The role of social cognition in moral judgment in frontotemporal dementia.

Patients with behavioral variant frontotemporal dementia (bvFTD) exhibit a set of behavioral disturbances that have been strongly associated with involvement of the prefrontal cortex (PFC). Many such disturbances have been linked to impaired moral behavior, especially in regard to "personal" or "emotionally driven" moral dilemmatic judgment, which has been demonstrated to also depend on the integrity of the PFC. In this study, we administered a personal moral dilemma (the footbridge dilemma) and social cognition measures to patients with early bvFTD, who were also assessed with an extensive neuropsychological battery, including moral knowledge, cognitive and emotional empathy, and affective decision-making. BvFTD patients who would push a man off a footbridge (knowing this would kill him) to save the life of five workers who would have been otherwise killed by the train showed significantly lower scores on affective Theory of Mind (ToM) relative to those bvFTD patients who responded negatively. No significant differences were found on other sociodemographic, neuropsychological or social cognition variables. This study reveals that altered dilemmatic judgment may be related to impaired affective ToM, which has important clinical and theoretical implications.