Decoding Neural Patterns for the Processing of Fearful Faces under Different Visual Awareness Conditions: A Multivariate Pattern Analysis

Abstract

Mixed findings have been reported for the nonconscious processing of fearful faces. Here, we used multivariate pattern analysis on electroencephalography data from three backward masking experiments to decode the conscious and nonconscious processing of fearful faces. Three groups of participants were shown pairs of faces that were presented either subliminally (16 ms) or supraliminally (266 ms) and were required to complete tasks where the face stimuli were either task-relevant (Experiment 1) or task-irrelevant (Experiments 2 and 3). We decoded the neural activity to examine the temporal dynamics of visual awareness, and to investigate whether the presence and location of a fearful face were processed when levels of awareness varied. The results reveal that the spatial location of fearful faces can be decoded from neural patterns only when they are consciously seen and relevant to participants task. Nevertheless, the processing of the mere presence of fearful faces can occur in the absence of visual awareness, and the related neural patterns can be generalised to the conscious, non-spatial processing of fearful faces. Additionally, the flexibility of spatial attention seems to modulate the processing of fearful faces.