Figure 1.

Tasks and experimental design. The visual display consisted of four rapid serial visual presentation (RSVP) streams presented simultaneously in each visual field quadrant and a pair of faces presented horizontally. Task relevance is indicated in red. (A) Match digits low task. Subjects had to monitor the lower left stream for the appearance of digits and indicate via button press if the digits matched or mismatched the target. Distractor streams had to be ignored. (B) Match digits high task. The upper left and lower right RSVP streams were defined as target locations. Simultaneously appearing digits were considered as targets. Participants had to indicate via button press whether the digits were the same (match) or different (mismatch). (C) Match gender task. Subjects had to attend the faces and determine whether they match in gender (match) or not (mismatch). (D) Match emotion task. Subjects had to decide whether the facial expressions match (match) or not (mismatch). (E) Spatial location of the face stimuli. Pairs of faces were presented either in the central-, mid-, or peripheral-position. (F) The stimulation paradigm employed for functional imaging. One block consisted of four different tasks, each lasting 20 s, separated by a Fixation condition and repeated three times.