Responses to heartbeats in ventromedial prefrontal cortex contribute to subjective preference-based decisions

Abstract

Forrest Gump or Matrix? Choosing which movie you prefer is a subjective decision that entails self-reflection. While the neural underpinnings of valuation and choice have been extensively investigated, the contribution of self-related processes to subjective decisions has been largely overlooked. Self-related processes have been linked to a basic interoceptive biological mechanism, the neural monitoring of heartbeats, in particular in ventromedial prefrontal cortex (vmPFC), a region also involved in value encoding. We thus hypothesized a functional coupling between interoceptive self-related processes and the precision of value encoding in vmPFC. Human participants were presented with pairs of movie titles. They indicated either which movie they preferred, or performed a control objective visual discrimination that did not require self-reflection. Using magnetoencephalography, we measured heartbeat-evoked responses (HERs) before option presentation, and confirmed that HERs in vmPFC were larger when preparing to the subjective, self-related task. We retrieved the expected cortical value network during choice with time-resolved statistical modeling, and show that HERs before option presentation interacted in a multiplicative manner with value encoding during choice in vmPFC. The interaction was absent in the objective discrimination task, and could not be trivially explained neither by changes in cardiac activity nor by arousal fluctuations. The neural interaction between HERs and value encoding predicted preference-based choice consistency over time, accounting for both inter-individual differences and trial-to-trial fluctuations within individuals. Our results thus reveal a functional coupling in vmPFC between self-related interoceptive processes and subjective value encoding, which stabilizes the behavioral expression of long-term preferences.Significance statementDeciding whether you prefer Forrest Gump or Matrix is based on subjective values, which only you, the decision-maker, can estimate and compare, by asking yourself. Yet, how self-related processes influence subjective valuation is not known. We show that in ventromedial prefrontal cortex, an interoceptive self-related process, the neural response to heartbeats, influences the cortical representation of subjective value. The neural interaction between interoceptive self-related process and value encoding predicts choice consistency, i.e. whether you consistently prefer Forrest Gump over Matrix over time, thus contributing to the stable expression of long-lasting preferences that define, at least in part, our identity.

The function of consciousness is to generate experience

“…Subjective value is considered subjective only inasmuch as it is subject-dependent, as in whether one prefers Bordeaux vs. Bourgogne. In other words, most of the relevant research has emphasized value in and of itself, leaving its subjective aspect remains mostly unaddressed (but see Azzalini, Buot, Palminteri, & Tallon-Baudry, 2021). A recent trend in computational decision making relates value more directly to the internal state and intrinsic goals of the subject of experience: the value of a reward is computed as the distance between the current state and the state the agent would find herself in if she obtained the reward (Juechems & Summerfield, 2019; Keramati & Gutkin, 2014).…”

The influence of the respiratory cycle on reaction times in sensory-cognitive paradigms

“…The networks receiving external evidence and those serving interoception are intricately linked (Ondobaka et al 2017), and studies show that the homeostatic state and visceral body functions such as heartbeat bear an influence on perceptual reports. For example, the endocrine system can shape perceptual thresholds via levels of glucocorticoids (Obleser et al 2021), while the heartbeat affects perception not only in the somatosensory domain (Al et al 2020) but also influences value-based decisions (Azzalini et al 2020) and can guide visual exploration search (Galvez-Pol et al 2020). All in all, this supports the notion of active sensing, whereby the integration and exploitation of sensory information is controlled by a combination of external, intrinsic and metacognitive processes, which often operate on a seemingly rhythmic basis.…”

Active tactile discrimination is coupled with and modulated by the cardiac cycle

“…Increasing evidence suggests that ever-fluctuating interoceptive signals exert a putative effect over stimulus processing (Azevedo et al, 2017;Azzalini et al, 2019Azzalini et al, , 2021Garfinkel & Critchley, 2016;Rae et al, 2018). This work is often conceptualized within the predictive coding framework (Allen et al, 2019;Friston et al, 2017) to explain how the brain integrates interoceptive and exteroceptive information to optimise beliefs about the world.…”