Identifying Anger Emotion Using BVP Sensor: Heart Rate Variability (HRV)

Background: Accurate measurement tools are crucial for the early detection of emotional problems and dysregulation. Objectives: This study aimed to identify the emotion of anger using heart rate variability (HRV) as a biomarker. The diagnostic accuracy of five HRV-related subscales — HR, RR, HF, LF, and LF/HF — was evaluated among individuals with high and low anger. Methods: This descriptive (exploratory) quantitative study included adults aged 20 - 45 years living in Tehran. A total of 100 participants were initially recruited, but 24 were excluded due to insufficient or inaccurate HRV recordings, leaving a final sample of 76. Participants completed the Positive and Negative Affect Schedule (PANAS), and HRV data were collected via a blood volume pulse (BVP) sensor. Descriptive statistics and independent-sample t-tests were performed using SPSS, while receiver operating characteristic (ROC) and sensitivity analyses were conducted using MedCalc. Results: Significant differences were found between high- and low-anger groups in HR (P < 0.05) and RR (P < 0.001) scales, with higher mean scores in the high-anger group. Among the five HRV subscales, the RR scale had the highest discriminative accuracy (AUC = 0.71), performing significantly better than HR, HF, LF, and LF/HF. Conclusions: Heart rate variability, particularly the RR subscale, can serve as a reliable biological indicator for anger detection. These findings support the potential application of physiological markers in identifying emotional states.