[The evaluation of lateralized frontal lobe function in the patients with autistic or attention deficit/hyperactivity...

The prefrontal lobes are involved in two functionally distinct cognitive selection mechanisms: processing based on internal representation, such as planning (context-dependent reasoning) and exploratory processing of novel cognitive situations (context-independent reasoning). On the basis of this working hypothesis, a cognitive bias task (CBT; Goldberg, 1994), designed as an activation procedure representing contextual reasoning, was used to explore developmental disorders of lateralization in the frontal lobes in autistic disorder and attention deficit/hyperactivity disorder (ADHD). The subjects included 3 patients with autistic disorder, 4 with ADHD. Ten normal right-handed males served as controls. In CBT, a high score indicated consistency of choice: a context dependent selection bias, and a low score showed independent selection bias. The autistic group showed a score significant lower than those in controls (p < 0.01). The ADHD group had also a lower score. These findings implicate a deficit in the development of hemispheric specialization in the symptoms of these developmental disorders.