Risk-taking behaviour

The environment we interact with constantly confronts us with challenges that may cause us potential harm or provide a reward depending on our choices. The ability to evaluate and weigh the trade-off between a potential win and a harmful loss is called risk-taking ability. This Thesis aims to better clarify some of the many unknown aspects regarding this function. As an index of real-life risk-taking tendencies, we chose to use the Balloon Analogue Risk Task (BART). This Thesis is divided into two chapters. The first chapter describes the effects on risk-taking behaviour of 2 techniques of vestibular stimulation: Caloric Vestibular Stimulation (CVS) and Galvanic Vestibular Stimulation (GVS). More in detail, contrary to our predictions, results in Study 1 show how the CVS can selectively increase risk tendencies only for bodily-related stimuli, implying that the CVS is not sufficient to modify risk-taking behaviour as a whole, but a biologically salient and bodily-related stimulus is necessary to allow the effects of the CVS on the representation of the body to interfere with the decision regarding dangerous situations. As a continuation, Study 2 directly deals with the influence of the vestibular input on risk-taking. To assess that, the BART is administered to subjects undergoing GVS. A significant reduction of hazardous tendencies is reported during L-GVS when compared with the opposite polarity, highlighting the vestibular contribution to high cognitive functions, risk-taking in particular, with a polarity specific effect that mainly excites the activity of the right hemisphere. In continuity with the previous, chapter 2 shows the effects on risk-taking of more ecological and natural tools. More precisely, Study 3 reports our findings regarding short-term alterations of the gravitational signals to the brain and how they influenced the willingness to take risks. Our results demonstrated an effect of head orientation on risk propensity, where an upright head position showed behavioural patterns directed towards more conservative and less risky choices compared to a downward head position (i.e. “bed rest”). A coherent and well-integrated vestibular input to the brain is needed to properly cope with different environmental situations. Lastly, Study 4 displays an attempt to detect possible changes in risk-taking after the prolonged time spent in isolation during the Covid-19 lockdown. No significant modification in risk tendencies was found as the time spent in isolation increased. Together, these results highlight the importance of a preserved ability to judge risk situations and have the ability to cope with challenging environments. In particular, the understanding of the neurocognitive substrates underpinning this function is of primary importance in order to begin to sort out the many unknown sides of this topic.