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Clinical Neuropsychology
Clinical neuropsychologists perform assessments and design interventions for persons
who experience neuropsychological dysfunction because of brain injury or illness. They also
conduct research on both normal and abnormal brain functioning that has helped to shed light
on psychological disorders such as depression and schizophrenia.
Clinical neuropsychology is a relatively new and growing field, and its practitioners must
understand brain-behavior relationships and be trained in a variety of assessment and
intervention techniques unique to the field.
Neuropsychology is the field of study that seeks to understand how brain processes
make human behavior and psychological functions possible. Neuropsychologists are interested
in a wide range of human abilities, including aspects of cognitive functioning (e.g., language,
memory attention, mathematical, and visuospatial skills), motor functioning (e.g., learned
skilled movements, gross and fine motor skills), emotional functioning (e.g., motivation,
understanding and expressing emotion, anxiety, depression, euphoria), social functioning (e.g.,
prejudice, social judgment, interpreting social information), and personality traits (e.g.,
extraversion, neuroticism).
Neuropsychologists study how brain operations control such processes and how this
control breaks down after brain dysfunction (e.g., stroke, infection, neurodegeneration) or
psychological disorders (e.g., posttraumatic stress disorder, clinical depression, schizophrenia).
Clinical neuropsychologists become involved in the psychological and behavioral
evaluation of individuals. By doing careful testing of a person’s psychological functions;
 They can learn whether or not the person shows a pattern of impairments
suggestive of brain damage, and if so, to what brain regions.
 They can also help quantify the severity of psychological deficits.
 They help clarify how a person’s problem from brain damage are likely to affect that
particular individual’s ability to function socially, vocationally, and in other aspects
of daily living.
 Finally, they can help formulate a regimen for rehabilitation and recovery from the
effects of brain damage.
Clinical neuropsychologists must use several kinds of knowledge and skills in their work.
1. They make use of the assessment skills.
2. They must be able to use specialized assessment methods unique to
neuropsychological assessment.
3. Clinical neuropsychologists must have the knowledge of neurosciences, including
neuroanatomy (the study of nervous system structures and the connections
between them), neurophysiology (the study of the functioning of the nervous
system and its parts), and neuropharmacology (the study of how drugs affect
nervous system functioning).
4. They must know about a wide range of human cognitive abilities, including language
and perception.
5. They must be able to distinguish behavioral and psychological problems caused by
brain dysfunction.
6. Finally, they must be able to design effective rehabilitative programs based on an indepth understanding of clinical psychology.
Development of Neuropsychological Assessment Techniques
As part of their evaluation of people, clinical neuropsychologists use standardized tests that
assess separate aspects of psychological function. Tests of Alfred Binet are usually associated
with the beginning of modern intelligence testing, but they also laid the foundation for
neuropsychological assessment. Many of the disorders commonly assessed today with
neuropsychological techniques had been identified by Binet’s time. These included aphasia
(disordered language abilities), apraxia (impaired abilities to carry out learned purposeful
movements), agnosia (disorders of perceptual recognition), and amnesia (disorders of
memory). In Russia, the psycho neurological Institute was formed in 1907 to study the
behavioral effects of brain damage, and throughout the first decade of the 1900s, several
people in the United States were using psychological tests to study how brain damage affects
behavior.
One of these people was Ward Halstead, who in 1935 founded a neuropsychology
laboratory at the University of Chicago. His major contribution was to observe persons with
brain damage in natural settings. Halstead’s first graduate student, Ralph M. Reitan, started a
neuropsychology laboratory in 1951 at the Indiana University Medical Center. Reitan revised
Halstead’s test battery and included the Wechsler Intelligence Scale and the Minnesota
Multiphasic Personality Inventory (MMPI) in what came to be known as the Halstead-Reitan
Battery (HRB). This battery is still widely used today.
Split-Brain Research
Another important chapter in the history of neuropsychology is associated with the
work of Roger Sperry and his colleagues at the California Institute of Technology. They studied
the psychological effects of cutting the corpus callosum, the band of nerve pathways that the
brain’s two hemispheres rely on to communicate directly with each other. This surgical
procedure is performed in the hope that it will prevent the spread of epileptic seizures from
one side of the brain to the other in certain cases where drug treatment fails. With the corpus
callosum severed, there is no direct pathway between the hemispheres, so the activity of one
cerebral hemisphere proceeds largely isolated from that of the other hemisphere.
