Abstract
The question of whether facial identity could be processed and represented in the brain in the absence of awareness remains unresolved and controversial. We took the view that visual information suppressed from awareness could be processed to different degrees dependent on the level of suppression. In this study, we investigated whether identity processing of invisible faces depends on how deep it was suppressed from awareness. In different experiments, gratings and faces, rendered invisible with interocular Continuous Flash Suppression (CFS), were used as adaptors to induce orientation and face-identity aftereffect. The strength of interocular suppression was manipulated by adjusting the contrast of the CFS noise. Results from the grating experiment showed that the orientation-specific adaptation effect from invisible gratings was stronger at lower CFS contrast. In the face adaptation experiment, we found no identity-specific aftereffect under high CFS contrasts, consistent with reports from previous studies using the interocular suppression paradigm. However, at lower CFS contrast, while the faces remained invisible (supported with both subjective and objective measures of visibility), significant identity-specific face aftereffect was observed. These findings suggest that although awareness state can be described in binary terms (i.e., with or without awareness), different degrees of information processing could occur in the absence of awareness; that the human visual brain can process face identity information in the absence of awareness.
Meeting abstract presented at VSS 2015