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Abstract:
Inhibition of Return (IOR), which refers to slower responding
to a stimulus when it appears at a previously stimulated location
relative to when it appears at a new location, has been observed
for a wide variety of experimental tasks and paradigms. The
ubiquitous nature of IOR across many tasks and sensory modalities
indicates that the processes underlying IOR are important and
general mechanisms in the spatial selection of information. There
is growing evidence that IOR may, at least in part, affect
behavioral performance by suppressing perceptual processing at
previously stimulated locations. Because of their high temporal
resolution Event-related Potentials (ERPs) are especially well
suited to study how IOR affects stimulus processing. McDonald and
Ward (P&P, 1999) found that IOR was associated with a reduction
of the occipital P1 component of the visual ERPs to targets in a
visual cue-target experiment. In the present study we examined the
effect of IOR on target elicited ERPs in experiments using the
target-target paradigm. A 64 channel electrode array was used to
record ERPs elicited by visual targets. Participants responded more
slowly to targets appearing successively at the same location than
to targets appearing at different locations. ERPs to target stimuli
exhibited both early and late amplitude modulations due to the
spatial relationship between successive targets. These results
indicate that IOR affects multiple stages of information
processing.
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