Intuitive Risk Perception : a Neuroscientific Approach

Abstract

Recent theoretical models of risk perception emphasize the role of intuitive and affective processes. Empirical evidence, however, remains scarce. In the present dissertation event-related brain potentials (ERP) are used as a sensitive tool to shed light on the role of intuition in health risk perception. Three studies are presented in which participants viewed pictures of unknown persons in the context of a HIV (Human Immunodeficiency Virus) risk perception paradigm while ERPs were recorded. This strategy enabled the demonstration of key processing characteristics of intuition: speed, affective evaluation, and implicitness. In the first study, participants judged the HIV risk of 120 persons based on facial appearance. Results showed enlarged positive brain potentials for risky faces in a time window from 350 - 650 ms. The second study added important evidence by showing that these results are not confined to facial stimuli. Using naturalistic photographs of real persons that resemble real life encounters and pictures used on internet dating platforms, it was established that risky persons prompt larger LPPs (late positive potentials), starting after approximately 300 ms. Based on the results of these two studies it is concluded that HIV risk of unknown persons is assessed intuitively. Discriminating among risky and safe stimuli in a split second provides strong evidence for intuitive processing regarding the key characteristic of speed. Furthermore, both studies provided supportive evidence for affective evaluation, another hallmark feature of intuitive processing. Risky stimuli were associated with enlarged LPPs, a component known to be sensitive to the intrinsic affective relevance of stimuli. The third study incorporated an implicit condition, allowing risk-related processing differences to be assessed in the absence of external task demands pertaining to HIV risk judgment. By showing that ERPs from the implicit condition - obtained during a quick glimpse and with no intention to evaluate risk - are related to later reports of HIV risk, these results provide strong evidence for the intuitive and incidental character of risk perception, another key feature of intuition. Moreover, ERP results from a subsequent explicit condition replicated previous findings, providing additional evidence for the intuitive features of speed and affective evaluation.Considering previous findings in affective neuroscience, it is proposed that persons judged as risky already attain a higher saliency early on during information processing and guide selective attention processes. These findings have implications for theoretical models of health risk perception and point to intuitive influences in everyday health risk perception.