The Effects of Caloric Vestibular Stimulation on Risk-Taking Propensity and Interoception in Healthy Participants

Studies on risk-taking propensity have demonstrated the important role of our vestibular system (VS) when it pertains to decision making by mainly using galvanic vestibular stimulation (GVS). Studies have also shown the part that the VS plays in interoception. In this paper, we conduct an experiment using Caloric Vestibular Stimulation (CVS) to investigate the effects it may have on healthy participants’ risk-taking propensity, which we measure using the Balloon Analogue Risk Task (BART) expecting CVS to decrease risk-taking behavior. We also look into the effects of CVS on participants’ interoceptive accuracy and awareness using the Heartbeat Counting Task (HCT) expecting CVS to increase interoception. Moreover, we explore the possible correlations between proneness to both anxiety and depression with interoception, measured by HCT and the Multidimensional Assessment of Interoceptive Awareness Version 2 (MAIA-2), and risk-taking propensity. Our results initially showed no significant effect of CVS vs sham on the BART performance, but further analysis shows us a significant effect of the condition order (CVS first vs sham first) on the BART scores. We observe no significant results for the effect of CVS on HCT, but we see some significant correlations between subscales of the MAIA-2 and anxiety, depression, and BART performance. These results not only confirm what we knew about the effects of vestibular stimulation on risk-taking propensity and, to some extent, interoception, but also demonstrate a possibly varying effect, and thus different experimental condition requirements, between stimulations delivered through GVS and CVS. Keywords: Risk taking propensity, caloric vestibular stimulation, vestibular system, interoception, anxiety, depression, Balloon Analogue Risk Task, Heartbeat Counting Task, Multidimensional Assessment of Interoceptive Awareness Version 2