Abstract
Forming a durable representation in visual working memory (VWM) requires a relatively time-consuming memory consolidation process, and thus may require involvement of an attentive process. In the present study, we tested whether or not change detection performance can be impaired when a feature-absence target embedded in a sample array is sought after. In Experiment, subjects performed a color change detection task in which sample array was made up of 3 or 6 colored letters (e.g., Q and O). In the simple feature pop-out condition, a target was a letter, ‘Q’ while distracters were all ‘O’s for each trial block of setsize 3 or 6. In the feature-absence search condition, the target designation was reversed. In each trial, subjects were asked to report target presence or absence as quickly as possible upon the sample array, and were asked to report presence or absence of a change when a test probe showed up after a memory delay. In the pop-out search condition, search RTs did not differ across the set size 3 and 6 trials, and change detection accuracy in the setsize 3 trials was higher than setsize 6 trials. In the feature-absence search condition, search RTs were slower in the setsize 6 than setsize 3 trials. Change detection accuracy in the setsize 6 trials was lower than the setsize 3 trials just like as in the pop-out search condition, but the difference of the accuracy was more evident than that in the pop-out search condition. The results indicate that searching for a feature-absence target embedded in the sample array competes for attentional resources during consolidation of the sample items into VWM, whereas searching for a pop-out target does not evoke such competition. This supports for the idea that attention plays an important role when memory items are consolidated into VWM.
This work was supported by the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2010-327-B00832).