Autism : Assessment of Cognitive Function
Parents and schools need to be aware that standard IQ and other assessments of the cognitive function or mental processing of children with autism, PDD or Aspergers Syndrome may provide inaccurate results.
By David A. Sherman, Special Education Attorney and author of Autism: Asserting Your Child's Right to a Special Education
Assessing the child with autism, PDD or Aspergers Syndrome using standardized instruments has been criticized from a number of perspectives. Many tests have not been proven reliable or valid with special populations and modifications of the instrument are often required to accommodate the child, which may alter the reliability and validity of the instrument. If the child has difficulties in language comprehension, compliance or cooperation, these difficulties may interfere with measuring the cognitive abilities the assessors are targeting. The measurement of intelligence is complex, thus requires innovative interpretation and careful examination. The clinical judgment of a highly skilled psychologist or neuropsychologist may be required.
Many children with autism, PDD or Aspergers Syndrome posses a wide spectrum of strengths and weaknesses. Some children are cognitively impaired as a component of their autism, but practitioners and parents should not readily assume severe impairment without substantial confirmation.
Over a decade ago, noted researcher and autism expert Dr. Stanley Greenspan challenged the widely accepted statistic that 70-80% of children with autism, PDD or Aspergers Syndrome also have mental retardation. He charged that standardized instruments did not adequately account for learning differences, such as auditory processing and motor planning, arguing that the reported numbers were arrived at erroneously. Perceptual-motor skills are delayed for many children on the spectrum, however visual-motor skills tend to e enhanced when the visual stimuli remains constant throughout the task, resulting in a accumulated IQ score that is only marginally relevant to instruction and intervention (Greenspan, Weider & Simons, 1998). By way of analogy, if a hearing or visually impaired child's hearing aid or glasses were removed and standard intelligence tests were administered, the resulting scores would be misleading low. Auditory an visual processing, while a component of intelligence, should not obstruct measuring cognitive skills. Assessing cognitive functioning in a child with autism, PDD or Aspergers Syndrome is an extremely complex process.
Recent research shows that reported associations of mental retardation in individuals with autism may actually be much lower than previously believed (Lord & Volkmar, 2002; M.I.N.D. Institute Report, 2002). Yet most professional and popular literature does not reflect this research, resulting in a discrepancy that is pervasive in its influence on both parents' and professionals' position about a child's potential.
While it is possible for a child to have both autism and mental retardation ,this should not be assumed. Some children have been inaccurately assessed as mentally retarded because assessors were not skilled and experienced in autistic spectrum disorders, or because the assessor's training predisposed them to expect that the majority of their subjects would be mentally retarded.
Parents should not be discouraged from allowing their child to be tested. Schools have a legal right, and in fact a legal responsibility, to offer an assessment. While some parents would rather not allow schools to evaluate their child, a refusal to cooperate at certain stages in the process can backfire if the parents need to ask for more or for different services later, or if parents wish to have the school system pay for an independent educational evaluation. Some parents refuse all psycho-educational testing. It is not wise to disallow testing based on the difficulties involved. Rather, parents must seek out professionals who are trained and experienced in assessing children with autism, PDD or Aspergers Syndrome, whose professional skills are current, who can be objective and who involve parents in the assessment process.