Discrepancy between social and nonsocial decision-making under uncertainty following prefrontal lobe damage: the impact of an interactionist approach.

Deficits in decision-making are thought to contribute significantly to socio-behavioral impairments of patients with frontal lobe damage. The purpose of this study was to test the hypothesis of whether the inappropriate social behavior of patients with frontal lesions can be viewed as the product of a general failure of decision-making ability or as the result of socio-cognitive impairment. We studied a group of patients with prefrontal lesions (FL patients, n = 15) and a group of matched healthy controls (n = 30) on the Iowa Gambling task (IGT) of nonsocial decision-making, environmental dependency phenomena (EDP) during social interaction, and the "reading the mind in the eyes" and "character intention task" of theory of mind (TOM) tasks. The FL patients were impaired in both TOM and EDP protocols but, surprisingly, they behaved appropriately in the IGT. In addition, FL patients with EDP did not differ in executive functioning, IGT and TOM measures from those who did not demonstrate these behavioral disorders. The right orbitofrontal cortex was associated with social decision-making deficits. By adopting an interactionist approach, this study raises the possibility of identifying components of social and nonsocial decision-making, which could be helpful in understanding the behavioral disorders of FL patients.