Shape specific inhibition of return

Abstract

Inhibition of the return (IOR) of attention is thought to facilitate visual search by encouraging the movement of attention to new locations or objects. Previous work has shown that IOR associated with realistic objects can be retrieved from memory after long intervals and intervening events. Furthermore, object-based IOR was shown to be mediated by object identity, as IOR does not spread to semantically related items (Morgan, Paul, & Tipper, 2005). The current experiments examined whether IOR can operate on the identity of briefly presented meaningless shapes. Attention was twice oriented to the left or right by the presentation of a red cue shape, then a green target shape requiring a rapid localisation response appeared on the left or right. The results revealed that IOR over short intervals was greater when the cue and target shapes were identical than when they were different, showing that IOR can be associated with the identity of meaningless shapes. However, no long-term IOR was observed for identical shapes, which suggests that long-term memory encoding and retrieval of IOR can only occur if the inhibition is associated with the identity of meaningful objects.

Notes

¹Importantly, an independent-samples t-test using just the uncued data found no significant RT difference between the identical shapes and different shapes conditions, t(34) = 0.8, p=.4, which shows that the Cueing×Shape interaction is not due to differences in the participant sample.

²While the current study deals with one potential locus of the IOR effect, namely the type of object representations underlying IOR, it does not intend to differentiate between alternative IOR explanations. Therefore, is not clear whether these shape specific IOR effects reflect inhibition of attentional orienting (e.g., Reuter-Lorenz, Jha, & Rosenquist, 1996), motor responses (e.g., Klein & Taylor, 1994), or a combination of both (e.g., Abrams & Dobkin, 1994; Taylor & Klein, 2000).