Neuropsychological Aspects of Learning Disabilities

1
Neuropsychological Aspects of Learning
Disabilities

• Margaret Semrud-Clikeman, Ph.D.
• University of Texas at Austin

Responsiveness-to-Intervention Symposium December
4-5, 2003 Kansas City, Missouri The National
Research Center on Learning Disabilities, a
collaborative project of staff at Vanderbilt
University and the University of Kansas,
sponsored this two-day symposium focusing on
responsiveness-to-intervention (RTI) issues. The
symposium was made possible by the support of the
U.S. Department of Education Office of Special
Education Programs. Renee Bradley, Project
Officer. Opinions expressed herein are those of
the authors and do not necessarily represent the
position of the U.S. Department of
Education. When citing materials presented
during the symposium, please use the following
Semrud-Clikeman, M. (2003, December).
Neuropsychological aspects of learning
disabilities. Paper presented at the National
Research Center on Learning Disabilities
Responsiveness-to-Intervention Symposium, Kansas
City, MO.
2
Definitions of LD

• Minimal brain dysfunction
• Word Blindness
• Dyslexia
• Learning disabilities
• Popular after P.L. 94-142
• Suggested include
• Intrinsic to individual
• Due to central nervous system dysfunction

3
Learning disabilities

• Include difficulty with mathematics, written
  language, expressive/receptive language,
  listening comprehension
• The brain naturally learns language
• The child must be taught reading--it is not a
  natural skill.

4
Comorbidity Issues

• Reading disabilities comorbid with ADHD in 20-50
  of the LD population
• We found comorbidity between mathematics and ADHD
  in approximately 30 of the LD population and 75
  of the ADHD population

5
Comorbidity Issues

• Also found a significant overlap between
  difficulties with written language expression and
  ADHD
• Problems with planning and organization of
  written material was found to be more predictive
  of difficulty for these children than reading
  deficits.

6
Brain Imaging and LD

• Information processed differently for children
  with LD
• Fluent adult readers utilize the frontal region
  more than beginning readers
• The left frontal region becomes more active over
  development
• Fluent child readers utilize this area more than
  nonfluent readers.

7
Brain Imaging and LD

• Nonfluent readers show more activity in the
  parietal and occipital regions
• Also more activity noted in the right hemisphere
  for nonfluent readers
• Fluent and adult readers utilize the left
  hemisphere more for reading.

8
Brain Imaging and LD

• There is a change from posterior systems in early
  reading (visual-perceptual processes) to frontal
  systems
• The progression from simple letter and word
  calling to comprehension requires the maturation
  of these pathways from back to front.

9
Brain Imaging and LD

• As child improves in reading, the activation
  changes from diffuse to more organized.
• This change has been found with improvements in
  reading and language skills as well as better
  auditory processing ability.

10
Neuropsychology and LD

• The most predictive measures for response to
  intervention have been found to be attentional
  ability, language processing, and auditory
  processing.
• These skills have been found to be more important
  that verbal IQ or the verbal IQ achievement
  discrepancy.

11
Neuropsychological Components in LD

• Additional evaluation of the following abilities
  is strongly recommended in children with learning
  problems
• Auditory processing/phonemic awareness Attention
• Working memory
• Executive functions (metacognition)
• Processing speed

12
Auditory Processing

• Requires
• the ability to discriminate sounds
• To segment words into sounds
• To produce rhyming words
• Looks at not just the ability to hear individual
  sounds but to supply missing sounds to incomplete
  words

13
Speed of Information Processing

• This skill has been found to be related to
  ability as well as to learning skills
• The rate of decoding of words is more predictive
  of learning problems in older children than the
  ability to decode words
• Reading that is effortful is generally not
  fluent.
• Children who are slower at naming words and
  nonwords showed poorer reading ability.

14
Listening Comprehension

• Is mediated by the same cognitive processes are
  reading comprehension only through the auditory
  modality
• Is a direct measure of the childs ability to
  understand and process language
• Assists with determining whether the reading
  difficulty is due to decoding or comprehension
  deficits

15
Working Memory

• Is the ability to hold information in mind while
  performing a mental operation
• Appears important in the ability to hold sounds
  and words in mind as well as content while
  reading a passage.

16
Working Memory

• Also been linked to the ability to organize a
  tasks temporal aspect.
• The prefrontal cortex is linked to memory systems
  that allow the child to access previously learned
  material
• Difficulties are related to problems with
  decoding and math facts and processing becomes
  effortful and slow.

17
Executive Functions

• Are the how something is accomplished not just
  the what
• Important for the child to evaluate his/her
  performance and to self-correct
• Involved with the ability to inhibit responding
  to irrelevant material.
• Help select what is important to remember or to
  encode

18
Executive Functions

• Anterior Cingulate has been hypothesized to be
  part of an attentional executive system
• Coordinates activity across attentional systems
• Interactions with prefrontal areas may enlist
  support of working memory networks

19
Executive Functions

• When children are directly taught to evaluate
  their progress, their performance improves.
• Worked with 36 children in 3-5 grade who were
  experiencing difficulty with work completion.
• Small group sessions were used to teach
  metacognitive techniques.

20
Executive Functions

• Improvement noted in work completion as well as
  accuracy
• Children were identified as having attentional
  difficulties but not as LD or ADHD.
• Use of frequent feedback, individualized programs
  and support assisted child.

21
Attention

• Everyone knows what attention is. It is the
  taking possession of the mind, in clear and vivid
  form, of one out of what seem several
  simultaneously possible objects or trains of
  thought. Focalization, concentration of
  consciousness are of its essence. It implies
  withdrawal from some things in order to deal
  effectively with others (Wm. James)

22
Attention

• In order for something to be learned, it has to
  be attended.
• Attention has been found to play an important
  role in reading and reading comprehension
• Children with ADHD tend to have more difficulty
  with comprehension than with decoding.

23
Remediation

• Definitional difficulties make it problematic to
  study children with LD across locations
• Neurologically the child lays down neural
  connections that once formed may be difficult to
  reteach.
• May be windows of time when child is most
  receptive to remediation.

24
Shaywitz studies

• Found that poor readers who compensated for
  difficulties through remediation used different
  brain areas than those who did not compensate.
• The main difference was in verbal ability
  (language) and the school level of advantage.

25
What happens if delay services?

• When children were provided with the usual
  interventions, little improvement was seen.
• Assessment is needed prior to the child
  progressing to the third tier.
• Understanding of neuropsychological processes in
  reading (and math) is important in the
  screening done in the first two tiers.

26
Screening

• The development of appropriate screening
  instruments is crucial
• Need to incorporate measures of speed of
  information processing, working memory, and
  attention as well as the mechanics of reading.
• Training for such assessment is crucial

27
Where do we go now?

• University teacher training programs need to
• Provide training in brain processes underlying
  reading skills
• Provide training in evaluation of these skills
• Provide training in appropriate interventions
  beyond the usual practice

28
Conclusions

• Exciting time for learning and teaching
• However, must provide needed support to these
  teachers if the tier system to work
• Need Master teachers and psychologists to provide
  additional support and to consult when a child is
  not responding

29
Conclusions

• Must provide appropriate training at the
  university and practicum levels.
• Continued research is needed as to the
  appropriateness of various techniques to
  individual problems
• Also need continuing research into the long-term
  effects of intervention as well as early
  identification.

30
Finally

• Learning to read is hard work--for dyslexics is
  very hard work
• For teachers of children with learning problems,
  instruction is very hard work. More support is
  needed for these teachers in order for success to
  be realized
• (Berninger, 2003)