Inhibition of Return is a Foraging Facilitator in Visual Search

Abstract

Using overt orienting, participants searched a complex visual scene for a camouflaged target (Waldo from the "Where's Waldo?™" books). After several saccades, we presented an uncamouflaged probe (black disk) while removing or maintaining the scene, and participants were required to locate this probe by foveating it. Inhibition of return was observed as a relative increase in the time required to locate these probes when they were in the general region of a previous fixation, but only when the search array remained present. Perhaps also reflecting inhibition of return, preprobe saccades showed a strong directional bias away from a previously fixated region. Together with recent studies that replicate the finding of inhibition at distractor locations following serial but not parallel visual search-so long as the search array remains visible-these data strongly support the proposal that inhibition of return functions to facilitate visual search by inhibiting orienting to previously examined locations.

Visual search and foraging compared in a large-scale search task

“…Another possibility is that additional cues from kinaesthetic movement through navigational space, such as path integration (Gopal et al 1989), provide a richer and more powerful representation of exploratory behaviour. Lastly, some form of Inhibition of Return (as predicted by Klein and MacInnes 1999) could account for the comparative lack of revisit error in large-scale search, although this approach would not itself account for the differences observed between small-scale and large-scale search. It therefore seems that visual search tasks can partially equate large-scale search when the visual cues to target location are of an equivalent nature.…”

“…The tasks reported here are best conceived as large-scale searches, with either a visually or non-visually guided component. Use of the term foraging has a theoretical precedent (Klein and MacInnes 1999;Wolfe 1994) and has here been used in reference to that discussion, but we suggest that it is discarded in future debate in favour of specification and identification of the precise behaviours being referred to or studied. Spatial behaviour differs greatly across scales and environments, and the coding, representation, utilisation, and retention of spatial information can take a variety of forms depending on the nature of that environment and the task that one is required to perform (see Burgess et al 1999;Humphreys and Riddoch 2005).…”

“…This is closer to the process of foraging as participants were required to move throughout space whilst searching. This paradigm enables a direct comparison of different search behaviours in an identical context, and also allows us to address whether properties of visual search do transpose to large-scale space, as predicted by Wolfe (1994) and Klein and MacInnes (1999). It could also be argued that there is a greater degree of ecological validity in the present paradigm.…”

“…More recently it has been argued that the visual search task represents a well-specified context with which to study more general foraging behaviour (Wolfe 1994), and that some mechanisms identified in visual search tasks are central to foraging. For example, the tendency not to refixate a previously inspected location (Inhibition of Return) has been branded a 'foraging facilitator' (Klein and MacInnes 1999;cf. Hooge et al 2005).…”

“…Serial inspection of potential target locations in large-scale search (Gilchrist et al 2001;Ruddle and Lessels 2006;Smith et al 2005) is more akin to inefficient visual search behaviour, especially in visual search tasks where target complexity necessitates fixation of individual items (e.g. Klein and MacInnes 1999;Gilchrist and Harvey 2000). Yet these tasks also lack a visually guided search component, other than an indication of possible locations.…”