Electrocortical responses associated with attention bias to fearful facial expressions and auditory distress signals.

Understanding how emotional stimuli across auditory and visual sensory domains interact and influence multimodal attentional mechanisms is important to understanding how humans prioritize and isolate emotionally-laden stimuli in a continual stream of sensory information that occurs in everyday life. While multimodal emotional human-relevant stimuli have been used in the past, this study is one of the first to look at how human-generated threat-related sounds (e.g., screams) interact with human-generated visual cues of threat (fearful facial expressions) to determine whether these converging sources of threat are represented by either combined or isolated enhancements of visual attention as measured with event-related potential (ERP) components related to attention: the N170, N2, and N2pc. Using the dot-probe task, this study demonstrates that converging sources of multimodal audiovisual threat interact to modulate the N170 ERP component such that auditory distress signals widen the spotlight of attention beyond the contralateral enhancement elicited by the fearful face cue. Multimodal facilitation was neither observed on the N2pc nor the anterior N2. Rather, separate unimodal effects were observed on these ERP components.