What Type of Awareness Does Binocular Rivalry Assess?

Abstract

Recent experiments demonstrate that invisible stimulus features can induce binocular rivalry, indicating the phenomenon may be caused by differences in perceptual signal strength rather than conscious selection processes. Here, we clarify binocular rivalry's role in consciousness research by highlighting a critical difference between two distinct types of visual awareness.

Keywords: Awareness; Binocular rivalry; Blindsight; Consciousness.

Figure 1. Perceptual awareness vs. subjective awareness

The two notions of consciousness can be assessed by comparing the following conditions: a) Normal conscious perception - a participant receives visual input, experiences a conscious representation of the stimulus, and reports their experience via a motor response. b) Subliminal/No perception - visual input is identical to a) but the information fails to get through perceptual processing, such that neither a conscious percept nor an explicit response is generated. c) Blindsight - the same visual input gets through perceptual processing roughly as effectively as in a) and a similar motor response is produced, yet the participant does not subjectively experience seeing the stimulus. Whereas comparison between a) and b) reveals mechanisms for perceptual awareness, to isolate and assess subjective awareness, one needs to make sure that task performance capacity is matched, as in the comparison between a) and c).