correlations were as follows: conduct .79, attention/impulsivity .76, depression/anxiety .73, deviation .58, health .51, cognition .69 (Lindgren & Koeppl, 1987). After researching and comparing the PBS to other highly valid checklists (i.e. Child Behavior Check List (CBCL; Achenbach & Edelbrock, 1983; and the Personality Inventory for Children (PIC; Wirt, et al., 1977), and through pilot testing and expert reviews, a selection of 165 items were included on the PBS. No new norms have been published since the scales development. Procedures The data for this study came from records of youth seen at the Pediatric Attention/ Learning Disabilities clinic within the last 10 years. Approximately 1,000 patient records were reviewed. The inclusion/exclusion criteria are listed below. In order to be included in this study, patient records needed to meet the following criteria: (a) WISC-IV Global Assessment score (GAI) within the Low Average to Superior Range (85 and above); (b) no primary sensory disabilities; (c) English as primary language; and (d) completed PBS. Participants were assigned to the NLD group based on the following criteria: (1) they had previously been given a diagnosis of NLD by a psychologist, (2) at least a 13point discrepancy between Verbal Comprehension (VCI) and Perceptual Reasoning (PRI) index scores whereby VCI is higher than PRI, (3) demonstrated average to above average performances on three or more of the following associative and expressive language measures: Vocabulary, Similarities, and Information subtests of the WISC-IV, Word Fluency Test, Verbal Fluency Test of the DKEFS, Boston Naming Test, and (4) 55 performed at least one or more standard deviations below the mean on three or more of the following visual/spatial-motor examinations/subtests: Bender Visual Motor Gestalt Test, Judgment of Line Test, Grooved Pegboard Test, NESPY-II Arrows subtest, Block Design, Matrix Reasoning, Picture Completion, and Picture Concepts of the WISC-IV. It should be noted that past researchers have used only a 10 point discrepancy between the VCI and PRI as a defining characteristic of NLD, though this difference is not statistically significant. The current study uses more stringent criteria in which participants must have at least a difference of 13 points between their VCI and PRI, with the VCI being greater. In addition, if WISC-IV subtests scores were missing from patient charts and the VCI or PRI could not be deciphered, patients were only included if there was at least a 30 point discrepancy between their VCI and PRI. After patient charts were selected for inclusion in the study, they were divided into groups based on the patient’s age. Children between the ages of 6 and 10 were included in the “younger” group. The “older” group consisted of participants between the ages of 11 and 16. Data Analysis The first goal of the current study was to evaluate potential age-related behavioral (e.g. conduct problems, delinquent behavior, aggression) differences between the “younger” group of children and the “older” group of children diagnosed with NLD. This analysis was completed by examining the following scales on the PBS: Oppositional Behavior, Aggression, Explosiveness, Attention, Impulsivity, and Hyperactivity. Descriptive analyses were used to first identify externalizing behaviors in each group. Next, a one factor Multivariate Analysis of Variance (MANOVA) was run to investigate 56 whether age-related differences exist. The independent variable in the MANOVA was age. The dependent measures were the six externalizing behavior scales: Oppositional Behavior, Aggression, Explosiveness, Attention, Impulsivity, and Hyperactivity. The second goal of the study was to identify what internalized emotional problems children and adolescents with NLD display, and investigate whether these behaviors differed by age group. This analysis was completed by examining the following scales on the PBS: Tension, Anxiety, Self-Esteem, Depression, and Social Isolation. Descriptive analyses were used to first identify internalizing behaviors in each group. Next, a one factor MANOVA was performed to investigate age-related differences. The independent variable in the MANOVA was age. The dependent measures were the five internalizing scales. The third goal of this study was to determine whether two different age groups of children/ adolescents with NLD experienced differing social problems. To investigate this question, parent ratings on the PBS were examined. Specifically, the Inappropriate Social Behavior scale and the Perseveration scale were examined. Descriptive analyses were used to identify social problems experienced by children and adolescents with NLD. A Univariate Analysis of Variance (ANOVA) was performed to measure items on the Inappropriate Behavior Scale. An ANOVA was also run to measure items on the Perseveration scale. The fourth goal of this study was to determine what psychological disorders commonly occur with NLD, and investigate whether these disorders differed by age group. This final research question was analyzed by investigating and documenting the 57 various diagnoses given to participants who were evaluated in the Pediatric Attention/Learning Disabilities clinic. Percentages were reported. Supplemental Research Question Post hoc analyses were conducted after the original four questions were investigated. Of interest to the investigation was how the current NLD sample compared to the normative sample on the externalizing and internalizing scales of the PBS. The normative sample consisted of a general pediatric patient sample. Means and standard deviations were compared to see if differences existed between the two populations. 