Unconscious face processing shows a different lateralisation pattern

Abstract

Faces contain rich information and play a pivotal role in human daily social interactions. Previous studies have provided evidence for the left-visual-field-advantage in face perception. The current study investigated lateralisation when face stimuli were unconsciously presented using interocular suppression methods. The results showed that when an unconscious face stimulus was presented in one side of the visual field without other face stimuli, the unconscious face in the right visual field could break through interocular suppression faster than that in the left (Experiments 1 and 2). However, this right visual field processing advantage reversed to the left when a face stimulus either with (Experiment 2) or without (Experiment 3) visual awareness was presented concurrently with or prior to (Experiment 4) the unconscious face stimuli. These results showed that the unconscious face might have a different processing pattern compared with the conscious face. The relationship between this novel behavioural observation and known functional lateralisation of the fusiform face areas is discussed, suggesting a dynamic interaction between the two cortical hemispheres may underlie the formation of visual awareness for faces. The current study expands our understanding of face processing lateralisation and provided evidence on the asymmetric inter-hemisphere interaction patterns in forming visual awareness.