Self, mother and abstract other: an fMRI study of reflective social processing

Using fMRI, we studied the neural correlates of self-referential processing by comparing BOLD signal changes during self and mother conditions of a self-reference effect (SRE) task. Conjunction analysis of these two conditions showed several common areas of significant activation, including the medial aspects of the superior frontal gyri, left inferior frontal gyrus, bilateral temporal poles, left superior temporal sulcus and left precuneus. The locations of the 7 strongest peak activations for the self condition and for the mother condition were compared on a subject-by-subject basis in native space. Of the 119 pairs of peaks explored, 87% were located within 2 voxels of each other, demonstrating the commonality of the brain regions subserving both self- and mother-referential processing within an individual subject. In group analyses of the self-referential vs. mother-referential contrast, small differences in activation strength were observed in the left superior frontal sulcus, right cingulate gyrus and the left fusiform gyrus. Greater activation for mother than for self was observed in bilateral temporal lobes. Subjects also performed a social attribution task (SAT) in which they inferred mental states about interacting geometric shapes. Activations from this visual theory of mind task were compared with the activations demonstrated during self-referential processing. Striking similarities were found, including overlapping activations in bilateral medial prefrontal cortices, left inferior frontal gyrus and precuneus. These data suggest that reflective analysis of self, mother and abstract others relies predominantly on the same neural architecture.