The structure of intelligence in children and adults with high functioning autism.

Abstract

Confirmatory factor analyses of the traditional 11 subtests of the Wechsler child and adult intelligence scales were accomplished for 137 children and 118 adults with high functioning autism (HFA) and for comparable age groups from the standardization samples contained in the Wechsler manuals. The objective was determining whether HFA groups produced similar best fitting models to those found in the normative samples or formed a separate "social intelligence" factor. Four-factor models incorporating a "social intelligence" factor provided the best fit in both the autism and normative, but the subtest intercorrelations were generally lower in the autism samples. Findings were interpreted in terms of underconnectivity or reduced communication among brain regions in autism.The Wechsler intelligence scales (Wechsler, 1974;1981;1991) have had widespread application in the assessment of children and adults with autism. Aside from the traditional role of these procedures in educational, vocational, and clinical diagnostic applications, they have been used in autism research to separate high functioning from low functioning autism, for differential diagnostic purposes within the autism spectrum and, perhaps most significantly, for delineating the pattern of cognitive function in autism. The Wechsler contains 11 or more subtests depending upon the version used, making it possible to obtain a cognitive profile of diverse abilities in addition to the Verbal, Performance, and Full Scale IQ scores. A profile apparently unique to high functioning autism has been identified in numerous studies, characterized by relatively high scores on the Block Design subtest and relatively low scores on Comprehension (Rumsey, 1992;Siegel, Minshew & Goldstein, 1996;Yirmiya & Sigman, 1991 NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript subtest scores in autism conducted since 1965since , Siegel et al. (1996 observed that all fourteen reported the Block Design subtest to be the highest Performance subtest, while Comprehension was the lowest Verbal subtest in thirteen of the studies. The consistency of these findings across studies is quite remarkable, given the differences in data analytic and research design methodologies across studies and sites, as well as the various versions of the Wechsler scales used. The Block Design subtest was of particular interest because, often enough, it was not only normal but in the superior range, suggesting the presence of an exceptional spatial constructional ability in some individuals with high functioning autism.In addition to the subtest profile and IQ scores, the Wechsler scales have been repeatedly factor analyzed in both normal and clinical populations. Exploratory factor analysis has generally demonstrated that when the 11 subtest versions of these scales are studied, a threefactor solution is consistently found. More recent applications of factor analysis have employed confirmatory approaches, made possible by advances in structural equation modeling (Jorskog, 197...

Brief Report: Information Processing Speed is Intact in Autism but not Correlated with Measured Intelligence

“…What underlies this atypical cognitive profile remains unknown, but it may reflect reduced neural connectivity, idiosyncratic relationships between cognitive modules, specific cognitive deficits, such as theory of mind difficulties, and/or poor social learning. Nevertheless, individuals with autism demonstrate the dissociability of subtest performance purportedly underlying a general IQ factor and at least one large factor analytic study demonstrates weaker than expected relationships among IQ subtests for children and adults with high functioning autism (Goldstein et al 2008). Moreover, among developmental disorders, autism spectrum disorders (ASD) are particularly associated with savant skills (Heaton and Wallace 2004;Treffert and Wallace 2002) that are often far out of line with measured IQ.…”

Normative sample of the PEAK relational training system: Direct training module and subsequent comparisons to individuals with autism

“…Altogether, 2200 participants comprised the normative sample to ensure that the standardization was based on a representative sample (Wechsler, 2003). By allowing for a frame of reference, the WISC-IV normative sample now allows for differential diagnoses and treatment decisions to be made based on the degree to which children deviate from typically developing children of the same age (Goldstein et al, 2008), and for monitoring relative progress (Koegel, Koegel, & Smith, 1997). From a behavioral approach to language development, the ABLLS and the VB-MAPP have also provided samples of normative data.…”

Relations between learning potential, cognitive and interpersonal skills in Asperger children

“…Although tentatively, it might be thought that related with the results reported by Goldstein et al (2008) and Brock et al (2008) there are fewer interfactor correlations in the non-learner group which might be seen as an indicator of more modular intelligence. Likewise, Aljunied and Frederickson (2011) found significant correlations between learning gains and GEFT scores in the set of participants with good non-verbal intelligence scores, while correlations were negative for the set of participants with low non-verbal intelligence.…”