Working memory can enhance unconscious visual perception

Abstract

We demonstrate that unconscious processing of a stimulus property can be enhanced when there is a match between the contents of working memory and the stimulus presented in the visual field. Participants first held a cue (a colored circle) in working memory and then searched for a brief masked target shape presented simultaneously with a distractor shape. When participants reported having no awareness of the target shape at all, search performance was more accurate in the valid condition, where the target matched the cue in color, than in the neutral condition, where the target mismatched the cue. This effect cannot be attributed to bottomup perceptual priming from the presentation of a memory cue, because unconscious perception was not enhanced when the cue was merely perceptually identified but not actively held in working memory. These findings suggest that reentrant feedback from the contents of working memory modulates unconscious visual perception.

Working memory-driven attention improves spatial resolution: Support for perceptual enhancement

“…This pattern of results suggests that merely priming an object's representation did not influence spatial resolution, although the object was perceptually identified. This is in line with the findings of previous studies that showed null effects of perceptual priming from a visual cue on visual search when the cue is irrelevant to the search task (e.g., Pan, Cheng, & Luo, 2012;Soto, et al, 2005;2010). We also compared accuracy on the spatial resolution task between Experiments 2 and 3, which yielded a significant interaction effect, F(1, 38) = 6.112, p = .018, partial η 2 = .139.…”

“…Previous research has shown that working memory-driven attention can improve identification accuracy or sensitivity to a target when it appears at the location of the memorymatching item in the visual field (Han, 2015b;Pan, Cheng, & Luo, 2012;Soto, et al, 2010). However, because the reported attentional effect occurred only under the condition where the target was always presented with distractors and followed by masks, it might be due to the mechanisms of spatial uncertainty reduction and/or external noise exclusion (Cosman & Vecera, 2011;Dosher & Lu, 2000a, 2000bShiu & Pashler, 1994).…”

“…The present work goes beyond previous studies, which established the effects of working memory-driven attention on perceptual identification of a target in the presence of external noise (Han, 2015b;Pan, Cheng, & Luo, 2012;Soto & Humphreys, 2006;Soto, et al, 2010). Here, we show that working memory-driven attention improves identification of a Landolt target with no external noise added, hence providing direct evidence suggesting that memory-based attention can enhance early perceptual processing through fine-grained spatial analysis at the attended location.…”

“…By presenting the target alone without any external noise added (i.e., no distractors or postmasks), here we show that identification accuracy of a single target was improved when it appeared at the location previously occupied by the stimulus that matched the object cue held in working memory. This result is unlikely be attributable to the mechanism of repetition priming, because we failed to observe priming effects under the condition of mere exposure to the cue (see also Pan et al, 2012;Soto & Humphreys, 2006;Soto et al, 2010). This suggests that the attentional facilitation is due specifically to working memory maintenance; attention is biased by working memory contents to the location of the memory-matching item and enhances the quality of the target representation at the attended location.…”

Tuning perception: Visual working memory biases the quality of visual awareness

“…Previous studies of visual awareness have tended to use coarse measures of awareness, such as forced-choice judgments of shape or pattern (e.g., Olivers, Meijer, & Theeuwes, 2006;Pan, Cheng, & Luo, 2012). That is, most studies of visual perception have tended to focus on the question of sensitivity.…”