Cerebral lateralization and cognitive functioning in patients with congenital adrenal hyperplasia.

A battery of tests was administered to 17 patients with congenital adrenal hyperplasia (CAH) and 17 normal controls to investigate the effect of prenatal androgen exposure on cerebral lateralization and cognitive performance. Individuals were compared on measures of hand preference, verbal and performance IQ, and temporal processing asymmetry. A higher incidence of left-handedness was found among CAH participants. CAH individuals exhibited higher performance IQs as opposed to verbal IQs. Temporal processing asymmetries were investigated using an auditory gap detection task. Measures of reaction time and response error revealed a right-ear, therefore left-hemisphere, advantage for gap detection. This right-ear advantage did not differ between CAH individuals and controls. Results partially support the hypothesis that prenatal androgen exposure causes a shift in cerebral lateralization toward right-hemisphere dominance.