Frontal lobe contributions to theory of mind

"Theory of mind," the ability to make inferences about others' mental state s, seems to be a modular cognitive capacity that underlies humans' ability to engage in complex social interaction. It develops in several distinct st ages, which can be measured with social reasoning tests of increasing diffi culty. Individuals with Asperger's syndrome, a mild form of autism, perform well on simpler theory of mind tests but show deficits on more development ally advanced theory of mind tests. We tested patients with bilateral damag e to orbito-frontal cortex (n = 5) and unilateral damage in left dorsolater al prefrontal cortex (n = 5) on a series of theory of mind tasks varying in difficulty. Bilateral orbito-frontal lesion patients performed similarly t o individuals with Asperger's syndrome, performing well on simpler tests an d showing deficits on tasks requiring more subtle social reasoning, such as the ability to recognize a faux pas. In contrast, no specific theory of mi nd deficits were evident in the unilateral dorsolateral frontal lesion pati ents. The dorsolateral lesion patients had difficulty only on versions of t he tasks that placed demands on working memory.