Neuroadaptive retailing: Integrating multisensory biometrics and predictive emotion modelling to decode consumer immersion in hybrid shopping environments

Hybrid shopping environments—where digital and physical touchpoints merge—have transformed consumer engagement. Yet current retail strategies rarely adapt in real time to consumers' neuro-emotional states grounded in established theoretical frameworks. Drawing on the Stimulus-Organism-Response (S-O-R) model and affective computing theory, this study introduces the Neuroadaptive Retailing Index (NRI), a novel metric capturing the dynamic synchrony between consumers' neural, physiological, and visual responses and the adaptive stimuli of retail interfaces. NRI operationalizes neuroadaptive coherence—the degree to which multimodal biometric signals converge to reflect adaptive emotional resonance with environmental cues—as a measurable construct of immersive alignment. A controlled mixed-reality experiment integrated electroencephalography (EEG), galvanic skin response (GSR), eye-tracking, and facial-emotion analytics across 90 participants recruited through verified consumer research panels exposed to immersive phygital retail scenes. Predictive emotion modelling (PEM) quantified moment-to-moment affective trajectories, forming the basis for NRI computation using empirically derived regression weights (w1 = 0.42, w2 = 0.35, w3 = 0.23) that maximize prediction of self-reported immersion (R2 = 0.76). NRI scores reliably distinguished high-immersion environments characterized by congruent sensory cues and responsive design (Cohen's d = 1.34, 95% CI [0.98, 1.70]). Positive synchrony between neural engagement and gaze stability predicted purchase intent with 84% accuracy. Quadratic regression analysis confirmed gender- and modality-specific asymmetries and revealed adaptive design thresholds critical for consumer comfort (optimal adaptivity density: 12–18 micro-adjustments/minute; β_quadratic = −0.42, p < 0.001). Manipulation checks validated participant perception of adaptivity differences (t = 8.91, p < 0.001). The study received institutional ethics approval, and all participants provided informed consent for biometric data collection following GDPR-compliant protocols. Findings establish NRI as a diagnostic tool for retailers to engineer real-time adaptive experiences, inform service interface optimization, and advance consumer neuroscience methodology. The study reframes consumer immersion as an adaptive system state—characterized by neural-affective resonance rather than stimulus intensity—advancing both the theoretical understanding of experiential retail and the methodological integration of multisensory biometric analytics.