Neural dynamics of induced throat vibrations during vocal emotion recognition

Despite a large literature on the psychological and brain mechanisms of emotional prosody perception, the perspective of embodied cognition on these mechanisms has been largely neglected. Here we investigated the influence of induced bodily vibrations near the vocal tract on the categorization of emotionally ambiguous vocalizations while acquiring event-related potentials (ERPs) through electroencephalography. Emotional voices were morphed between a fearful expression and the speakers identity-matching angry expression, creating blends of emotions in each voice. In line with our hypotheses, behavioral results revealed that induced vibrations biased the participants emotion categorizations. Namely, induced throat vibrations of anger shifted responses toward anger for the most ambiguous voices, while fear vibrations shifted responses toward fear for anger-leaning voices. ERPs indicated that both anger and fear vibrations modulated frontocentral amplitude from about 75 ms, with the sign of the effect depending on time bins and morphing levels. These modulations show that vibrations are registered from early stages of processing. Source reconstruction highlighted effects of vibration types in prefrontal, cingulate, parietal, and medial and lateral temporal cortices, and to a lesser extent in somatosensory and insular cortices. Our results suggest that voice-associated vibrations may contribute to vocal emotion processing through an embodied feedback mechanism.