Acute physical-activity related increases in interoceptive ability are not enhanced with simultaneous interoceptive attention.

Interoception, the sense of the internal body, is proposed to support self-regulation, and consequently influence mental health. Researchers have therefore shown interest in improving the ability to accurately monitor internal signals (i.e., interoceptive accuracy, IAcc). Research suggests that cardiac IAcc is modifiable by both manipulations of interoceptive attention (guided attention towards the internal body), and interoceptive exposure (strategically inducing somatic signals e.g., via physical activity). Whilst successful in isolation, it is unclear whether a combined approach (i.e., directing attention towards the internal body when signals are more salient) could elicit greater benefits. In a 2 × 2 within-subject design, 48 healthy adults (Mage = 25.98 ± 4.73 years, 50% female) completed four 20-min conditions varying in both attentional focus (interoceptive vs exteroceptive) and physical activity (active vs rest), with cardiac IAcc measured immediately after. Results revealed a main effect for physical activity (p < 0.001), however, there was no effect for attentional focus (p = 0.397), and no interaction effect (p = 0.797). Differential analyses showed that a higher sporting background increased sensitivity to physical activity-related increases in cardiac IAcc (p = 0.031). Findings indicate that (irrespective of attentional focus) moderate-vigorous physical activity-based interventions have the potential to increase cardiac IAcc, with certain individuals potentially benefiting more.

Relationship between cardiac cycle and the timing of actions during action execution and observation.

Previous research suggests that there may be a relationship between the timing of motor events and phases of the cardiac cycle. This relationship has thus far only been researched using simple isolated movements such as key-presses in reaction-time tasks and only in a single subject acting alone. Other research has shown both movement and cardiac coordination among interacting individuals. Here, we investigated how the cardiac cycle relates to ongoing self-paced movements in both action execution and observation using a novel dyadic paradigm. We recorded electrocardiography (ECG) in 26 subjects who formed 19 dyads containing an action executioner and observer as they performed a self-paced sequence of movements. We demonstrated that heartbeats are timed to movements during both action execution and observation. Specifically, movements were less likely to culminate synchronously with the heartbeat around the time of the R-peak of the ECG. The same pattern was observed for action observation, with the observer's heartbeats occurring off-phase with movement culmination. These findings demonstrate that there is coordination between an action executioner's cardiac cycle and the timing of their movements, and that the same relationship is mirrored in an observer. This suggests that previous findings of interpersonal coordination may be caused by the mirroring of a phasic relationship between movement and the heart.

Dissociation in How Core Autism Features Relate to Interoceptive Dimensions: Evidence from Cardiac Awareness in Children.

Interoception in autism is receiving increasing research attention. Previously, differences were identified in autism on both objective and subjective measures of interoception, and an association with anxiety. Yet, it is currently unknown how interoception relates to core autism features. Here, in 49 autistic children, we consider how interoceptive accuracy (measured with heartbeat detection tasks) and sensibility (subjective judgements of awareness) relate to overall severity on the Autism Diagnostic Observation Schedule, and symptom domains of social-affective and repetitive, restricted behaviors. Socio-affective features were related to interoceptive sensibility, while repetitive restricted behaviors were related to interoceptive accuracy. This dissociation suggests disparate interoceptive mechanisms for the formation and/or maintenance of autistic features.

The link between interoceptive processing and anxiety in children diagnosed with autism spectrum disorder: Extending adult findings into a developmental sample.

Anxiety is a major associated feature of autism spectrum disorders. The incidence of anxiety symptoms in this population has been associated with altered interoceptive processing. Here, we investigated whether recent findings of impaired interoceptive accuracy (quantified using heartbeat detection tasks) and exaggerated interoceptive sensibility (subjective sensitivity to internal sensations on self-report questionnaires) in autistic adults, can be extended into a school-age sample of children and adolescents (n = 75). Half the sample had a verified diagnosis of an Autism Spectrum Disorder (ASD) and half were IQ- and age-matched children and adolescents without ASD. The discrepancy between an individual's score on these two facets of interoception (interoceptive accuracy and interoceptive sensibility), conceptualized as an interoceptive trait prediction error, was previously found to predict anxiety symptoms in autistic adults. We replicated the finding of reduced interoceptive accuracy in autistic participants, but did not find exaggerated interoceptive sensibility relative to non-autistic participants. Nonetheless, the positive association between anxiety and interoceptive trait prediction error was replicated. However, in this sample, the best predictor of anxiety symptoms was interoceptive sensibility. Finally, we observed lower metacognitive accuracy for interoception in autistic children and adolescents, relative to their non-autistic counterparts. Despite their reduced interoceptive accuracy on the heartbeat tracking task and comparable accuracy on the heartbeat discrimination task, the autistic group reported higher confidence than the typical group in the discrimination task. Findings are consistent with theories of ASD as a disorder of interoceptive processing, but highlight the importance of validating cognitive models of developmental conditions within developmental populations.

Altering movement parameters disrupts metacognitive accuracy.

Correctly estimating the confidence we should have in our decisions has traditionally been viewed as a perceptual judgement based solely on the strength or quality of sensory information. However, accumulating evidence has demonstrated that the motor system contributes to judgements of perceptual confidence. Here, we manipulated the speed at which participants' moved using a behavioural priming task and showed that increasing movement speed above participants' baseline measures disrupts their ability to form accurate confidence judgements about their performance. Specifically, after being primed to move faster than they would naturally, participants reported higher confidence in their incorrect decisions than when they moved at their natural pace. We refer to this finding as the adamantly wrong effect. The results are consistent with the hypothesis that veridical feedback from the effector used to indicate a decision is employed to form accurate metacognitive judgements of performance.