Multisensory Processing of Facial Expressions in Binocular Rivalry

Binocular rivalry occurs when two percepts, each presented to a single eye, compete for perceptual dominance. Across two experiments, we investigated whether emotional music influenced perceptual dominance of an emotionally congruent face. In the first experiment, participants heard music (happy, threatening, none) while viewing a positive or negative emotional face pitted against a neutral face or emotional faces pitted against each other. Several key findings emerged. As expected, emotional faces significantly dominated over neutral faces, irrespective of music. For emotional face pairings, negative faces were predominantly reported as initial percepts. Interestingly, this negativity bias was transient and did not persist for the duration of the trial. Rather, positive faces dominated perception throughout trials. Moreover, emotional music affected rivalry dynamics such that congruent music drove attention toward congruent emotional percepts and incongruent music suppressed incongruent percepts. In a second experiment with the same group of participants, we investigated whether explicit attention modulated binocular rivalry of emotional faces. We demonstrated that attention affected both initial and sustained percepts by suppressing automatic emotional biases and stabilizing attention-congruent expressions. Together, our results demonstrate the importance of investigating multisensory expression perception in transient and sustained contexts, the role of emotion as a mediator of sensory integration across perceptual modalities, and the influence of attention on emotional competition in binocular rivalry.