Theory of Mind in patients with ventromedial or dorsolateral prefrontal lesions following traumatic brain injury

Primary objective: Previous studies on patients with traumatic brain injuries (TBI) and diffuse brain damages have reported selective deficits in mental states reasoning or 'Theory of Mind' (ToM). The goal of the current study is to investigate the fundamental role of the prefrontal cortex in two ToM components: inferential reasoning and social perception. Research design: Selective cognitive impairments following a TBI provide crucial evidence for assessing competing models of specific aspects of the cognitive system. Method and procedure: This study compared the performance of patients with predominantly focal lesions in the ventromedial (n = 11) or dorsolateral prefrontal cortex (n = 7) with matched controls (n = 20). All subjects performed two ToM tasks: the Eyes Test and the Faux-pas Test. Results: It was found that both groups of patients performed equally poorly on the Eyes Test, but only patients with predominantly lesions in the ventromedial cortex performed poorly on the Faux-pas test. The group effects on ToM tasks could not be reduced to differences in the global severity of brain injuries. Conclusions: These results provide evidence supporting some current models of the fractionation of the mindreading system and support the claim that the ventromedial cortex plays a fundamental role in inferential reasoning.