Probing distracter inhibition in visual search: Inhibition of return

The role of inhibition of return (IOR) in serial visual search was reinvest igated using R. Klein's (1988) paradigm of a search task followed by a prob e-detection task. Probes were presented at either the location of a potenti ally inhibited search distracter or an empty location. No evidence of IOR w as obtained when the search objects were removed after the search-task resp onse. But when the search objects remained on, a pattern of effects similar to Klein's results emerged. However, when just the search-critical object parts were removed or when participants received immediate error feedback t o prevent rechecking of the search objects, IOR effects were observed only when probes appeared equally likely at search array and empty locations. Th ese results support the operation of object-based IOR in serial visual sear ch, with IOR demonstrable only when rechecking is prevented (facilitating t ask switching) and monitoring for probes is not biased toward search object s.