Social Cognition In Patients With Lesions In Prefrontal Cortex

Objective Social cognition refers to the processes that subserve behavior in response to conspecifics (other individuals of the same species), and, in particular, to those higher cognitive processes subserving the extremely diverse and flexible social behaviors that are seen in primates. We found that social cognition and social functioning impairments following damage to the prefrontal cortex, but the role of different subregions of the prefrontal cortex in social cognition was not clear. The present study aimed to test the hypothesis that prefrontal cortex was involved in the special network of social cognition.Methods 22 patients with lesions in orbitofrontal areas, 19 patients with lesions in dorsolateral prefrontal cortex and 40 healthy controls were administered with a neuropsychological battery for social cognition, including social cues recognition and social problem solving abilities. Social cues recognition abilities were measured by two tasks: eye basic emotion discrimination task and Faux pas recognition task, and social problem solving abilities were also measured with two tasks: Iowa gambling task and risk-taking task.Results Compared with heath controls, both patients with lesions in orbitofrontal and dorsolateral prefrontal cortex demonstrated an impairment of eye basic emotion discrimination(P <0.01); Patients with lesions in dorsolateral prefrontal cortex showed significant diffence in sad and digust emotion recognition(P<0.01), but patients with lesions in orbitofrontal cortex showed significant diffence in surprise,fear,sad,disgust,anger emotion recognition(P<0.05). For Faux pas recognition task, heath controls and patients with lesions in dorsolateral prefrontal cortex correctly detected the Faux pas and answered control questions. In contrast, almost all of the patients with lesions in orbitofrontal areas made errors detecting faux pas(P<0.001), answering that nothing awkward had been said in the story, but they could correctly answer control questions(P>0.05). The result also showed patients with lesions in dorsolateral prefrontal cortex didn't correctly answer the Faux pas related questions(P<0.01). In Iowa gambling task, heath controls and patients with lesions in dorsolateral prefrontal cortex began by selecting more from the bad decks (1 and 2), but as the game progresses, they gradually shifted their selections toward the good decks (3 and 4), but patients with lesions in orbitofrontal areas did not exhibit this advantageous shift in decision-making, and continued selecting more bad decks. In risk-taking task, heath controls made fewer risky responses after punishment than after reward (P <0.01, i.e. inhibition effect of punishment), and patients with lesions in dorsolateral prefrontal cortex had the similar inhibition effect of punishment (P<0.05), but patients with lesions in orbitofrontal areas showed no inhibition effect of punishment (P>0.05). Compared with performance of the controls, patients with lesions in orbitofrontal areas made more risky responses after both reward and punishment (P<0.05), but patients with lesions in dorsolateral prefrontal cortex showed no significant difference with that of controls (P>0.05).Conclusions The results confirmed that patients with lesions in prefrontal cortex had deficits of social cognition, including social cues recognition and social problem solving abilities. The study also supported that patients with lesions in orbitofrontal areas impaired extensive social cognition, and patients with lesions in dorsolateral prefrontal cortex impaired social perception, but had no impaired in social problem solving abilities(including risk-taking and gambling tasks).