Motion-induced blindness continues outside visual awareness and without attention

Abstract

Visual phenomena demonstrating striking perceptual disappearances of salient stimuli have fascinated researchers because of their utility in identifying neural processes that underlie subjective visibility and invisibility. Motion-induced blindness (MIB) is appealing for such purposes because it, like a class of ostensibly related paradigms such as binocular rivalry, features periods of unequivocal subjective disappearances despite constant physical stimulation. It remains unclear, however, exactly how the mechanisms that cause MIB are related to subjectively observed fluctuations in visual awareness. To address this question, we used continuous flash suppression (CFS) to present the MIB stimulus outside visual awareness. Results indicated that MIB occasionally reappeared from suppression with its salient yellow target absent. To quantify this observation, we measured reaction times (RTs) to detect the yellow dot target following visible or perceptually suppressed MIB and indeed found no difference in RTs between these conditions. We also provide evidence that MIB fluctuations can occur without attention. In sum, these experiments indicate that MIB fluctuations are effectively changes in stimulus strength, which under typical conditions result in unmistakable subjective disappearances, but are not inherently fluctuations in stimulus visibility. More broadly, these results challenge the assumed privileged link between bistable stimuli and visual awareness.

Asymmetric visual interactions across the boundary of awareness

“…A visible stimulus selectively facilitates the reappearance of the suppressed object as a function of features similarity. As with any other study involving visual awareness, our conclusions depend on the authenticity of subjective report of disappearance (see below) but do not require the transitions between awareness states to be awareness dependent (Dieter, Tadin, & Pearson, 2015).…”

Does visual attention drive the dynamics of bistable perception?

“…4a ). This finding is consistent with occasional perceptual disappearance of the target dot immediately following the attention shift (Dieter, Tadin, et al, 2015), suggesting that target dot suppression had occurred while attention was still directed to the RSVP task. The authors further found no evidence that the frequency of target disappearances differed between this inattention condition and one in which the RSVP stimulus, while present, was ignored ( Fig.…”

“…As outlined above, the convergence of evidence suggests that BR alternations, and perhaps suppression itself, cease in the absence of attention. Adapting the approach used by Brascamp and Blake (2012) to study BR during periods of inattention, Dieter, Tadin, and Pearson (2015) found that MIB continued to induce target disappearances even during periods of complete inattention. This study utilized a display in which both a MIB stimulus and a rapid serial visual presentation (RSVP) task were displayed, with observers instructed to switch attention between them.…”

Relearning to See in Cortical Blindness

“…While there are many instances of unconscious perception affecting conscious perception (e.g. Dieter and others 2015; Lin and He 2009), typical perceptual experience is marked by conscious discriminations, while blindsight is marked by unconscious discriminations. Furthermore, there appear to be differences in the efficacy of training in different subjects in terms of restoring awareness.…”