Dissociating cognitive from affective theory of mind: a TMS study.

INTRODUCTION "Theory of Mind" (ToM), i.e., the ability to infer other persons' mental states, is a key function of social cognition. It is increasingly recognized to form a multidimensional construct. One differentiation that has been proposed is that between cognitive and affective ToM, whose neural correlates remain to be identified. We aimed to ascertain the possible role of the right dorsolateral prefrontal cortex (DLPFC) for cognitive ToM as opposed to affective ToM processes. METHODS 1Hz repetitive transcranial magnetic stimulation (rTMS) was used to interfere offline with cortical function of the right DLPFC in healthy male subjects who subsequently had to perform a computerized task assessing cognitive and affective ToM. RESULTS RTMS over the right DLPFC induced a selective effect on cognitive but not affective ToM. More specifically, a significant acceleration of reaction times in cognitive ToM compared to affective ToM and control items was observed in the experimental (right DLPFC) compared to the control (vertex) rTMS stimulation condition. CONCLUSIONS Our findings provide evidence for the functional independence of cognitive from affective ToM. Furthermore, they point to an important role of the right DLPFC within neural networks mediating cognitive ToM. Possible underlying mechanisms of the acceleration of cognitive ToM processing under rTMS are discussed.