Abstract
We are often faced with the task of searching our visual environment for multiple objects, such as when searching for any one of our friends at Club Vision. To accomplish this search we must retrieve information stored in long term memory (LTM). Surprisingly, searching through memory adds little cost to the efficiency of visual search. That is, visual search response times increase logarithmically with the number of targets stored in LTM (Wolfe, 2012, Psychol Sci): It doesn’t take much longer to search for sixteen friends than it does to search for eight. In this previous investigation, memorized targets were both perceptually identical to the visual search targets, and repeated frequently throughout the search task on target present trials. These conditions are conducive to a familiarity-based LTM process, which may have driven the efficiency of search. In the present study, we evaluated whether LTM-supported search remains efficient when based on flexible, abstract memory representations (i.e., recollection, rather than simple judgements of familiarity). Participants memorized 1, 2, 4, 8 or 16 targets, counterbalanced across blocks, and searched for these targets amidst twelve on-screen distractors. Experiment 1 used predominately target-absent trials and blocks terminated after the first successful target-present trial, ensuring that familiarity did not accrue over repeated presentations of the target. In Experiment 2, this task was extended by having participants memorize written object names and visually search for pictures of those objects, thereby eliminating perceptual familiarity. Despite these restrictions on the contribution of familiarity, we continued to see the efficient logarithmic relationship between visual search time and memory set size. These data suggest that interactions between visual search and LTM search are not completed solely based on familiarity; rather, participants can engage a recollection-based LTM process, calling upon flexible memory representations to support efficient visual search, even for previously unobserved information.
Meeting abstract presented at VSS 2013