EXPRESS: The Sound of Fear: How Horror Soundtracks Shape Threat Perception of Emotional Faces

Music strongly shapes emotional perception, yet its influence on social threat evaluation remains underexplored. This study examined whether scary music biases threat perception of emotional faces using subjective ratings and pupillometry. In a within-subjects design, a predominantly female sample of participants viewed angry, neutral, and happy faces following either scary music or white noise. Behavioural ratings showed that faces were perceived as more threatening after scary music relative to white noise, consistent with affective priming accounts. Notably, the effect extended beyond angry and neutral faces to happy faces, suggesting that the pairing with fear-inducing music distorted their positive meaning, perhaps conveying ill-intent instead. Pupillometry results revealed no overall effect of scary music on pupil size, however, an interaction showed increased pupil dilation to neutral faces under scary music, consistent with the heightened susceptibility of ambiguous stimuli to priming. Angry and happy faces may have elicited sufficient arousal on their own, limiting additional music-related effects. These findings demonstrate that scary music biases threat perception both behaviourally and physiologically, though not uniformly across emotions. By showing that music can alter evaluation of socially meaningful stimuli (i.e., facial expressions), this study advances understanding of cross-modal affective priming and has implications for contexts where music may unconsciously shape social judgements.