Abstract
We have previously used a probe detection task with Multiple Object Tracking and showed that in MOT probes are detected better on targets than on nontargets (VSS 2005) - a result we interpreted as showing that nontargets are inhibited. Here we ask whether the difference between probe detection performance on targets and nontargets is due to the explicit multiple object tracking task that requires observers to keep track of and report targets at the end of a trial, or whether flashed targets are primed and implicitly tracked merely because they are cued by being flashed - in other words, whether a target-nontarget difference in probe detection might be observed when no tracking is explicitly required. We used a modified version of MOT, in which observers were instructed merely to monitor for a probe while some objects moved in their field of view and were occasionally flashed to distract them. In this task no tracking of flashed items was required. We found evidence for better probe detection on flashed than on nonflashed items suggesting that flashed items are implicitly tracked even when there is no explicit requirement for tracking and reporting the cued items.
Supported by NIMH Grant 1R01-MH60924 to ZWP