Abstract
When people look for things in their environment, they seldom have perfect knowledge regarding the appearance of the to-be-located item. Rather, target "templates" – the mental representations used to guide attention toward targets – vary in their precision, as when looking for your favorite pen, versus any pen at all. We compared visual search performance when target templates were cued by pictures of the items, relative to categorical labels of the targets (i.e., "find a pen"). We examined reaction time, and used a signal detection framework to assess sensitivity (i.e., how well targets were detected) and response bias (how likely people were to respond "present") during search. Participants searched for the same target (or targets) up to four times; target identities were new for each search "block". On each search, participants indicated the presence or absence of the target(s), and then quickly searched again if no targets appeared. Half the participants received reminder cues after each search, to "refresh" their templates. Occasionally, four consecutive target-absent searches were presented. Consistent with prior research, picture cues elicited superior performance: Sensitivity was high, and RTs were fast, relative to search using word cues. However, word cues produced stable performance over time. When people search repeatedly using a picture cue (without reminders after each search), RTs on target-present displays are slowed. Moreover, sensitivity decreases without periodic "refreshing", and this effect is exacerbated when searching for multiple targets. By contrast, although search using word cues is slower overall (and less sensitive), reminders are unnecessary to refresh the target template. A lack of reminders does not hinder performance, nor does it exacerbate the effect of target "load." These results suggest that pictorial templates may guide attention efficiently, but they are prone to decay over time, a caveat that is not shared by categorical templates.
Meeting abstract presented at VSS 2013