Influence of an Interoceptive Training on Delay Discounting of Hypothetical Money and Food

This study investigated the impact of an interoceptive training on delay discounting of hypothetical monetary and food rewards. Delay discounting refers to the tendency to prefer immediate, smaller rewards over larger, delayed ones. Previous literature suggests that interoception, i.e. the conscious perception of internal bodily signals, could influence decision-making processes. Thus, this research proposed that an interoceptive training, consisting of a prolonged version of the heartbeat counting task, could influence delay discounting. Specifically, the interoceptive training was hypothesised to enhance awareness of internal physiological signals, thus reducing delay discount rates. To test this hypothesis, N = 51 participants were divided into two groups: an experimental group that performed the interoceptive training and a control group that performed a control task (i.e. focusing on external cues) before completing two delay discounting tasks. One task involved monetary rewards and one task involved food rewards, administered in a counterbalanced order within participants. Results of a repeated-measure analysis of variance indicated a significant interaction between reward type and group. Unlike the control group, which had the typical higher discount rates for food compared to money, the experimental group had discount rates more similar between reward types. Specifically, the experimental group showed reduced discount rates for food. Independent samples t-tests confirmed that there were no significant differences between groups on several relevant measures, including interoceptive accuracy and sensibility, hunger level at the time of testing, and trait impulsivity, ensuring that these variables did not influence the observed differences in 5 delay discounting. These results suggest that an interoceptive training can potentially moderate the usual high propensity to devalue future edible rewards. These findings underscore the potential of interoception-focused interventions to influence food-related decisions, suggesting that heightened attention to internal states may help mitigate impulsive behaviour. Keywords: Delay discounting, Food reward, Heartbeat counting task, Impulsivity, Interoception, Interoceptive training, Intertemporal choice, Monetary reward