# Short-Term Effects of Heart Rate Variability Biofeedback on Working Memory

## TL;DR

A single session of heart rate variability biofeedback improves working memory and increases relaxation and attention, but not through changes in heart-related nerve activity.

## Contribution

This study demonstrates that a single HRVB session can enhance working memory and relaxation without affecting cardiac vagal tone.

## Key findings

- Working memory performance improved after HRVB, with higher correct responses in the N-back task.
- Participants reported increased serenity and attentiveness following HRVB.
- Improvements were not linked to changes in vagally mediated HRV measures.

## Abstract

Drawing upon the well-documented impact of long-term heart rate variability biofeedback (HRVB) on psychophysiological responses, this study seeks to explore the short-term effects arising from a single HRVB session during and after paced breathing exercise. The research aligns with the neurovisceral integration model, emphasizing the link between heart rate variability (HRV) levels and cognitive performance. Therefore, a randomized controlled trial employing a between-subjects design was conducted with 38 participants. Each participant was assigned to either the paced breathing intervention group or the spontaneous breathing control group. The study assessed various parameters such as cardiac vagal tone, evaluated through vagally mediated HRV measures, and working memory, measured using the N-back task. Additionally, participants’ affective states were assessed through self-reported questionnaires, specifically targeting attentiveness, fatigue, and serenity. The results notably reveal enhancements in the working memory task and an elevated state of relaxation and attention following the HRVB session, as evidenced by higher averages of correct responses, serenity and attentiveness scores. However, the findings suggest that this observed improvement is not influenced by changes in cardiac vagal tone, as assessed using a simple mediation analysis. In conclusion, this study presents promising insights into the impact of a single HRVB session, laying the foundation for future research advancements in this domain.

The online version contains supplementary material available at 10.1007/s10484-024-09624-7.