Detailed Information Perception in Adults with HFA or Asperger Syndrome; Assessment and Interpretation

Background:

The weak central coherence account has been modified. A local or detail-focused information processing style seems crucial in autism. Research in detailed information processing in adults with ASD is limited; it remains undetermined if, and to what extent adults with HFA or Asperger syndrome have an enhanced local perception. Most studies used neuropsychological tests to assess detailed information processing, although no test have been developed specifically with this aim. Self-reports have not been used to measure detailed information perception in individuals with ASD. However, the ‘explicit’ theory of mind of adults with ASD may enable them to recognize and describe their strengths and weaknesses adequately.

Objectives:

To examine whether adults with HFA or Asperger syndrome have a detailed information processing style, results of two neuropsychological tests and two self-report questionnaires have been compared to a matched group of neurotypical individuals. Correlations between the tests and the questionnaires have been used to assess validity of the instruments. Further, the influence of processing speed on detailed information perception has been investigated.

Methods:

Forty-two (42) adults with high functioning autism, forty-one (41) adults with Asperger syndrome and forty-one (41) matched neurotypicals participated in the study. The groups were matched in age, gender, handedness, full scale IQ and verbal abilities. The ADI-R was used in the diagnostic process, differentiation between HFA and Asperger was based on criteria of ICD-10 and Gillberg & Gillberg. In the assessment of detailed information perception, the Embedded Figures Test and the Block Design subtest of WAIS III were used as neuropsychological tests and the Systemizing Quotient and the subscale ‘attention to detail’ of the Autism Spectrum Quotient were used as self-reports.

Results:

The three groups did not differ in performance on the Block Design task. In the Embedded Figures Task, the neurotypical group showed significantly better performance compared to the HFA group, which can be attributed to the relatively low processing speed in the HFA group. Absent, or only weak correlations were found between self-reported detailed information processing and the two neuropsychological tasks in the three groups. The HFA and Asperger syndrome groups reported higher levels of self-perceived detailed information processing and a stronger tendency to use systemizing strategies compared to the control group.

Conclusions:

The present study indicates that adults with HFA or Asperger syndrome are, at least partly, capable of recognizing their tendency to detailed information processing. In this area, they have more self-knowledge and introspective abilities than previously thought. The results further suggest that the EFT and the Block Design task may not be valid indicators of detailed information processing in adults in general. In assessing detailed information perception in adults with HFA or Asperger, the use of self-reports might be preferred over the use of neuropsychological tasks. The present study further indicates that systemizing may be a way of coping with a detailed information perception for the two disorder groups, but also for the neurotypical group. This confirms recent theories describing detailed information processing as a cognitive style, rather than a deficit in central coherence.