An object hidden among distractors can be found more efficiently if previously searched locations are not reinspected. The inhibition-of-return (IOR) phenomenon indexes the tendency to avoid reinspections. Two accounts of IOR, that it is due to inhibition and that it is due to expectation, are generally regarded as incompatible. The relevant evidence to date, however, has been indirect: Inhibition or expectation has been inferred from response times or similar indirect measures. This article reports the first direct measure of IOR, obtained by asking observers to predict the location of the next target in a display containing eight possible locations on an imaginary circle. On any given trial, the previously cued location was chosen less frequently (impairment)—and the opposite location was chosen more frequently (facilitation)—than chance (choice of all other locations was at chance). The impairment is consistent with both inhibition and expectation accounts; the facilitation is consistent only with expectation accounts. This work also shows that inhibition and expectation are not necessarily incompatible: Implementing expectations may entail inhibiting previously cued locations.
The role of cue processing in advancing the onset of inhibition of return
