Abstract
The comparison between supra-threshold visual working memory (VWM) representations and sensory inputs was reported to be rapid and automatic (Hyun et al., 2009). In the present study, we examined if engaging attention to a central memory task can impair detection of a peripheral pop-out change during VWM consolidation, maintenance, and recognition. In Experiment 1, the central memory task was a change detection task where subjects remembered colors of four boxes (sample array) and were asked to report presence or absence of a color change when another set of boxes (test array) showed up. They were also asked to detect a pop-out color change among a set of colored boxes displayed at periphery while the central task was being performed. The pop-out change among the peripheral boxes was manipulated to occur immediately after the sample array of the central task disappeared or during the middle of blank duration, or at the same time as when the test array appeared. In Experiment 2, the central memory task was replaced with short-term recognition task of four numbers and subjects were asked to determine whether the test number was in the sample array while the peripheral task was kept the same as Experiment 1. Results of these experiments showed that detection of a peripheral change was impaired both when the change occurred immediately after the sample array offset, and when it occurred during the middle of blank interval. However, this impairment was not observed when the pop-out change occurred simultaneously as the test array appeared. The same pattern of results was observed in Experiment 2. The results indicate that consolidating and maintaining memory items in VWM are resource-demanding process and thus lacking extra capacity for automatic detection of a peripheral pop-out whereas the recognition of memory items is relatively free of capacity-limitation.
This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology (NRF-2010-0010842).