58 CHAPTER IV RESULTS This chapter presents the results of the statistical analyses used to evaluate the research questions established in the previous chapters. First, demographic characteristics of the sample are presented. Second, the findings of the four research questions are addressed. Third, findings from the supplementary research question are identified. Demographic Data The participants were 72 outpatients in the Department of Pediatric Psychology at the University of Iowa Hospitals and Clinics who met the inclusion criteria. Participants were included in the study if: (1) their patient record included a completed Pediatric Behavior Scale- Parent Version, (2) they had previously been given a diagnosis of NLD by a psychologist, (3) they had at least a 13-point discrepancy between Verbal Comprehension Index (VCI) and Perceptual Reasoning Index (PRI) scores whereby VCI is higher than PRI on the WISC-IV, (4) they demonstrated average to above average performances on three or more associative and expressive language measures, and (5) they performed at least one or more standard deviations below average on tests of visualmotor integration, fine motor coordination, and visual-spatial skills. The participants included 41 boys/adolescents and 31 girls/adolescents ranging in age from 80 months to 195 months (M = 133, SD = 28.5). Grade placement ranged from kindergarten to eleventh grade. Overall, the mean grade placement was the fifth grade, and the median grade placement was the fifth grade. The mode was the fourth grade (n = 16). The VCI of participants ranged from 85 to 146 (M = 108, SD = 14.8). The PRI 59 ranged from 57 to 106 (M = 80.9, SD = 10.4). All participants were diagnosed with NLD. Participants were divided into groups based on their age. The “younger” group (n = 38) included participants between the ages of 6 and 10 (M = 9, SD = 1.3). The “older” group (n = 34) consisted of participants between the ages of 11 and 16 (M = 13, SD = 1.5). Question One The purpose of question one was to investigate the age-related behavioral (e.g. conduct problems, delinquent behavior, aggression) differences between the “younger” group of children and the “older” group of children. To answer this question, parents’ responses on the PBS were examined. Descriptive analyses were performed to first identify externalizing behaviors in each group. The mean (T Score) of each externalizing behavior subscale (Oppositional Behavior, Aggression, Explosiveness, Attention, Impulsivity, Hyperactivity) for the “younger” and “older” group is shown in Table 1. As can be seen in the table, the “younger” group’s mean T score (M = 63.3, SD = 11.4) falls in the “at-risk” range on the Explosiveness subscale. Both the “younger” and “older” groups fall in the “at-risk” range on the Attention subscale (M = 69.58, SD = 12.1; M = 69.85, SD = 11.9 respectively). Lastly, the “younger” group’s mean T score (M = 64.01, SD = 10.9) falls in the “at-risk” range on the Impulsivity subscale. Neither group’s mean T score reached the clinically significant range. Next, a one factor MANOVA was run to investigate whether these externalizing behaviors differed by age group. The independent variable in the MANOVA was age. 60 The dependent measures were the six externalizing behavior subscales: Oppositional Behavior, Aggression, Explosiveness, Attention, Impulsivity, and Hyperactivity. The Table 1 Mean T Scores for Each Age Group for Externalizing Behaviors Age Group Externalizing Scale Oppositional Behavior Aggression Explosiveness Attention Impulsivity Hyperactivity Note. At-Risk Range = 63-69 Clinical Range = 70-90 Younger M 61.14 60.16 63.26 69.58 64.01 60.55 Younger SD 10.6 11.4 11.4 12.1 10.9 10.9 Older M 59.41 57.79 59.9 69.85 61.91 58.71 Older SD 8.9 9.2 11.1 11.9 11.2 10.2 results of the MANOVA did not yield any significant differences F(1, 70) = .85, p < .05. Thus, results suggest that children in the “younger” and “older” groups manifest these externalizing behaviors in a similar manner. In addition, results indicate that minor problems with attention, may not change across development. Question Two The purpose of question two was to investigate what internalized emotional problems children and adolescents with NLD display and to determine whether these behaviors differed by age group. Parent ratings on the PBS were used to analyze this research question. Specifically, the following subscales were examined: Tension, Anxiety, Self-Esteem, Depression, and Social Isolation. Descriptive analyses were performed to first identify any internalized emotional problems. The mean (T Score) of 61 each internalizing behavior scale for the “younger” and “older” group is shown in Table 2. Both the “younger” and the “older” group scored in the at-risk range on the SelfEsteem scale (M = 63.46, SD = 11.7; M = 63.53, SD = 11.5 respectively). The “older” group’s T score mean fell in the at-risk range on the Social Isolation scale (M = 64.5). Neither group’s mean T score reached clinical significance. Table 2 Mean T Scores for Each Age Group for Internalizing Behaviors Internalizing Scale