[P2] Poster: Day 2

[P2-21] Cardiac Rhythms, Interoception and Temporal Counting: Dynamic Interactions across Time Ranges

*Mai Sakuragi^1,2, Elisa M. Gallego Hiroyasu^1,2, Satoshi Umeda¹ (1. Keio University (Japan), 2. Japan Society for the Promotion of Science (Japan))

Keywords:

Time Perception,Heart Rate,Interoception,Dynamic Time Warping

While previous research has established links between heart rate variability over fixed time periods and interoception (perception of bodily responses) with time perception, the relationship between beat-to-beat cardiac activity patterns and actual counting timing remains unexplored. This study investigated how individual heartbeat interval time-series relate to temporal counting intervals across different time ranges. Seventy healthy participants performed time estimation tasks for three durations (23, 40, and 56 seconds) while cardiac activity was monitored. Individual counting intervals were estimated from variability in task performance across trials. Trial-by-trial heart rate and Dynamic Time Warping (DTW) distances between heartbeat intervals and estimated temporal counting intervals were calculated. Additionally, interoceptive accuracy was assessed using the heartbeat counting task. Results revealed time condition-specific relationships between cardiac activity and time perception: in the 23-second condition, higher average heart rate was associated with reduced variability in temporal counting intervals. In the 56-second condition, larger DTW distances between cardiac and counting time-series predicted better timing accuracy, indicating that greater divergence between cardiac and temporal counting rhythms enhanced time perception performance. Interoceptive accuracy showed weak positive correlation trends with timing performance in shorter durations, but this trend weakened in the 56-second condition. These findings demonstrate that while bodily arousal, interoception and temporal regularity are closely linked in shorter time conditions, divergence between cardiac and temporal counting rhythms becomes advantageous for accurate time perception in longer durations. This beat-to-beat time-series analysis approach revealed that optimal relationships between cardiac activity and time perception adaptively change according to the estimated time length.