Fronto-limbic functioning in children and adolescents with and without autism

We used neuropsychological tasks to investigate integrity of brain circuits linking orbitofrontal cortex and amygdala (orbitofrontal–amygdala), and dorsolateral prefrontal cortex and hippocampus (dorsolateral prefrontal–hippocampus), in 138 individuals aged 7–18 years, with and without autism. We predicted that performance on orbitofrontal–amygdala tasks would be poorer in the Autism group compared to the Non-Autism group regardless of intellectual level (verbal mental age, VMA) and that performance on dorsolateral prefrontal–hippocampus tasks would be associated primarily with intellectual level. Predicted differences between Autism and Non-Autism groups on orbitofrontal–amygdala tasks were present but greater in individuals with higher VMA. On dorsolateral prefrontal–hippocampus tasks, poorer performance by the Autism compared to the Non-Autism group was found at all VMA levels. Group differences suggest both brain circuits are impaired in autism, but performance on all tasks is also associated with intellectual level.