Spatial working memory in Asperger's syndrome and in patients with focal frontal and temporal lobe lesions.

Spatial working memory (SWM) was investigated in 15 patients with Asperger's syndrome (AS) comparing their performance to 18 age- and IQ-matched control subjects. An additional comparison was made with 20 unilateral frontal excision patients [9 right (RFL); 11 left (LFL)] and with 38 unilateral temporal lobectomy patients [18 right (RTL); 18 left (LTL)], the frontal and temporal lobe patients having separate matched control groups. SWM was tested using the Executive Golf Task, a test that also measures spatial strategy formation. The AS group showed a substantial deficit on SWM, but no impairment in strategy formation. The LFL showed the same pattern of impairment, but with a less substantial deficit. The RFL group showed a large deficit, but some of this was accounted for by a strategy formation impairment. Of the temporal lobe lesions groups, only the RTL group was impaired on SWM, but this group showed normal strategy formation. It was concluded that the SWM deficit in AS may reflect a more general difficulty in accessing different types of representations in order to guide voluntary behavior, providing at least a partial explanation for the executive deficits found in AS. Copyright 1999 Academic Press.