'Do I like this person?' A network analysis of midline cortex during a social preference task.

Human communication and survival depend on effective social information processing. Abundant behavioral evidence has shown that humans efficiently judge preferences for other individuals, a critical task in social interaction, yet the neural mechanism of this basic social evaluation, remains less than clear. Using a socio-emotional preference task and connectivity analyses (psycho-physiological interaction) of fMRI data, we first demonstrated that cortical midline structures (medial prefrontal and posterior cingulate cortices) and the task-positive network typically implicated in carrying out goal-directed tasks (pre-supplementary motor area, dorsal anterior cingulate and bilateral frontoparietal cortices) were both recruited when subjects made a preference judgment, relative to gender identification, to human faces. Connectivity analyses further showed network interactions among these cortical midline structures, and with the task-positive network, both of which vary as a function of social preference. Overall, the data demonstrate the involvement of cortical midline structures in forming social preference, and provide evidence of network interactions which might reflect a mechanism by which an individual regularly forms and expresses this fundamental decision.