Tension Anxiety Self-Esteem Depression Social Isolation Note. At-Risk Range = 63-69 Clinical Range = 70-90 Younger M 61.78 60.57 63.46 58.63 62.26 Age Group Younger Older SD M 8.6 10.3 11.7 9.8 11.5 61.68 60.15 63.53 60.04 64.5 Older SD 8.70 9.02 11.5 8.7 9.9 Next, a one factor MANOVA was performed to investigate age-related differences. The independent variable in the MANOVA was age. The dependent measures were the five internalizing scales: Tension, Anxiety, Self-esteem, Depression, and Social isolation. The results of the MANOVA did not yield any significant results F(1, 70) = .980, p < 0.05. Thus, results suggested that children in the “younger” and “older” groups manifest these internalizing behaviors in a similar manner. Additionally, results indicate that minor problems with self-esteem may follow children into adolescence. 62 Question 3 The purpose of question three was to investigate the social problems children and adolescents with Nonverbal Learning Disability experience. To investigate this question, parent responses on the PBS were examined. A Univariate Analysis of Variance (ANOVA) was performed to measure items on the Inappropriate Behavior Scale. The Inappropriate Behavior scale includes a range of items assessing immaturity, poor judgment, lack of appropriate social inhibition, self-injurious behavior, and unusual posturing. An ANOVA was also performed to measure items on the Perseveration scale. The Perseveration scale evaluates the repetitive, inflexible behavior patterns seen in children with brain damage. Neither of these analyses yielded any significant results. However, when the mean T scores were examined for each of these scales, the mean T score for the Inappropriate Social behavior fell in the at-risk range. When each age group was examined individually, results showed that only the “younger” group fell in the atrisk range (M = 64.41, SD = 8.9) for Inappropriate Social behavior (see Table 3). The “older” group did not. Results indicate that children diagnosed with NLD between the ages of 6 and 10, may be more likely to exhibit various inappropriate social behaviors, than older children diagnosed with NLD between the ages of 11 and 16, However, these results should be interpreted with caution given the small sample size. Question 4 The purpose of question four was to determine what psychological disorders commonly occur with NLD. This research question was investigated by documenting the various diagnoses given to participants who were evaluated in the clinic. Percentages are 63 Table 3 Mean T scores for the Inappropriate Social Behavior Scale and the Perseveration Scale PBS Scale Inappropriate Social Behavior Perseveration Note. At-Risk Range = 63-69 Clinical Range = 70-90 Younger M 64.41 62.47 Age Group Younger Older SD M 8.9 62.31 11.79 60.63 Older SD 10 11.17 reported in Table 4. As can be seen in the table, the most commonly occurring comorbid diagnosis is ADHD. Fifty four percent of the sample had a comorbid diagnosis of ADHD. It was noted that almost equal numbers of participants were diagnosed with ADHD within both age groups (“younger” = 18, “older” = 21). Dysnomia and Dyslexia had the next two highest occurrences (19.4% and 12.5% respectively). Lastly, Behavior Disorders and Motor Coordination Delay occurred equally within the sample at 11.1%. As a result of the small sample size, additional statistical analyses were not warranted. However, it was observed that the frequency at which a Motor Coordination Delay occurred in the “younger” group was noticeably larger than the frequency at which a Motor Coordination Delay occurred in the “older” group (Refer to Table 4). Seven participants of thirty eight in the “younger” group were diagnosed with having a Motor Coordination Delay. Only one participant in the “older” group was diagnosed with having a Motor Coordination Delay. According to Davis and Broitman (2011), issues noted with early motor developmental milestones, clumsiness, and difficulties with sports and handwriting would all be moderately consistent with aspects of NLD. 64 Table 4 Percentages of Comorbid Psychiatric Diagnoses in the Total NLD Sample Diagnosis ADHD Dysnomia Dyslexia Behavior Disorder (ODD, CD) Motor Coordination Delay Dyscalculia Disorder of Written Expression Anxiety Dysgraphia Depression Dysphasia Percentage 54.2% 19.4% 12.5% 11.1% 11.1% 9.7% 5.6% 5.6% 2.7% 1.4% 1.4% Young 18 6 3 6 7 3 2 2 1 0 1 Old 21 8 6 2 1 4 2 2 1 1 0 A noticeable difference was also observed between the two age groups regarding a comorbid diagnosis of a Behavior Disorder. Six participants of thirty eight in the “younger” group were diagnosed with a Behavior Disorder (i.e. Oppositional Defiant Disorder, Conduct Disorder). Only two participants in the “older” group were given an additional diagnosis of a Behavior Disorder. Neither of these differences is statistically significant, but may suggest that these developmental delays disappear with age. Supplemental Research Question Of related interest to this investigation is the manner in which the NLD participants compare to a normative sample on specific scales of the PBS. The raw mean scores of the NLD group were compared to a general pediatric patient sample (Lindgren & Koeppl, 1987) on the externalizing and internalizing subscales of the PBS. Raw mean scores were used to make the comparison rather than T scores, because the authors of the PBS only