Abstract
Working memory is susceptible to disruption from an intervening task, yet it is unclear how this disruption is influenced by the representational state of the memories. Recent behavioral evidence suggests that distraction might differentially impact information stored in high- vs. low-priority states in working memory. For example, Makovski & Pertzov (2015) showed that high-prioritized representations receive a protective benefit, while more recently others have suggested that such representations are preferentially susceptible to distraction (e.g., Allen & Ueno, 2018). Here, we sought to leverage neuroimaging to bring new insight into this debate. We trained category-level pattern classifiers with fMRI data and decoded visual working memory representations during a memory delay both before and after a 5-sec distractor task. After encoding two visual stimuli, a retro-cue selected one of the items to be tested by a recognition probe at the end of the trial. Participants knew that this cue could later get reversed, thus they couldn’t completely forget the uncued item, but rather should de-prioritize that item (e.g., Lewis-Peacock et al., 2012). Before distraction, classifier evidence was higher for the cued item. After the 5-sec distraction, a second retro-cue indicated whether the participant should “stay” with the cued item, or “switch” to the previously uncued item for the upcoming memory test. Classifier evidence for both memories dropped during distraction, but recovered afterwards. On switch trials, participants cleanly recovered the previously unprioritized memory, with classifier evidence for the now-relevant category showing separation from the irrelevant category. However, when participants attempted to recover a prioritized memory on stay trials, both the prioritized item and the unprioritized item reemerged, with no separation between classifier evidence for the relevant and irrelevant categories. These preliminary (N=9) results suggest that the neural representation of a high-priority visual working memory is preferentially susceptible to interference from a secondary task.
Acknowledgement: R01 EY028746 (JLP)