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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
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