Physiological Harmony or Discord? Unveiling the Correspondence Between Subjective Arousal, Valence and Physiological Responses
Although affective state may occur almost inevitably together with physiological changes, it is still unclear whether events evoking similar affective experiences also produce comparable physiological responses or whether variation is the norm within individuals. To unravel this debate, we investigated the correspondence between physiological reactions and experienced arousal and valence, using representational similarity analysis. In two independent (Ns = 491 and 64) samples and three affect-inducing tasks, representational similarity matrices (RSMs) of skin conductance (SCR) and startle responses, as readouts of arousal and valence, respectively, were compared to RSMs of valence and arousal ratings that align with these competing theories. Furthermore, to address the role of intraindividual variability, we also investigated its influence on the relationship between physiological responses and experienced affect. We observed that dismissing vs considering intraindividual variability led to differential relations with models of valence and arousal, but models assuming variation proofed to be more representative of individual physiological patterns. Importantly, we observed strong to decisive evidence for a correspondence between SCR and startle responses and models of arousal and valence that assume variation, especially between trials evoking higher amplitude responses. These results emphasize the importance of considering intraindividual variability to assess the affect-physiology relationship (and in psychophysiology research in general) and invite to reconsider the notion of physiological reactivity as a potential indicator of affective states, prompting a shift towards understanding the mechanisms through which physiological changes contribute to conscious affective experiences.