Research on Normal Brains
Split-brain research, and the innovative testing techniques involved in it, stimulated an
increase in studies of the organization of normal brains. Many of these studies used a
tachistoscope, a device that displays visual stimuli for a very brief period of time. When the
eyes are fixated on a central point in the visual field, stimuli briefly flashed to the left of the
fixation point are seen only in the left visual field. Similarly, stimuli briefly flashed to the right of
the fixation point appear only in the right visual field. Because of the way the eyes are “wired”
to the brain, information from the left side of space is sent first to the right cerebral
hemisphere and information from the right side goes first to the left hemisphere. The
information from each side of space is then normally shared between hemispheres via their
connections through the pathways provided by the corpus callosum.
Basic Principles of Neuropsychology
Certain principles of brain behavior relationships are fundamental to neuropsychology.
Localization of Function
The idea that specific parts of the brain are involved in specific behaviors and
psychological function became the prevailing view of scientists by the end of the 19th century
(Tyler and Malessa, 2000), and this localizationist view is now widely accepted.
Theorists who emphasize the interrelatedness of brain areas and who stress the holistic
quality of brain functioning are sometimes known as globalists.
John Hughlings Jackson Alexander Luria who more than any other scientist, proposed a
theory of organization that emphasized its integration rather than its specificity (Glozman,
2007).
Luria’s theory was the brain is organized into three functional systems:
(a) A brain stem system for regulating a person’s overall tone or waking state;
(b) A system located in the posterior (back) portion of the cortex for obtaining, processing
and storing information received from the outside world; and
(c) A system, located mainly in the anterior (front) portion of the cortex, for planning,
regulating, and verifying mental operations.
Modularity
Today, when neuropsychologists map the brain according to specific functions, they do
so in a way that reflects both localizationist and globalist perspectives.
Different brain areas are thus seen as different information processing modules,
something like the many different circuit boards contained in a vast, complex computer.
According to the modular view, then a complicated psychological function such as attention is
not “controlled” by the single brain area.
Levels of Interaction
Different modules interact with the each other to produce a seamless sequence of
behaviors. The modules are organized in a fashion that reflects both the structure and function
of the brain. Thus, the brain can be seen as having several levels of organization, ranging from
the global to the local.
Lateralization of Function
As noted earlier, the cerebral cortex is divided into two hemispheres. The activity of
each hemisphere is associated with somewhat different functions. At one time, this difference
was described in terms of “cerebral dominance” because the left hemisphere was seen as
“dominant” or “major” one and the right as the “nondominant” or “minor” hemisphere.
Specialization of the Left Hemisphere – in the most right – handed people, the left
hemisphere is specialized to handle speech and other aspects of linguistic processing such as
the ability to understand what other say. The ability to speak is very strongly left lateralized in
the most right – handed people so that the right hemisphere has little or no direct access to
speech mechanisms.
Specialization of the Right Hemisphere – right hemisphere function, too, plays an
important role in language and communication, thought it usually lacks direct access to the
systems that allow people to speak.
People with right hemisphere damage also have difficulty understanding linguistic
devices such as metaphors. So they might interpret statements like “I cried my eyes out” as if
they were literally true.
Aprosodia – an interruption in normal prosody functions, occurs after right hemisphere
damage more often than after left hemisphere damage. A person with expressive aprosodia
speaks in a monotone and sometimes must add a phrase such as “I am angry” to allow the
listener to understand the intended emotional message.
The difficulties patients with right brain damage have in judging situations
appropriately, in relating to others, and in accurately perceiving social cues is compounded by
another problem – they are often unaware of their deficits.
Pattern of Neuropsychological Dysfunction
Occipital Lobe Dysfunction
Visual information is sent from the retina in each eye to the thalamus and then to the
occipital lobes of the cerebral cortex. At each step along the way, this information is
represented topographically; in other words, neighboring nerve cells response to neighboring
areas of the visual field.
The most common problem caused by damage to the occipital lobe is blindness.
