Vestibular stimulation attenuates unrealistic optimism

Abstract

INTRODUCTION: Unrealistic optimism refers to the pervasive tendency of healthy individuals to underestimate their likelihood of future misfortune, including illness. The phenomenon shares a qualitative resemblance with anosognosia, a neurological disorder characterized by a deficient appreciation of manifest current illness or impairment. Unrealistic optimism and anosognosia have been independently associated with a region of right inferior frontal gyrus, the pars opercularis. Moreover, anosognosia is temporarily abolished by vestibular stimulation, particularly by irrigation of the left (but not right) ear with cold water, a procedure known to activate the right inferior frontal region. We therefore hypothesized that left caloric stimulation would attenuate unrealistic optimism in healthy participants. METHODS: Thirty-one healthy right-handed adults underwent cold-water caloric vestibular stimulation of both ears in succession. During each stimulation episode, and at baseline, participants estimated their own relative risk of contracting a series of illnesses in the future. RESULTS: Compared to baseline, average risk estimates were significantly higher during left-ear stimulation, whereas they remained unchanged during right-ear stimulation. Unrealistic optimism was thus reduced selectively during cold caloric stimulation of the left ear. CONCLUSIONS: Our results point to a unitary mechanism underlying both anosognosia and unrealistic optimism, and suggest that unrealistic optimism is a form of subclinical anosognosia for prospective symptoms. Results: Compared to baseline, average risk estimates were significantly higher during left-ear stimulation, whereas they remained unchanged during right-ear stimulation.Unrealistic optimism was thus reduced selectively during cold caloric stimulation of the left ear. Conclusions:Our results point to a unitary mechanism underlying both anosognosia and unrealistic optimism, and suggest that unrealistic optimism is a form of subclinical anosognosia for prospective symptoms.

Self-deception as affective coping. An empirical perspective on philosophical issues

“…The decrease of frontal lobe activation in conjunction with the increase in the dopamine system should lead to a neurobiological situation favoring self-deception to its maximum. Indeed, increased frontal lobe activation decreases unrealistic optimism and anosognosia, which can be considered forms of self-deception (Mckay et al, 2013). In other words, the more one's prefrontal cortex is activated, the less one deceives oneself; and the more dopamine transmission, the more one deceives oneself.…”

The Moving History of Vestibular Stimulation as a Therapeutic Intervention

“…In a similar vein, left cold CVS was shown to reduce the desirability of a product (Preuss et al, 2014b) and to attenuate unrealistic optimism (McKay et al, 2013). Overall, activation of the right hemisphere through left cold CVS lowers the mood and vice versa.…”

“…It remains to be seen how those structural connections translate to a more functional level. The hemispheric specific activation/deactivation pattern has been suggested to enhance or hinder specific lateralized brain processes (McKay et al, 2013;NollHussong et al, 2014;Preuss et al, 2014b) . On a smaller scale, vestibular stimulation influences neuro-transmitter release (for a discussion see Gurvich et al, 2013;Mast et al, 2014).…”

The Moving History of Vestibular Stimulation as a Therapeutic Intervention

“…The vestibular system is intrinsically multisensory because of its neuroanatomical connections and a vestibular percept is thus rarely experienced purely (Angelaki et al, 2009;Blanke, 2012;Ferrè et al, 2012). Moreover, it has been hypothesized that the vestibular system and emotional circuits overlap (Preuss et al, 2014a) or that CVS would target the inferior frontal gyrus, a region involved in unrealistic optimism (McKay et al, 2013). On an lower level, the medial vestibular nucleus located in the medulla oblongata is connected to different brain areas associated with nociception, sleep and arousal, homeostasis and eye movements (Horowitz et al, 2005).…”

“…Besides these positive effects on perceptual and cognitive processes, vestibular stimulation has been shown to decrease pain (Ferrè et al, 2013, see chapter 2.3) and -depending on the side of stimulationimprove affect control (Preuss et al, 2014a), alter mood (Winter et al, 2012) and decrease unrealistic optimism (McKay et al, 2013, see chapter 2.2). Moreover, there are some hints that vestibular stimulation has positive effects on sleep characteristics (see chapter 2.1.).…”