Dissociation between emotion and personality judgments: convergent evidence from functional neuroimaging

Cognitive neuroscientists widely agree on the importance of providing convergent evidence from neuroimaging and lesion studies to establish structure-function relationships. However, such convergent evidence is, in practice, rarely provided. A previous lesion study found a striking double dissociation between two superficially similar social judgment processes, emotion recognition and personality attribution, based on the same body movement stimuli (point-light walkers). Damage to left frontal opercular (LFO) cortices was associated with impairments in personality trait attribution, whereas damage to right postcentral/supramarginal cortices was associated with impairments in emotional state attribution. Here, we present convergent evidence from fMRI in support of this double dissociation, with regions of interest (ROIs) defined by the regions of maximal lesion overlap from the previous study. Subjects learned four emotion words and four trait words, then watched a series of short point-light walker body movement stimuli. After each stimulus, subjects saw either an emotion word or a trait word and rated how well the word described the stimulus. The LFO ROI exhibited greater activity during personality judgments than during emotion judgments. In contrast, the right postcentral/supramarginal ROI exhibited greater activity during emotion judgments than during personality judgments. Follow-up experiments ruled out the possibility that the LFO activation difference was due to word frequency differences. Additionally, we found greater activity in a region of the medial prefrontal cortex previously associated with "theory of mind" tasks when subjects made personality, as compared to emotion judgments.