The fMRI stimuli were comprised of faces obtained from the picture set from the Neuropsychiatry Section of the University of Pennsylvania and consisted of black and white photographs of males and females posing each of three different emotional states (happy, anger, neutral). Emotional and neutral faces were used as the target stimuli and neutral faces from each subject were used as masking stimuli. Scanning epochs consisted of a total of 150 seconds with an additional 6 seconds initially for calibration during which time no data was acquired; thus, the total time required for each condition (masked happy or masked anger) was two minutes, thirty-six seconds. The task was comprised of five alternating blocks which consisted of a total of ten trials. Each individual trial consisted of an emotional or neutral target face presented for 30 milliseconds, followed immediately by a neutral masking face of the same poser for 170 milliseconds. Trials were separated by a 1 second interstimulus interval. Blocks 1, 3 and 5 consisted of neutral targets and neutral masks while blocks 2 and 4 were comprised of emotional
