RT Journal Article
SR Electronic
T1 The Pupillary Light Response Reflects Visual Working Memory Content
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 477562
DO 10.1101/477562
A1 Cecília Hustá
A1 Edwin Dalmaijer
A1 Artem Belopolsky
A1 Sebastiaan Mathôt
YR 2018
UL http://biorxiv.org/content/early/2018/11/27/477562.abstract
AB Recent studies have shown that the pupillary light response (PLR) is modulated by higher cognitive functions, presumably through activity in visual sensory brain areas. Here we use the PLR to test the involvement of sensory areas in visual working memory (VWM). In two experiments, participants memorized either bright or dark stimuli. We found that pupils were smaller when a pre-stimulus cue indicated that a bright stimulus should be memorized; this reflects a covert shift of attention during encoding of items into VWM. Crucially, we obtained the same result with a post-stimulus cue, which shows that internal shifts of attention within VWM affect pupil size as well. Strikingly, pupil size reflected VWM content only briefly. This suggests that a shift of attention within VWM momentarily activates an “active” memory representation, but that this representation quickly transforms into a “hidden” state that does not rely on sensory areas.