PMC

An inflated cortical rendering of the left hemisphere (Van Essen et al., 2001) illustrates significant MPFC activity during direct comparisons between SELF and FRIEND (left), SELF and CASE (middle), and FRIEND and CASE (right).

An a priori region-of-interest (ROI) in MPFC based on Kelley and colleagues () was used to compute mean signal change during SELF-, FRIEND-, and CASE- judgments. Signal intensities for each condition are plotted relative to a baseline control condition (fixating a crosshair). Similar to the previous work, MPFC activity was uniquely sensitive to self judgments. Case-judgments and judgments about an intimate other produced robust decreases in MPFC activity that did not differ from each other.

Examples of the SELF, FRIEND, CASE, and fixation trial types. Trials were randomly intermixed, and one trial was presented every 2.5 s. For each of the three judgment trial types, the ‘cue’ (presented above the central fixation) indicated which type of judgment to make for the trait adjective (presented below the fixation). The paradigm was identical to Kelley and colleagues () with the following exception: the ‘other’ target used by Kelley and colleagues (George W. Bush) was changed to be an intimate other (best friend).