Abstract:

PURPOSE: We perceive a stable visual world despite the retinal image is constantly shifted rapid eye movements (saccades), which normally occur 3-4 times a second. It has been suggested that the brain maintains a stable visual representation by predictively mapping objects to their future retinal loci. Because remapping related neural activation is observed when visual objects are no longer visible before saccades, it is believed that the memory trace of visual objects can also be remapped around saccades. The remapped memory trace has been linked to increased neuronal discharge or enhanced behavioral performance. Here we show that it also generates an inhibitory attentional effect—inhibition of return (IOR)—that is of great importance to e?cient orienting.
METHODS: The participant first fixated a central dot. This dot was then displaced 8 degrees to the left or right, and the participant initiated a saccade to follow it. Around the time of saccade onset, an onset cue was flashed for 30 ms. Eight-hundred milliseconds after the cue onset, a target appeared at either the cued location, the cued retinal locus, or two distance matched control locations, and the participant quickly saccaded to the target. The memory trace of the onset cue was remapped around the first saccade; the behavioral consequence of this memory trace was later revealed by the target. Of great interest to us is whether the memory trace of the cue will also generate an IOR effect, as in tasks in which the cue is presented long before the intervening saccade.
RESULTS: To reveal how IOR evolves as the cue onset time approaches the the ?rst saccade, the time intervals between the cue and the onset of the ?rst saccade were split into four bins. IOR was observed at the cued location in all four bins, including the one in which the cue disappeared only 14 ms before the ?rst saccade.
CONCLUSIONS: The results of the present study show that the remapped memory trace of obejcts can generates not only facilitatory but also inhibitory effects. These effects are both critical to the e?cient sampling of visual information.

Key words: Visual stability, predictive remapping, inhibition of return, saccades