Abstract
Our previous study found that limiting the duration of exposure to target features ahead of a search could add a constant search delay, suggesting that search execution is held for a coherent target template (Chang & Hyun, VSS 2013). What was unclear was the purpose of waiting for the coherent template. To clarify this issue, we manipulated the exactness of target designation ahead of conjunction search while limiting the time for the template formation. These manipulations tested whether the search is executed impetuously by accommodating an inefficient search with an imperfect target template, or postponed until a coherent target template is ready for an efficient search. Experiment 1 used a conjunction search array of 4, 8, and 12 items consisting of colors and orientations, and Experiment 2 added shapes for triple-conjunction. In each trials, the pre-cue display, which was presented for 100ms in Experiment 1 and for 200ms in Experiment 2, had either an item looking 'exactly' like the target or a set of 'informative' items each sufficiently designating the target features, followed by a 50 or 700ms blank interval until the search array. The results showed that the RTs of the informative condition were relatively slower than the exact condition, and this delay was more evident in the 50ms condition, indicating that extra time was spent for the formation of a coherent target template in the informative condition. Nevertheless, the RTs for both pre-cue conditions were constantly delayed across the set sizes, regardless of the intervals, leaving no drops in search efficiency. The results suggest that, if the time for a coherent target template lacks, search execution is temporarily held for a set amount of time to prevent an impetuous execution of an inefficient search under an imperfect target template.
Meeting abstract presented at VSS 2014