Asymmetric visual interactions across the boundary of awareness

A salient visual object can disappear from conscious perception when surrounded by a moving texture, a phenomenon known as MIB, Motion-Induced Blindness (Bonneh, Cooperman, & Sagi, 2001). Here we tested the information available in the brain from such stimuli that do not access awareness by examining interactions across the boundary of awareness between stimuli that reach awareness and those that do not. Observers performed the MIB task in which a "Cue" was presented next to the "Target" after observers reported the perceptual disappearance of the target (Kawabe, Yamada, & Miura, 2007). Oriented Gabor patches were used as targets and cues; observers reported the target's reappearance. The results indicated an interaction between the target and the cue, depending on the orientation difference (∼30° bandwidth) and distance (∼1° range), indicating preserved properties of features in the absence of awareness. Object-based representation (binding) of unseen stimuli was tested by examining the interaction between a compound stimulus and its composing features. Here we used vertical and horizontal Gabor patches and their combinations (plaids) as targets and cues. Results indicated asymmetric relations between aware and unaware object representations; a plaid cue was not effective with a component target, but a plaid target efficiently reappeared by its component cues. This result suggests that the unseen, but not the seen plaid, is decomposed into its features. Plaid targets also reappeared with plaid cues, supporting binding without awareness. Our findings suggest preconscious representations of objects and their features, with conscious perception confined to object representations.