A review of: Spek, A.A., Scholte, E.M., Berckelaer-Onnes, I.A. (2008). Brief Report: The Use of WAIS-III in Adults with HFA and Asperger Syndrome. Journal of Autism and Developmental Disorders, 38(4), 782-787. DOI: 10.1007/s10803-007-0446-5

I have documented in previous posts that clinicians and researchers have often proposed that high functioning autism and Asperger’s present a significantly different neurocognitive profile (see here and here). The belief is that children with AS tend to have a significant discrepancy between verbal and non-verbal abilities, with relatively higher verbal functioning as compared to non-verbal skills. On the other hand, children with high functioning autism tend to have relatively equal verbal and non-verbal skills. However, recently I’ve been encountering several studies that suggest that this may not be the case. As reported in this brief yet very elegant study from the Leiden University in the Netherlands, the researchers conducted a cognitive assessment of 16 adults with high functioning autism and 27 adults with Asperger’s syndrome using the WAIS-III (the most common adult IQ assessment instrument). Diagnoses were confirmed via ADI using DSM-IV criteria to differentiate HFA vs. AS. There were no differences between the groups in verbal vs. non-verbal performance (VIQ vs. PIQ). There was no pattern of high-verbal low-non-verbal scores in the Asperger’s group, with both groups scoring in the High Average range for both verbal and non-verbal composite scales. However, one global factor scale difference was observed. Adults with high functioning autism showed a significantly lower Processing Speed as compared to other factor skills such as Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility. This finding was not observed in the Asperger’s group. Despite this difference (and some additional task-specific differences I didn’t mention in this review), the general findings of this study fail to support the idea that people with high functioning autism and Asperger’s can be differentiated on the basis of relative strength and weaknesses in their verbal vs. non-verbal performance as measured by standard intellectual assessment batteries.

A review of: Saalasti, S., Lepistö, T., Toppila, E., Kujala, T., Laakso, M., Nieminen-von Wendt, T., Wendt, L., Jansson-Verkasalo, E. (2008). Language Abilities of Children with Asperger Syndrome. Journal of Autism and Developmental Disorders DOI: 10.1007/s10803-008-0540-3

One of the diagnostic criteria of Asperger’s syndrome (AS) is normative language development, or more specifically: no evidence of language delays. However, the authors of this study argued that there is evidence to suggest that people with AS have impairment in various aspects of language including production and comprehension, making their language fluent but “pragmatically impaired.” Their interpretation of utterances is literal, leading to problems with the understanding of humor, metaphors, idioms, etc. To better understand the nature of these deficits the researchers compared the language skills of 22 children with AS (16 boys) between 7 and 10 years of age (diagnosed via ADOS and ADI) against 22 typically developing children of similar ages and IQ who were recruited from elementary schools. The researchers examined vocabulary, phonological processing, comprehension, repetition (phonological and sentence), fluency, and auditory processing. Children with AS performed significantly worse than typically developing children in the comprehension test (Comprehension of Instructions from the NEPSY) and tended to perform worse in the phonological processing test. No other differences were found. The authors argued that lower scores in the comprehension test are likely due to deficits in self-regulation and executive function, since both skills are necessary for successful performance on the comprehension and phonological processing tests.

A review of:Kuusikko, S., Pollock-Wurman, R., Jussila, K., Carter, A.S., Mattila, M., Ebeling, H., Pauls, D.L., Moilanen, I. (2008). Social Anxiety in High-functioning Children and Adolescents with Autism and Asperger Syndrome. Journal of Autism and Developmental Disorders DOI: 10.1007/s10803-008-0555-9

