Abstract
Previous research has suggested that attention is inhibited from returning to previously attended locations, and that this inhibition of return (IOR) lasts approximately two to three seconds. However, Tipper, Grison, and Kessler (2003) showed that this inhibition can last for much longer durations so long as the cue is encoded in a context-rich event. Using a target-target procedure, Wilson, Castel, and Pratt (2006) extended this work and proposed that IOR, at both standard (i.e. typical time range) and long durations, resulted from a conflict in memory retrieval of the previous response and the current response. However, Wilson et al. only examined situations in which the response change was from withholding a response to production of a response. The question remains, then, whether suppression of a response to the previous target is necessary or whether a change in the type of response (e.g., from a left-hand to a right-hand response) would be sufficient to produce IOR. To examine this possibility, we used standard (1500 ms) and long stimulus onset asynchronies (~10,500 ms SOA) and manipulated the congruency of both the colour of and the response required for the previous and current target. In support of the memory retrieval account, significant IOR was found at the short SOA only when there was a change in motor response, but not a change in the colour feature, suggesting that a change in motor response is sufficient to cause IOR. However, there were two unexpected results: (1) no IOR was found at the long SOA when the response changed, and (2) for both standard and long SOAs, there was significant facilitation when participants were required to make the same response to both the previous and the current target. Overall, these results support that proposal that memory for a conflicting response underlies IOR.
This research was supported by a Natural Sciences and Engineering Research Council of Canada Operating Grant to Daryl Wilson.