Because about half of the retinal fibers coming from each eye cross over to the opposite side as
they enter the brain, damage to one occipital lobe produces blindness in the opposite visual
field.
Parietal Lobe Dysfunction
Parietal association cortex is thus a meeting ground for visual, auditory, and sensory
input, making it vital for creating a unified perception of the world. In particular areas of the
parietal lobes help create a map of our environment and the objectives in it: they also perform
an ongoing analysis of where objects are side of the body and the side of space opposite the
damaged hemisphere.
One way in which clinical neuropsychologists test for hemineglect is to ask a patient to
draw a clock or a flower. People with hemineglect may draw all the numbers on the clock or all
details of the flower, on one half of the paper and leave the other half blank.
Another possible consequence of parietal lobe dysfunction, especially on the right side
of the brain, is simultanagnosia.
Temporal Lobe Dysfunction
While incoming visual information being integrated in the parietal lobes, that same
information is also being analyze in cortical areas of the temporal lobe.
So when people with this problem, called visual agnosia, look at an apple, they might
describe it as “a round smooth spherical object with a thin protrusion at the top” but be unable
to name it, say what it is used for, where it can found and so on.
Frontal Lobe Dysfunction
Many areas in the brain’s frontal lobes are involved in planning behavior. This kind of
activity is sometimes called the executive function of the brain, because, like the work of a
corporate executive, it entails organizing, supervising, sorting, strategizing, anticipating,
planning, making judgments and decisions, engaging in self – regulation, assimilating new
information, adapting to novel situations, and taking purposeful action.
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Dysfunction
Prominent Symptoms
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Aphasia
disordered language abilities
Apraxia
impaired abilities to carry out learned purposeful movements
Agnosia
disorders of perceptual recognition
Prosopagnosia
inability to recognize faces
Amnesia
disorders of memory
Aprosodia
an interruption in normal prosody (tone of voice) functions
Anosognosia
inability to be aware of neurological problems
Hemineglect
ignoring the side of the body and the side of space opposite the damaged
hemisphere
Echolalia
repeating the words someone else has just said
Akinetic mutism
never moving or speaking
Blindsight
having no conscious awareness of seeing and yet responding to moving
stimuli as if it were seen
Simultanagnosia
ability to see but difficulty grouping seen items together in space
Neuropsychological Assessment
Assessment is designed to establish the nature and severity of a patient’s deficits,
determine the likelihood that the deficit stem from brain damage, provide an educated guess
as to where the damage might be located, and identify the particular disease or the kind of
damage responsible for the particular pattern of deficits seen.
Clinical neuropsychologists’ efforts to identify the symptoms and locations of brain
damage and to plan rehabilitative interventions always begin with assessment. It can involve
standardized batteries or individual tests specifically selected for individual patients. Because
clinical neuropsychologist often work with physicians.
Clinical Neuropsychologist typically follows one of two approaches to assessment. The
first is to use a predetermined, standardized battery tests with all patients. The second
approach to neuropsychological assessment is the individualized method in which an opening
round of tests routinely given to every patient, but the choice of other test is based on the
results of the first set and tailored to answer the specific diagnostic questions of greatest
interest.
Neuropsychological assessment
Assess the extent of impairment to a particular skill and to attempt to locate an area of
the brain which may have been damaged after brain injury or neurological illness
The Halstead-Reitan Neuropsychological Test Battery
is a fixed set of eight tests used to evaluate brain and nervous system functioning in
individuals aged 15 years and older. Children's versions are the Halstead Neuropsychological
Test Battery for Older Children (ages nine to 14) and the Reitan Indiana Neuropsychological
Test Battery (ages five to eight).
Discovered by Ward Halstead and Ralph Reitan are the developers of the Halstead-Reitan
battery
Purpose
Neuropsychological functioning refers to the ability of the nervous system and brain to process
and interpret information received through the senses. The Halstead-Reitan evaluates a wide
range of nervous system and brain functions, including: visual, auditory, and tactual input;
verbal communication; spatial and sequential perception; the ability to analyze information,
form mental concepts, and make judgments; motor output; and attention, concentration, and
memory.
