Reduction of auditory input improves performance on the heartbeat tracking task, but does not necessarily enhance interoception

Abstract

Previous research utilising a between-subjects design indicates that the use of noise-dampening ear-protectors might enhance interoceptive accuracy (IAcc). In the present study, we further examined this effect using a repeated-measures, within-participants design, and investigated potential mechanisms that might explain the effect. 50 participants completed the heartbeat tracking task (HTT) with and without the use of ear-protectors, in a counter-balanced order. Participants were asked to count the number of heartbeats occurring in five discrete time intervals of 25, 35, 45, 55 and 95 seconds, without feeling for a manual pulse. HTT scores were significantly higher when ear-protectors were worn, and the improvement in performance was greatest for participants with lower baseline IAcc. Participants also performed more consistently across the five trials when wearing the ear-protectors. The ear-protectors were associated with significantly increased self-reported heartbeat audibility, concentration, and task-related confidence, and decreased levels of distractibility. Heartbeat audibility was also correlated with HTT performance when the ear-protectors were worn. The exteroceptive nature of the feedback from the ear-protectors therefore precludes the utility of this manipulation to assess causal hypotheses related to changes in IAcc. However, it may serve as a simple, non-invasive manipulation to assess the effects of externalised interoceptive signals. Highlights Ear-protectors elicit an improvement in performance on the heartbeat tracking task This improvement is greatest for participants with lower baseline accuracy The improvement is associated with the auditory perception of the heartbeat Prior use of ear-protectors did not result in later enhanced performance on the control condition without ear-protectors.