Abstract
How the two hemispheres of the brain work together in order to create a conscious percept of the world is a fundamental question in neuroscience. It has been shown that the two hemispheres have different response functions to face stimuli (e.g., Rossion et al., 2000; Meng et al., 2012; Rangarajan et al., 2014). However, it is not clear whether lateralization of face-selective representations or different response functions to visual configurations underlie such hemispheric asymmetry. Inversion is known to impair the configural representation of faces (Yin, 1969) and lead to delayed break through times during interocular suppression of visual awareness (Jiang, Costello, & He, 2007). To investigate if the hemispheric asymmetry of face processing relies on conscious experience of configural representations, we designed an experiment using continuous flash suppression to examine breakthrough times of upright and inverted faces and houses at different positions in the visual field. Using a stereoscope, flashing Mondrian patches consisting of circles and squares were presented to the participants’ dominant eye at ~10Hz while the stimuli were presented to the non-dominant eye. Upright faces reliably broke through suppression, replicating previous findings. More interestingly, faces presented to the right hemifield broke through suppression faster than faces in the left hemifield, independently of the inversion effect. For comparisons, no asymmetry was found between the top and bottom visual hemifields and no significant effects of inversion or hemifield were found for houses. These results suggest that the face inversion effect may occur at a preconscious level and independently of the lateralization of face-selectiveness, providing important clues for understanding how the brain is organized to process faces and how the two hemispheres may be specialized for visual representations.
Meeting abstract presented at VSS 2015