Purchase this article with an account.
Christof Körner, Iain D Gilchrist; Target tagging in visual search. Journal of Vision 2003;3(9):70. doi: 10.1167/3.9.70.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Gibson et al. (2000) reported reaction time results from a visual search task in which participants searched for one versus two targets. These results suggested that targets were tagged, i.e., that there is memory in visual search.
We report two experiments in which we replicate the Gibson et al. (2000) task and employ a traditional target present-absent search task. We also recorded participants' eye movements. There were four key conditions in two blocks: one-target vs. two-target and target-present vs. target-absent.
In Experiment 1 we replicated the manual response times for the multiple target search. If search proceeded in a serial exhaustive manner we would expect identical performance in the one-target and the target-absent conditions. However, response times were longer and the number of fixations was greater in the one-target condition. This suggests that there was a cost associated with tagging the target.
The eye movement data from Experiment 2 showed that this difference was due to an increase in the number of distractor refixations in the one-target condition. Specifically, in the one-target condition the proportion of fixations made after the first target fixation was substantially greater than would be expected from analysis of any of the other conditions.
These results suggest that searching for multiple targets and tagging targets carried a cost as measured by search performance. In turn, these differences suggest that this target-tagging process is not the same one that is deployed to tag distractors in traditional target present-absent search.
This PDF is available to Subscribers Only