The “rotated heads” task (Begleiter et al., 1984) was used to record the electroencephalogram (EEG) while participants sat in a darkened room in a high-back padded chair. The background of the computer screen remained black for the length of the session. For 80 trials, a white oval with a “nose” and one “ear” was presented. On 40 trials, the “nose” was pointed up and the “ear” was either on the right or the left side of the oval. On the remaining 40 trials, the “nose” was pointed down with the “ear” on either side. Subjects were instructed to identify which side of the “head” the “ear” was on, using an appropriate response button. An additional 160 trials with just the oval required no behavioral response. Stimuli were presented pseudo-randomly for 98 ms with a random inter-trial interval between 1 and 2 seconds. The horizontal radius of the oval was 4.3 cm and the vertical radius was 5.3 cm. Participants sat 65 cm from the screen. Participants were given practice trials prior to beginning the task.
