Abstract
<p>Flow, the state of absorption in an activity, has typically been assessed through retrospective self-reports. This method provides only a broad summary of the subjective experience and cannot capture its temporal dynamics as the experience develops. In our prior work (Genc et al., 2026), a real-time measurement approach was introduced, using a custom-designed foot pedal. Continuous pedal angle data served as a proxy for perceived flow, correlating with post-task Flow Short Scale (FSS) scores. The present study extends this method by examining the temporal dynamics of flow during 40-minute sessions of the virtual reality game Thumper. Participants (N = 35) continuously reported their perceived flow levels using the pedal while electrocardiogram (ECG) signals and game performance were recorded concurrently. Results provided further evidence for the validity of the method, with a positive association observed between pedal ratings and FSS-flow scores. Mixed-effects models predicting pedal angle from heart-rate variability (HRV) metrics revealed that high-frequency (HF)-HRV was a negative predictor, while the low-frequency (LF)/HF ratio showed no reliable association with pedal angle. A time sensitive cross-correlation analysis, however, identified relationships between both HRV metrics and pedal angle, highlighting parasympathetic activity and autonomic balance as physiological indicators that accompany flow experience. Finally, game performance was found to be a robust, positive predictor of flow at both game subleveles and second-by-second resolution. Taken together, these findings demonstrate that continuous measurement can capture temporal dynamics and physiological correlates of flow that retrospective assessment cannot.</p>