Cross-modal social attention differs across emotional categories: Evidence from biological motion and gaze cues.

Humans are highly proficient at utilizing various social cues (e.g., biological motion, eye gaze) to guide their attention, even in the detection of stimuli from other modalities, a process known as cross-modal social attention. Here, we investigated whether this fundamental cross-modal social attention could be altered by the emotional information expressed in visual social cues. By presenting emotional (happy and sad) and neutral biological motion (BM) stimuli together with auditory targets in the modified central cueing paradigm, we found that happy BM cues induced a significantly stronger cross-modal attentional effect than neutral and sad ones. Moreover, this cross-modal modulation effect is similarly obtained with attentional effects induced by another type of social signal (i.e., gaze). Importantly, when the emotional information contained in visual social cues (i.e., BM, eye gaze) was disrupted through inversion, this modulation effect vanished, ruling out the potential confound of low-level features. Drift diffusion model (DDM) analysis showed that this effect was primarily associated with shorter non-decision time induced by happy cues (potentially reflecting preparatory attention), rather than with changes in the evidence accumulation rate (potentially reflecting sustained attentional resource allocation). Overall, these findings highlight the flexibility of cross-modal social attention to vary as a function of emotional categories. This cross-modal emotional modulation appears to involve preparatory attentional processing and is observed across perceptually distinct dynamic social signals (i.e., BM, eye gaze), suggesting a similar cognitive mechanism through which emotion perception interacts with cross-modal social attention.