Systematic variations of the block design task were given to 20 autistic, 33 normal and 12 mildly retarded subjects. Designs were contrasted which were either "whole" or segmented, rotated or unrotated, and which did or did not contain obliques. Only segmentation, but neither of the spatial orientation factors, revealed a significant group difference. Autistic subjects, regardless of age and ability, performed better than controls when presented with unsegmented designs. This result suggests that they need less of the normally required effort to segment a gestalt, and thus supports the hypothesis of weak central coherence as a characteristic of information processing in autism.

An aspect of cognitive functioning in autistic children was investigated by comparing their performance on the Children's Embedded Figures Test with that of MA-matched normal and MA- and CA-matched mentally retarded non-autistic children. The autistic children were significantly more competent at this task than either group of control children, and also showed qualitatively different strategies. Since the performance of the autistic children was better than predicted from MA and commensurate with CA, it can be regarded as an islet of ability. This finding is discussed in terms of orientation and visualization factors involved in visuo-spatial abilities and is also related to cognitive deficit.

Catatonia is a later complication of autistic spectrum disorders, which adds considerably to the burden of caring. More research is needed to identify causes, neuropathology, and early signs of vulnerability.

SynopsisVarious types of reliability measures were conducted on the Disability Assessment Schedule, a structured interview devised to elicit from parents or care staff details of impairments, skills and behaviour problems in mentally retarded children and adults. The results indicated high overall agreement when the schedule was repeated over time, and also when used by several trained interviewers to rate the same interview. Problems arising from the use of such interview schedules are discussed, and suggestions are made for improving the design and method of administration.

The prevalence of AS in Broadmoor Hospital is greater than that reported for the general population.