reported raw scores for their normative sample. The pediatric sample consisted 65 of 106 pediatric patients (males = 86, females = 20). Ages of the children ranged from 6 to 16 years (M = 9.74 years, SD = 2.88). The sample consisted of patients with various pediatric disorders including, seizure disorder, specific developmental disorder or learning disability, Attention Deficit Disorder, behavioral/adjustment problems, and somatic complaints. Medical diagnoses in the sample included obesity, diabetes, asthma, neurofibromatosis, cerebral palsy, brain tumor resection, arteriovenous malformation, migraines, cystic fibrosis, short stature, hemophilia, and AIDS. Table 5 provides the descriptive statistics and the test statistic (t) for the current NLD sample and for Lindgren and Koeppl’s (1987) normative sample. Table 5 Descriptive Statistics (Raw Scores) and t scores for PBS Subscales by Group (NLD and Lindgren and Koeppl’s (1987) Normative Sample) Group Variable NLD M 1.36 0.45 1.07 1.79 1.24 0.90 0.68 1.03 1.10 0.34 0.84 Oppositional Behavior Aggression Explosiveness Attention Impulsivity Hyperactivity Tension Anxiety Self Esteem Depression Social Isolation Note. *p < .05 **p < .0045 Bonferroni Correction SD 0.8 0.59 0.81 0.84 0.80 0.84 0.56 0.67 0.83 0.42 0.76 Normative Sample M SD 1.13 0.65 0.36 0.39 0.94 0.79 1.42 0.89 1.07 0.85 1 0.92 0.69 0.68 0.81 0.61 0.88 0.75 0.26 0.33 0.67 0.65 t 2.41* 1.26 1.37 3.71** 1.80 -1.03 -0.17 2.80* 2.27* 1.64 1.93 66 As can be seen in the table, scores for Lindgren and Koeppl’s (1987) normative sample were highest on the Oppositional Behavior, Attention, Impulsivity, and Hyperactivity subscales. Similarly, the NLD sample’s scores are also highest on the Oppositional Behavior, Attention, and Impulsivity subscales, with the addition of the Explosiveness, Anxiety, and Self-Esteem subscales. Both groups presented with the lowest scores on the Aggression and Depression subscales. Thus, results indicated that the NLD sample and Lindgren and Koeppl’s (1987) normative sample exhibited behavior problems and ADHD symptoms comparatively. However, the NLD sample was more likely to demonstrate problems with explosive behaviors, signs of anxiety, and selfesteem problems. One-Sample T-tests were run to test whether the current group differed from the normative group on the externalizing and internalizing behavior subscales. On average, the NLD group exhibited significantly higher scores on the oppositional behavior subscale (M = 1.36, SD = 0.8) than the normative sample (M = 1.13, SD = 0.65), t(71) = 2.41, p < .05. The NLD group also exhibited significantly higher scores on the Attention subscale (M = 1.79, SD = 0.84) than the normative sample (M = 1.42, SD = 0.89), t(71) = 3.71, p < .01. These results indicate that the difference between the two group means is statistically significant. Thus, it is likely that children with NLD will exhibit higher rates of oppositional behavior and attention problems than the pediatric patients in the normative sample. Significant results were also found on the internalized behavior subscales. The NLD group exhibited on average, significantly higher scores on the Anxiety subscale (M = 1.03, SD = 0.67) than the normative sample (M = 0.81, SD = 0.61), t(71) = 2.80, p < .01. The NLD group also exhibited significantly higher scores on the Self-Esteem 67 subscale (M = 1.1, SD = 0.83) than the normative sample (M = 0.88, SD = 0.75), t(71) = 2.27, p < .05. Higher scores on the Self-Esteem scale indicates lower self-esteem. These results suggested that the two group means on the Attention subscale and the two group means on the Self-Esteem subscale differed significantly. Thus, it is likely that children with NLD will demonstrate higher rates of anxiety and lower self-esteem than the pediatric patients in the normative sample. The difference of the two group means on the Social Isolation subscale closely approached significance at p = .057. This result suggested that children with NLD may be at a higher risk for experiencing problems with Social Isolation than the pediatric patients comprising the normative sample. To control the familywise error rate for the set of 11 t-tests, a Bonferroni correction was used. To maintain a familywise Type 1 error rate of .05, the Bonferronicorrected value became .0045. At this more stringent significant threshold, only the Attention subscale remained statistically significant. 68 CHAPTER V DISCUSSION Nonverbal Learning Disability has been reported to create significant social challenges for those children and adolescents whom it affects. Additionally, past research investigations suggest that the combination of these social deficits can lead to failed social interchanges, which in turn, has the potential to lead to severe internalized psychopathology, including anxiety and depression. Even though a lot of disagreement remains regarding the validity of an NLD diagnosis (Davis and Broitman, 2011), it is important that researchers and scientists continue to conduct investigations on NLD because of the potential severe challenges and detrimental social outcomes that may result from it (Little, 1993). Additionally, by having more studies investigating NLD, better interventions can be developed. At present, interventions for NLD include educational modification, occupational therapy, pragmatic language training, and social skills training. These interventions