Reviewing Physiological Measures of Implicit Consumer Response to Food

This review provides information about the contribution of the different physiological and neural methods of measuring consumer responses to food and discusses their potential for improving the understanding of processes underlying food pleasure and choice. A substantial body of work (132 studies published between 2011 and 2026) has recorded consumers' implicit responses to foods, using physiological (ANS) methods such as Galvanic Skin Response (GSR), Heart Rate (HR), Pupil Size (PS), and facial expressions; and neuronal methods such as Electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI). Autonomic Nervous System (ANS) indicators (GSR, HR, and PS) are activated during smelling or eating, with variations across products, likely reflecting the role of the ANS in the anticipatory and alert mechanisms of the body in response to food. However, the analysis of its relationship with explicit liking showed discrepancies depending on the study (product, protocol, context), indicating that they provide information about consumers' reactions that are different from those explicitly reported. Neuronal measures show differences in brain activity in response to foods, with fMRI identifying regions such as the Orbitofrontal Cortex and Somatosensory Cortex in response to foods. Integration of self-report assessment, implicit behaviour, physiological, and neural responses may provide a deeper understanding of the neural pathways linking sensory perception, autonomic activation, consumer decisions, and food-related pleasure.