The Halstead-Reitan is typically used to evaluate individuals with suspected brain damage. The
battery also provides useful information regarding the cause of damage (for example, closed
head injury, alcohol abuse, Alzheimer's disorder, stroke ), which part of the brain was damaged,
whether the damage occurred during childhood development, and whether the damage is
getting worse, staying the same, or getting better. Information regarding the severity of
impairment and areas of personal strengths can be used to develop plans for rehabilitation or
care.
THE HALSTEAD-REITAN NEOROLOGICAL TEST BATTERY
TEST NAMES
Category Test
A total of 208 pictures consisting of geometric figures are presented. For each picture,
individuals are asked to decide whether they are reminded of the number 1, 2, 3, or 4. They
press a key that corresponds to their number of choice. If they chose correctly, a chime sounds.
If they chose incorrectly, a buzzer sounds. The pictures are presented in seven subtests.
Tactual Performance Test
A form board containing ten cut-out shapes, and ten wooden blocks matching those shapes are
placed in front of a blindfolded individual. Individuals are then instructed to use only their
dominant hand to place the blocks in their appropriate space on the form board. The same
procedure is repeated using only the non-dominant hand, and then using both hands. Finally,
the form board and blocks are removed, followed by the blindfold. From memory, the
individual is asked to draw the form board and the shapes in their proper locations. The test
usually takes anywhere from 15 to 50 minutes to complete. There is a time limit of 15 minutes
for each trial, or each performance segment.
Depression
Neuropsychologist have been interested in depression ever since Guido Gainotti (1972)
Documented in a systematic fashion that localized brain damage can produce emotional
effects. These studies have also shown that the probability of depression rises with increasing
proximity of the lesion to the front part of the brain. The closer the lesion is to the frontal pole
of the left hemisphere, the more severe the depression. The left hemisphere in people who are
clinically depressed is typically less active than the right; similarly, when people who are not
clinically depressed are feeling sad, the left hemisphere is less active than the right hemisphere.
These differences in brain activity are most evident over the frontal regions of the brain,
confirming their importance for these emotional effects.
Tachistoscopic studies have also shown that when visual stimuli are projected to both
hemispheres, the left hemisphere typically rates pictures as more positive than the right
hemisphere
Other studies have found that depression is associated with decrease in right posterior activity.
People who are depressed show some of the same cognitive deficits displayed by patients with
damage to parietal-temporal regions of the brain. They have difficulty with visuospatial
information processing and show a number of attentional problems that are similar to patients
with right-brain damage. These effects may be caused by the interrelationship of the frontal
and posterior regions of the brain. Because frontal regions often inhibit activation in posterior
regions, relatively greater activation in the right frontal region compared to the left maybe
producing too much inhibition of the right posterior regions.
Schizophrenia
Neuropsychologists have been deeply involved in studying brain functioning in people with
schizophrenia. Early studies, most of which used tachistoscopic methods, suggested the
possibility that schizophrenia in characterized by an overactivation of the brain’s left
hemisphere.
Negative symptoms
(Structural lesions to prefrontal region)
Involving reductions in normal functioning
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Lack of initiative
Lack of energy
Absence of social engagement
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Loss of spontaneity
Positive symptoms
(Damage part specialized regions of the left hemisphere)
Problematic additions to mental life
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Nonlinear reasoning
Delusions
Hallucinations
Intrusions into working memory
Neogalism
Rhyming speech
Odd language utterances
Learning disabilities
Neuropsychologists are very interested in cognitive abilities. Many of them focus their research,
assessment, and intervention efforts on learning disabilities. Much of their work focuses on the
role of behavioral, environment and social factors in these disorders but they have discovered
some fascinating biological correlates, too. Several neuropsychological studies have found, for
example that development of dyslexia is usually related to dysfunction of the left hemisphere.
People who are known to have had dyslexia also show that structure of their left hemisphere
differs from that of people without dyslexia.
Nonverbal Learning Disabilities
A different type of learning disability involves deficits in visuospatial and visuomotor skills, as
well as in other abilities that depend on the right hemisphere. They are slow to learn such as
skills as;
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tying shoes,
dressing,
eating,
and organizing time and their environment
Nonverbal learning disabilities may result from right-hemisphere deficits early
childhood, which can dramatically interfere with normal development
Their lack of experience and interaction with other children can cause them to feel isolated,
lonely and depressed. These factors may be a risk for development of schizophrenia