may work for some kids but not all kids effected by NLD. Conducting further research on NLD may generate even more effective programs and treatments for this population. As NLD appears to be a developmental disorder that affects individuals from early childhood into adolescence, the current study aimed to explore the age-related differences between a younger group of children and an older group of children diagnosed with NLD. First, the current findings from this investigation are addressed. Second, general themes from the study are discussed in reference to past age-related research studies in children and adolescents with NLD. Third, limitations of the current 69 study are identified. Lastly, implications for practice are discussed followed by implications and suggestions for future research. The main finding from the current study is that based on parent ratings younger and older children manifest the social, emotional, and behavioral characteristics of NLD in a similar manner. Thus, no age-related differences were found in this study. It should be noted that there were participants whose parents rated them to be in the “atrisk” range for various externalizing behaviors. However, the overall mean did not fall in this range. The lack of statistically significant results could be a result of small sample size. A power analysis conducted at the beginning of this study determined that 171 participants were needed to show any statistically significant differences. The current study only had 72 participants total. Once the total sample was separated into two groups, the numbers became even smaller. Another reason due to the lack of significant findings may be the result of the type of dependent measure that was used. Results from this study were based on parent ratings. In regards to internalized behavior, parent rating scales may not be a true indication of what the child thinks or feels since the ratings are based on observation. Additionally, no significant differences were found regarding social behavior and age. Once again, the lack of statistically significant results could be due to small numbers. However, when the overall mean was calculated for items on the inappropriate behavior scale, the younger groups’ mean T score fell in the at-risk range. Perhaps, with a larger sample, significant results would have been found. Moreover, the Inappropriate Social Behavior scale consisted of only 14 items. A more comprehensive measure of social skills in addition to larger numbers may have yielded different results. 70 Percentages were reported for psychiatric comorbidities. More than half of the sample (54%) had a diagnosis of ADHD. This finding is not surprising as past research studies have reported comorbid diagnoses of NLD and ADHD in their findings (GrossTsur et al., 1995; Semrud-Clikeman, Walkowiak, Wilkinson, and Christopher, 2010). Although no significant age-differences were found in regards to psychiatric comorbid disorders, two results were found that may have clinical significance. First, despite the small numbers, there was a noticeable difference between the numbers of children in the younger group with a Motor Coordination Delay than in the older group. According to Davis & Broitman (2011), issues noted with early motor developmental milestones, clumsiness, and difficulties with sports and handwriting are symptoms of NLD. An additional explanation for this motor delay could be a result of less physical exploration during early development. Rourke (1995) postulated that children with NLD would rather hear about their environment than to see or touch it. Hence, they exhibit little exploratory behavior. Thus, the delay they experience in motor coordination could be attributed to less physical exploration of their surroundings; thereby potentially causing a delay in their gross motor skills. Rourke also hypothesized that their visual-spatial deficits may affect their ability to maneuver around objects in their environment. As a result, these children may appear clumsy and ill-coordinated at times. Since there were no significant differences between age groups, it is quite possible that these developmental delays may disappear with age. There was also a noticeable difference between the numbers of children in the younger group that had a comorbid diagnosis of a behavior disorder (i.e. ODD, CD) than in the older group. Once again, these age-differences were not found to be statistically 71 significant, which may be due to small numbers. However, these results may be clinically significant. Forrest (2004) stated that as a result of a combination of their neuropsychological deficits, children with NLD are frequently perceived as acting out and hyperactive, and are commonly identified by their teachers as over talkative, trouble makers, or behavior problems. The results from this study lend additional support to this claim and may serve as indicators for clinicians. It is not clear whether these behaviors are a result of their NLD diagnosis as Rourke suggests. These behaviors may be a reaction to their environment as in the case example of K. (Panos et al., 2001). Regardless of the etiology, it is important to be aware of how these behavior problems effect the social and emotional development of these children. When raw mean scores were compared between the NLD group and the normative group, which consisted of a general