Greater intra-individual variability in cardiac vagal control across task conditions was significantly associated with stronger stress-related decreases in response inhibition (r = -0.45).
Observational (n=25)
Randomly counterbalanced order of conditions
Is intra-individual variability in vagal control associated with response inhibition under stress in U.S. Army Soldiers?
Greater intra-individual variability in vagal control is associated with stronger stress-related decreases in response inhibition, suggesting a link between autonomic flexibility and adaptive cognition under stress.
Effect estimate: r = -0.45
p-value: p=0.026
Dynamic intra-individual variability (IIV) in cardiac vagal control across multiple situations is believed to contribute to adaptive cognition under stress; however, a dearth of research has empirically tested this notion. To this end, we examined 25 U.S. Army Soldiers (all male, Mean Age= 30.73, SD = 7.71) whose high-frequency heart rate variability (HF-HRV) was measured during a resting baseline and during three conditions of a shooting task (training, low stress, high stress). Response inhibition was measured as the correct rejection of friendly targets during the low and high stress conditions. We tested the association between the standard deviation of HF-HRV across all four task conditions (IIV in vagal control) and changes in response inhibition between low and high stress. Greater differences in vagal control between conditions (larger IIV) were associated with higher tonic vagal control during rest, and stronger stress-related decreases in response inhibition. These results suggest that flexibility in vagal control is supported by tonic vagal control, but this flexibility also uniquely relates to adaptive cognition under stress. Findings are consistent with neurobehavioral and dynamical systems theories of vagal function.
Spangler et al. (Tue,) conducted a observational in Healthy U.S. Army Soldiers (n=25). Intra-individual variability in cardiac vagal control vs. Low intra-individual variability was evaluated on Change in response inhibition (correct rejections) between low and high stress conditions (r = -0.45, p=0.026). Greater intra-individual variability in cardiac vagal control across task conditions was significantly associated with stronger stress-related decreases in response inhibition (r = -0.45).