Congruence with items held in visual working memory boosts invisible stimuli into awareness: Evidence from motion-induced blindness

摘要

Attention and awareness are intimately related a?? with the former sometimes serving as a gateway to the latter, as in phenomena such as inattentional blindness. Other recent work suggests that attention and visual working memory (VWM) are also intimately related. For example, objects that are congruent with items held in VWM tend to attract attention. Combining these insights leads to the intriguing possibility that VWM congruence could make otherwise-invisible stimuli visible. We tested this by exploiting Motion-Induced Blindness (MIB), wherein salient targets fluctuate into and out of conscious awareness in the presence of a superimposed global motion pattern. A single number was presented at the beginning and end of each trial, and observers had a simple VWM task: Was the final number the same as the initial one? During retention, observers viewed an MIB display with two targets (in the two upper display quadrants), each the number '8' drawn as a rectangle with a single bisecting line. Observers held down independent keys to indicate when the two targets disappeared. While both were invisible, line segments on each target gradually faded out to yield two other numbers (e.g. "5" and "2"), one of them congruent with the VWM number. After the two targets reappeared, observers indicated which of them (left, right, or both) had become visible first. Whether the VWM number was a numerical digit or a written word, the VWM-congruent target was more likely to reappear first a?? an effect not due to endogenous attention (since observers didn't know which invisible target would be congruent until it reappeared) or to a response bias (since it did not occur in catch trials that forced simultaneous reappearance). This discovery shows how VWM congruence can boost invisible stimuli into awareness, and suggests new types of interactions between VWM, attention, and awareness.