pediatric population, statistically significant group mean differences were found. Results indicated that the NLD group demonstrated significantly higher rates of oppositional behavior, attentional difficulties, self-esteem problems, and anxiety compared to the general pediatric patient sample. Thus, when children and adolescents with NLD were compared to a group of children without NLD, significant differences were observed in various externalizing and internalizing behaviors. Although these scores are statistically significant, they are not clinically significant. When the overall mean was calculated for externalizing and internalizing behaviors for the current NLD sample (both young and old), the mean T score did not reach the “at-risk” range. Thus, there is a significant difference between the rates in which the NLD sample and normative sample manifest these behaviors as rated 72 by their parents. However, the scores themselves do not reach clinical significance (T score above 70). In summary, no age-related statistically significant social, emotional, or behavioral differences were found between the two age groups in the current study. Results indicated that there is no difference in the way younger children and older children with NLD manifest various behaviors. However, these results should be interpreted with caution as the current sample size was low. Additionally, it cannot be stated with certainty whether these results will generalize to the rest of the population because of the low number of participants in the study. Strength and Limitations The main strength of this study is that it used more stringent criteria for inclusion in the NLD group. Instead of the 10 point discrepancy between the VCI and PRI which is commonly used, a 13 point discrepancy was required for inclusion in the NLD group. By using a more stringent criteria, the more confidant the diagnosis of NLD. This is important given that there are no set criteria for NLD. A number of limitations exist in this study. First, the results from this study may not generalize to other child populations with NLD. The participants from this study consisted of children and adolescents from Iowa. The typical population of children in Iowa consists of Caucasian children, and many of the children that are seen in the clinic from which the data was collected, come from rural areas. Thus, it is not likely that the current sample is representative of all children and adolescents with NLD. Second, the sample size was small. Small numbers is something that plagues many researchers that study children with NLD. This may be due to the low prevalence 73 of NLD. Rourke has estimated that only 1% of the population is likely to exhibit NLD. In addition, as mentioned above, sample size was restricted to more conservative criteria for inclusion into the NLD group. Thus, it is possible that the current study loss power as a result of its small sample size, resulting in no statistically significant findings. Third, the current study possessed instrument limitations. Some of the assessment instruments that were used to collect data were somewhat outdated and/ or had insufficient validity. For example, the PBS was normed in the early 80s. These norms have not been updated. Thus, its validity is questionable. It is possible that more current measures with stronger validity would have resulted in statistically significant differences. Implications for Practice The current study has implications for counseling psychologists involved in the assessment and treatment of children and adolescents with possible NLD. Philosophically, counseling psychologists rely on a developmental perspective to focus on strengths and adaptive strategies. Since NLD appears to be a developmental disability, counseling psychologists may want to consider how this disability affects children at various stages. Although no statistically significant age-related differences were found in the current study, this lack of findings does not mean that no significant differences exist. The finding that no statistical differences were found between the two age groups may imply that the characteristics of NLD manifest itself in a similar manner in both groups. This information may aid counseling psychologists in identification of symptoms and diagnosis. Additionally, although neither age group scored in the clinical range for internalizing and externalizing psychopathology, many children were rated by 74 their parents to be within the at-risk range for several of these behaviors. Thus, these atrisk behaviors may serve as potential indicators for clinicians. As previously mentioned, there is no set criterion for NLD. This can be problematic for clinicians working with this population as they routinely rely on symptom characterization to identify disorders. Some researchers have suggested dividing NLD into different subtypes. Utilizing a subtype model may aid counseling psychologists in diagnosis, treatment, and intervention when working with individuals with NLD. As Forrest (2004) suggested, by breaking NLD into subtests, clinicians can focus on the area of greatest functional impairment. Therefore, if deficits in social skills are primary, the clinician can focus on interventions that aid in the development of better social skills. Conversely, if visual-spatial deficits are primary and affecting the child’s academic performance, the