Similarities and differences in neural processing of emotional prosody in speech and nonspeech contexts

This study investigated the neural mechanisms underlying the pre-attentive processing of emotional prosody in speech and nonspeech contexts. Participants completed a double-oddball electroencephalography experiment by passively listening to speech sounds spoken in neutral or two alternating emotional (i.e. angry and happy) prosody and the acoustically matched nonspeech hums. Mismatched Negativity, P3a and their associated neural oscillatory activities were analysed. Results showed that speech (relative to nonspeech) sounds produced greater and faster brain responses especially for anger compared to happiness. Anger also triggered greater brain responses than happiness for both speech and nonspeech during auditory change detection, but this emotion-specific effect was only preserved for speech and reversed for nonspeech during involutionary attentional orientation. Together, these findings showcase highly complex interactions between speech dominance and emotion specificity effects during different stages of pre-attentive processing. Our study provides evidence for the specialised mechanisms involved in emotional speech perception, which may have practical implications for understanding and treating clinical populations with altered speech sensitivity and emotion processing.