Experimental Paradigm
The emotional conflict task was performed as previously described (15, 16). Stimuli were presented with the Presenta¬tion software package (Neurobehavioral Systems, http://nbs.neuro-bs.com) during fMRI scanning and displayed through a custom-built MRI-compatible projection system. The task con¬sisted of 148 presentations of happy or fearful facial expression photographs drawn from the set of Ekman and Friesen (38), over¬laid with the words “FEAR” or “HAPPY.” Stimuli were presented for 1,000 msec, with a varying inter stimulus interval of 3000–5000 msec (mean=4,000 msec), in a pseudorandom order, counterbal¬anced across trial types for expression, word, response button, and gender. Participants indicated facial affect with a button press response. Behavioral data were analyzed in SPSS (SPSS, Inc., Chicago). For the behavior-only task, a questionnaire was administered after the task to assess participants’ awareness of the conflict adaptation effect.