clinician may focus more on the implementation of interventions in the school setting. Thus, it may be helpful for counseling psychologists to also consider subtyping when working with this population. Counseling psychologists, as many other health care professionals, are encouraged to keep current about developments in their field by attending various trainings and conferences. Although, a lot remains unknown about NLD, keeping up to date on what is known about NLD may lead to more accurate diagnosis. As mentioned earlier, NLD shares many characteristics with other disorders such as ADHD and AS. Learning more information about how these three disorders differ will ultimately aid in diagnosis. Accurate diagnosis is important because it determines which interventions are implemented. Without the right diagnosis, incorrect services and interventions may be put in place, which can hold a child back from being successful. As mentioned numerous 75 times in this study, children and adolescents with NLD tend to struggle with social interactions. A clinician may read in a school report that a child is having challenges with developing and maintaining friendships and automatically think that the child would benefit from a social skills group. However, if the child is experiencing impairment in social skills as a result of poor visual-spatial skills, a social skills training group will be of little help. Therefore, it is important that clinicians are knowledgeable about NLD to aid in accurate diagnosis. Counseling psychologists should also be aware that NLD tends to be diagnosed later in life. Thus, clinicians assessing this population should watch out for symptoms of comorbid disorders among younger clients. Identifying NLD early on will ultimately lead to early intervention. Early intervention is important because it may improve their success in school and with social relationships. Finally, counseling psychologists who work with children frequently consult with school personnel. Children and adolescents with NLD often present challenges for their teachers (Stewart, 2002). Teachers and other school personnel are put in a difficult position because they may know even less about NLD than clinicians given the low prevalence rate of NLD. If a clinician is well informed about what is known about NLD, s/he can share this information with schools, who can then develop the right educational modifications where appropriate as part of the child’s individual education plan. Implications for Future Research The current study has implications for future research. Counseling psychologists who conduct research aim to have a diverse sample that can be generalized to the population. The current study’s population consisted of children from many rural areas 76 of Iowa. In addition, the sample size was too small. Thus, it is suggested that future researchers aim to have a bigger and more diverse sample size. Additionally, there were some instrument limitations in the current study. If this study were to be replicated, it is suggested that clinicians implement not only more current and valid measures, but also numerous instruments to measure the dependent variables. The current study only used one instrument to measure the behavior, social and emotional characteristics of children and adolescents with NLD. It is possible that having more than one assessment instrument to measure each dependent variable would have yielded different results. Therefore, with replication of this study, it is suggested that numerous instruments are implemented. Specifically, an instrument that solely measures behavior should be used to investigate behavior characteristics. Likewise, an instrument that measures social skills should be utilized to investigate social characteristics. Lastly, rather than using a parent rating scale, researchers may want to include a self-report measure to investigate emotional characteristics and/or internalizing symptoms of psychopathology. In addition to studying age differences amongst children and adolescents with NLD, it is suggested that future research explore social differences based on etiology. As previously mentioned, the features of NLD have been found in individuals with various neurological disorders. Even the current sample included one participant with a diagnosis of Turner’s syndrome and two other participants had a history of seizures. Additionally, the symptoms of NLD have also been known to manifest in individuals after a traumatic brain injury. Given these findings, it is suggested that future research compare the social outcomes of these differing groups of children who manifest NLD 77 [e.g. children in which the symptoms of NLD developed over time vs. children with NLD in which it was acquired (e.g. from a traumatic brain injury) vs. children with genetic disorders]. Finally, it is suggested that future research include neuroimaging as one of the instruments/techniques for investigating the syndrome of NLD as was illustrated in the case of K. (Panos et al., 2001). NLD has been hypothesized as occurring as the result of a dysfunctional right hemisphere, dysfunctional white matter tracts in the brain, and as a result in the dysfunction of the frontal lobe. Given that NLD appears to be a neurobehavioral disorder, the next logical step in research is to investigate the structure of the brain in children and adolescents that present