The study examined 30 schizophrenic and 30 nonpsychotic but disturbed children (all residents at a psychiatric center and all between 8 and 17 years old) for cognitive deficits in logical thinking, symbolic imagery, and conservation within the Piagetian theory of cognitive development. (Author/SBH)

Sixty-three siblings (and their parents) of individuals with autism or related disorders were interviewed to determine their cognitive sophistication about autism. Although children's reasoning became more mature with age, it tended to develop at a delayed rate compared to norms for illness concepts. Parents tended to overestimate their child's…

This study compared the regulation of cognitive activity in 30 children (ages 15 to 95 months) with autism or mental retardation matched for global, verbal, and nonverbal developmental ages. Testing on tasks of object permanence indicated that the autistic children had a pervasive difficulty in maintenance set, made more perseverative errors, and…

The study of affect comprehension in 15 children with pervasive developmental disorders (ages 7-10) and normal children matched for mental age found that the disabled children were impaired on affect matching compared to the controls and were impaired on face and affect matching relative to their own performance on object matching. (Author/DB)

Findings from relevant research applying Piaget's theory to mental retardation, psychosis, and autism are reviewed. Many autistic individuals show an arrest in operative functions at the sensorimotor functions. The early arrest interferes with subsequent development of higher-level conceptual, symbolic, and social skills. (Author)