What shared responses reveal about audience behavior: neural prediction and the emerging potential of peripheral synchrony

Predicting audience responses to dynamic media remains a significant challenge in neuromarketing and neuroforecasting. Intersubject correlation (ISC) has been proposed to address this need by quantifying the temporal similarity of neural, physiological, and behavioral responses among individuals exposed to the same stimulus. This narrative mini-review examines how ISC relates to preferences, judgments, and behavior and proposes a conceptual framework for interpreting its predictive value. Across modalities, ISC consistently reflects shared stimulus processing and is associated with attention, alongside additional links to engagement, memory, and higher-order narrative processing. Neural ISC has shown associations with individual, group, and population-level outcomes, although findings vary by neural modality, analytic approach, and behavioral endpoint. Peripheral ISC derived from gaze, heart rate, electrodermal activity, and facial expressions provides complementary information about interindividual alignment, but direct evidence for predicting consumer outcomes remains limited. At the same time, neural and peripheral measures capture various aspects of shared response dynamics, and combining them in a multimodal ISC approach may help distinguish synchronization in different functional domains, including perceptual, attentional, autonomic, affective, and valuation-related processes, and clarify their relationship to the target outcome. The proposed framework therefore conceptualizes ISC as a probabilistic predictor whose predictive value depends on which functional processes underlie the observed synchrony and their relevance to the specific outcome of interest.