with the symptoms of NLD. Having images to support these theories may aid in confirming the etiology of NLD. Conclusion Three main findings resulted from this exploratory study. First, results indicate that children and adolescents with NLD may manifest the behavioral, emotional, and social characteristics of NLD in a similar manner. Second, results from this study provide empirical support for the co-occurrence of various psychiatric comorbidities in children and adolescents with NLD, especially ADHD. Third, results from this study indicate that children and adolescents with NLD demonstrate significantly higher rates of oppositional behavior, attentional difficulties, self-esteem problems, and anxiety compared to a general pediatric patient sample. In summary, a lot of disagreement remains regarding NLD as a result of mixed findings and its overlap of features with other developmental disorders. Despite the controversy surrounding the notion of NLD, it is important to conduct NLD 78 investigations as many of the children who manifest its symptoms present with numerous challenges. The creation of subtypes for NLD may aid clinicians in working with this population as it may help them focus on what is primary or causing the greatest amount of concern. In addition to creating subtypes, neuroimaging appears to be another direction for future research. 79 APPENDIX A ROURKE’S NLD MODEL 80 Primary Neuropsychological Assets Auditory Perception Simple Motor Rote Material Primary Neuropsychological Deficits Tactile Perception Visual Perception Complex Psychomotor Novel Material Secondary Secondary Neuropsychological Neuropsychological Assets Deficits Auditory Attention Tactile Attention Verbal Attention Visual Attention Exploratory Behavior Behavio Tertiary Tertiary Neuropsychological Neuropsychological Assets Deficits Auditory Memory Tactile Memory Verbal Memory Visual Memory Concept Formation Problem Solving Verbal Verbal Neuropsychological Neuropsychological Assets Deficits Phonology Oral-Motor Oral Praxis Verbal Reception Prosody Verbal Repetition Phonology>Semantics Verbal Storage Content Verbal Associations Pragmatics Verbal Output (Volume) Function Academic Assets Academic Deficits Graphomotor (Late) Graphomotor (Early) Word Decoding Spelling Verbatim Memory Reading Comprehension Mechanical Arithmetic Mathematics Science Psychosocial Assets Psychosocial Deficits Adaptation to Novelty ??? Social Competence Emotional Stability Activity Level 81 APPENDIX B NLD CLASSIFICATION CRITERIA 82 1. Bilateral tactile perceptual deficits - Performance on measures of finger agnosia, dysgraphesthesia, or astereognosis was 1 SD or more below the norm. 2. Bilateral psychomotor deficiencies - Performance on GPT was 1 SD or more below the mean. 3. Visuospatial/ organizational deficiencies - Performance on the Target Test was 1 SD or more below the norm and Verbal IQ > Performance IQ by 10 or more standard score points. 4. Good verbal capacities - Verbal IQ > 79 and performance on either the SSPT or the Auditory Closure Test no less than, or equal to, 1 SD below the norm. 5. Mechanical arithmetic deficiencies - Performances on the WRAT Reading and Spelling subtests exceeded that of the WRAT Arithmetic subtest by 10 or more standard points.1 1 (Casey et al., 1991) 83 APPENDIX C CLASSIFICATION RULES FOR NLD 84 1. Target Test at least 1 SD below the mean 2. Less than two errors on simple tactile perception and suppression vs. finger agnosia, finger dysgraphesthesia, and astereognosis composite greater than 1 SD below the mean 3. Two of WISC/ WISC – R Vocabulary, Similarities, and Information are highest of the Verbal scale 4. Two of WISSC/ WISC – R Block Design, Object Assembly, and Coding subtests are the lowest of the Performance Scale. 5. WRAT/ WRAT – R standard score for Reading is at least 8 points greater than Arithmetic 6. Tactual Performance Test, Left, and Both hand times become progressively worse vis-à-vis the norms 7. Grip strength within 1 SD of the mean or above vs. GPT greater than 1 SD below the mean 8. WISC/ WISC – R VIQ > PIQ by at least 10 points Note. (1) It should be clear that not all of these are mutually exclusive. (2) For experimental purposes, Pelletier et al. (2001) proposed the following criteria: The first 5 features: Definite NLD 7 or 8 of these features: Definite NLD 5 or 6 of these features: Probable NLD 3 or 4 of these features: Questionable NLD 1 or 2 of these features: Low Probability of NLD2 2 (Pelleteir et al., 2001) 85 APPENDIX D PEDIATRIC BEHAVIOR SCALE FACTORS 86 Pediatric Behavior Scale Factors Specific Scales Oppositional Behavior Aggression Explosiveness Item Numbers 1 to 4 5 to 12 13 to 18 Attention Deficits (AD) Attention Impulsivity Hyperactivity 19 to 23 24 to 28 29 to 33 Depression-Anxiety (DA) Tension Anxiety Self-Esteem Depression Social Isolation 34 to 37 38 to 45 46 to 50 51 to 56 57 to 62 Deviation (DV) Inappropriate Social Behavior Perseveration Variability Thought Disorder 63 to 76 77 to 81 82 to 85 86 to 90 Health (HL) Arousal Coordination Eating Sleeping Physical Problems Medical Noncompliance 91 to 95 96 to 101 102 to 108 109 to 116 117 to 140 141 to 147 Cognition (CN) Expression Comprehension School Problems 148 to 153 154 to 158 159 to 165 General Factors Conduct (CD) 87 APPENDIX E PEDIATRIC BEHAVIOR SCALE 88 89 90 91 92 REFERENCES Achenbach, T. 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