When I first picked up this article I was excited because it seemed to directly address a clinical feature that some researchers and many clinicians have used to differentiate children with High Functioning Autism vs. Children with Asperger’s. We know that technically, based on DSM-IV diagnosis, the main difference between HFA and AS is the presence or absence of language delays. Kids with HFA, by definition, experience language delays, while kids with Asperger’s have typical language development. But in all clinical settings I have practiced, we have discussed other possible differences between these kids, specifically in regards to their neuropsychological profile and the nature of their limited social interaction with other peers. As for neuropsychological profile, HFA tend to have even verbal vs. non-verbal skills, while children with AS tend to have much higher verbal than non-verbal skills, consistent with the profile of children with “non-verbal learning disabilities”. In regards to their social interactions, in my clinical experience and interaction with colleagues, we see a difference in their ‘relative’ need for social companionship. In general children with HFA seem to just want to be by themselves without an explicit desire to interact with peers. They interact when necessary and when such interaction is functional, but not for the “intrinsic joy” of having social interactions. On the other hand, children with AS tend to desire close relationships with peers and explicitly talk about wanting more friends, but their social uniqueness make the establishing of such relation more difficult. Based on this last apparent clinical difference, you would expect that children with AS would experience more social anxiety due to a relative high need for social acceptance as compared to children with HFA. To test these hypotheses, a group in Finland compared 35 kids with AS, 21 kids with HFA (diagnosed via ADI and ADOS), and a large group of 353 typically developing kids of the same age (8-16 years old). The results were surprising: There was NO difference between the AS and the HFA in anxiety, social anxiety, social phobia, etc. As a group, the children with HFA/AS experienced higher level of anxiety and social phobia than the typically developing children. Furthermore, a developmental trajectory was observed. The anxiety problems tended to decrease with age in typically developing kids, but these problems increased with age in the children with HFA/AS. In summary, the data suggest that children with AS and HFA experience the same levels of social anxiety and phobias, which does not support the clinical view that these children may differ in regards to relative levels of social desirability.

Title: Structural brain abnormalities in adolescents with autism spectrum disorder and patients with attention deficit/hyperactivity disorder.
Author: Brieber, Sarah; Neufang, Susanne; Bruning, Nicole; Kamp-Becker, Inge; Remschmidt, Helmut; Herpertz-Dahlmann, Beate; Fink, Gereon R; Konrad, Kerstin.
Source: Journal of Child Psychology and Psychiatry. Vol 48(12) Dec 2007, 1251-1258.

This is a Magnetic Resonance Imaging (MRI) study of the brains of children with Asperger’s (15), children with ADHD (15), and children with typical development (15). The researchers found that kids with Asperger’s and kids with ADHD did not differ in hyperactivity and inattention symptoms. However, the brains of these two groups differed from those of the typically developing kids in that kids with ADHD and Asperger’s showed less brain mass in a region called the medial temporal lobe and more brain mass in a region called the parietal cortex. However, the most interesting finding is that only the children with Asperger’s showed more brain mass in an area called the right supramarginal gyrus, which is an area of the brain that has been associated with social cognition, including theory of mind. Note: more brain mass does not necessarily mean “better”.

Title: Social maturity and theory of mind in typically developing children and those on the autism spectrum.
Authors: Peterson, Candida C; Slaughter, Virginia P; Paynter, Jessica.
Source: Journal of Child Psychology and Psychiatry. Vol 48(12) Dec 2007, 1243-1250.

The researchers created a new measure of Social Maturity (Sociability, Assertion, peer leadership, social play, coping with peers, and social sensitivity). They examined whether social maturity was related to children’s “theory of mind”, a concept at the center of many Autism theories, and which refers to the child’s ability to recognize other people’s thoughts and intentions from their actions (if you are looking under the table I recognize that you “think” something may be under the table). The researchers found that those children who score high on Theory of Mind tests also scored high on the Social maturity scale. They also found that children with autism scored lower in theory of mind and social maturity than children with typical development. But most interesting, children with Asperger’s did well on theory of mind tests, but not on social maturity tests. This suggests that children with Asperger’s diagnosis may not have impairments in theory of mind but yet they have low levels of social maturity.