Synchrony and concordance: A multilevel analysis of the effects of individual differences during a CO2 challenge

Emotion theories posit that emotion systems (e.g., behavior, self-report, physiology) should be related when an emotion is being elicited because this serves an adaptive purpose and allows the individual to respond appropriately to the present situation. Oftentimes, this coherent relationship is not found, and research has hypothesized that the type of analyses used and lack of examination of individual differences could be affecting this relationship. Most studies examine the relationship between emotion systems between-subjects when within-subjects analyses may be more appropriate. The present study examined the relationship between self-reported distress (SUDS) and heart rate, and whether trait differences of anxiety sensitivity and heart rate variability affect that relationship. Undergraduate students (N = 294) completed an anxiety sensitivity measure and their heart rate variability was calculated prior to undergoing a 7.5% CO2 challenge. SUDS was collected 11 times throughout the challenge and heart rate was collected continuously. Consistent with studies examining both concordance (between-subjects correlation between systems) and synchrony (within-subjects correlation between systems), synchrony was found between heart rate and SUDS, but concordance was not found between the two variables. Contrary to our hypotheses, neither anxiety sensitivity nor heart rate variability predicted synchrony between heart rate and SUDS. Our results suggest that synchrony is a more appropriate measure of adaptive emotional response than concordance because synchrony allows for examination of coordination of emotion systems over time