Fig. 1.

Schematic illustration of the experimental design. The paradigm consisted of a modified Go/NoGo-task. Beyond repeated presentation of a target and a highly similar non-target stimulus, the design also included the presentation of novel pictures (each of which occurred only once during the entire experiment). The subjects' task was to make a speeded button-press response upon detection of the target picture, but to withhold their response to the highly similar non-target and novel stimuli.