Event-related potentials (ERPs) were measured in response to the objective offset of a visual disk under two physically similar
conditions: (1) visible conditions in which the target disk was well perceived and (2) invisible conditions in which participants
reported to have not seen the target because of motion-induced blindness (Bonneh, Cooperman, & Sagi in Nature 411:798–801,
2001). Electrophysiological responses to the physical offset of the target disk were almost completely absent in the invisible
conditions (Experiment 2). In the same conditions, the physical offset was almost completely invisible (Experiment 1). Results suggest an augmenting function of prior awareness of a stimulus for the offset-triggered ERP of that stimulus.