Inferior Performance on Embedded Figures Tasks by High Functioning Children and Adults with Autism Consistent with Reduced Local Connectivity & Slower Search Strategy

Background:  Enhanced local processing is considered a characteristic feature of autism and has been associated with superior performance on embedded figures tests. Some recent studies of higher functioning children have not documented this superiority.

Objectives: To assess the impact of age and higher IQ on Embedded Figures performance in autism

Methods: The child groups (ages 8-15 years) consisted of 65 children with HFA (mean age 11.8) and 43 age and IQ-matched typical controls (mean age 11.6). The adult groups included 45 with HFA (16-49 years; mean 23.4) and 53 age and IQ-matched normal controls (16-54 years; mean age 23.8). The child HFA group had a mean Verbal IQ of 102.9 (range 82-129), mean Performance IQ 109.1 (range 87-139); the controls mean VIQ was 106.3 (range 84-125), mean PIQ 107.7 (range 88-129). Mean VIQ of the HFA adults was 104.4 (range 83-133); mean PIQ was 105.5 (range 75-132). Mean VIQ of the adult controls was 107.5 (range 84-126); mean PIQ was 109.0 (range 91-127). The age-appropriate version of the Embedded Figures Test (EFT) was administered using standard procedures.

Results: The mean number correct score for the HFA children (7.1) was marginally lower than that of controls (8.3), p = .06; the difference in mean scores and response times was reliably different when PIQ was covaried with slower responses for the HFA child group. The mean number correct score for the HFA adults (8.4) was reliably lower than that of the controls (10.2), p = .002; response time was also reliably greater for the HFA adults.

Conclusions: HFA children exhibited no superiority on CEFT and a trend toward taking longer to make fewer correct responses.  HFA adults were inferior to peers on the Embedded Figures Test, taking longer and making fewer correct responses.