(PS1-46) Exploring Patterns of Heart Rate Variability and State Anxiety Across The Trier Social Stress Task

Abstract Text: Heart rate variability (HRV), which quantifies the fluctuation in time between heartbeats, is a non-invasive measure of autonomic nervous system activity. Reduced HRV, measured at rest, is consistently observed in individuals with anxiety disorders compared to healthy controls and is thought to reflect diminished adaptability to stress. However, findings are mixed on whether HRV is modulated in real-time during social-evaluative stress and few studies have explored whether fluctuations reliability correspond to self-reported state anxiety. Further examination of HRV and state anxiety patterns during social stress is needed to better understand how physiological responses relate to psychological symptoms in social anxiety. We examined HRV and state-anxiety before, during, and after a social stress task. We hypothesized that both HRV and state anxiety would follow a quadratic trend, with HRV decreasing and state anxiety increasing during the stress task, followed by a rebound in both variables in the post-task phase. Participants completed the Trier Social Stress Test (TSST), while wearing a Polar H10 chest strap to record electrocardiogram (ECG) data. The task consisted of three phases: baseline, stress (giving a speech and solving math problems in front of an audience), and a post-stress phase. We calculate HRV using the root mean squared of successive differences (RMSSD), which measures the average differences between each successive heartbeat. RMSSD was computed separately for each phase. Additionally, participants completed the State-Trait Anxiety Inventory at the beginning of each phase to assess their current state anxiety. We conducted contrast analysis to examine the quadratic trend in HRV across the TSST. As hypothesized, we found a significant quadratic effect (F(1,39)=7.79), p< 0.01), indicating that HRV followed a parabolic pattern throughout the task. For state anxiety, we found a positive linear effect (F(1, 27)=1.25), p< 0.01), with anxiety increasing across all phases. Furthermore, we observed a significant relationship between state anxiety recovery (STAI measured before stress - STAI measured after stress) and HRV, such that poorer recovery was associated with lower HRV during the stress phase (r = -0.77, p < 0.05). Results suggest that HRV mirrors the change in state anxiety from baseline to stress phases with HRV decreasing and anxiety increasing as expected. However, during the post-task phase, HRV rebounded to baseline while state anxiety remained elevated suggesting that self-reported anxiety may lag behind physiological recovery. Moreover, lower HRV was associated with poorer anxiety recovery following the stress task. These results provide preliminary evidence that HRV may serve as a physiological measure of anxiety in response to social-evaluative stress.