Frontal alpha asymmetry and heart rate variability as markers of conditional heart-brain interaction in test anxiety

Test Anxiety (TA) is known to impair the heart-brain interaction affecting both the central and autonomic nervous systems. The impairment is often assumed to be uniform, overlooking individual variability in stress response. This study explores how heart-brain dysregulation in TA may manifest conditionally, shaped by individual differences. Frontal alpha asymmetry (FAA), reflecting predisposition to avoidance and anxiety, and heart rate variability (HRV), indicating regulatory capacity, are employed as markers to examine individual variations. Fifty-seven healthy university students (M = 22.07 ± 2.61 years) participated in a 30-minute mock test before their university assessment, during which TA, avoidance, FAA, and HRV metrics were recorded. A moderated mediation model was then utilized to examine the relationship between heart-brain interaction and avoidance in test anxiety, testing for the conditionality of this interaction. While the overall moderated mediation model was non-significant, significant direct and indirect effects of HRV metrics on avoidance were observed at higher negative FAA values (B = 0.8805, p < 0.05). In contrast, at higher FAA levels, the indirect effect diminishes, and neither FAA (Estimate = 1.8565, p = 0.3559) nor its interaction with tonic RMSSD (Estimate = -0.3153, p = 0.3919) significantly predicts avoidance, suggesting reduced reliance on autonomic regulation. Results highlight that heart-brain impairment in TA is conditional, manifesting specifically in individuals with a predisposition to anxiety (negative FAA). The findings further suggest that a baseline disposition to anxiety can override the heart's regulatory activation in a stress response. While previous works suggest general heart-brain impairment, this study specifies that such impairment is primarily observed in individuals with a predisposition to anxiety.