Characterizing the Autonomic Correlates of Negative Emotion Differentiation: Bridging Laboratory and Daily Life Assessments.

Emotion differentiation reflects how well individuals make fine-grained distinctions between their emotions. Higher emotion differentiation, especially for negative emotion, is associated with a wide range of adaptive emotional responses and improved mental health, but the psychophysiological correlates of emotion differentiation remain underexplored. Here, we examined associations between negative emotion differentiation and autonomic nervous system (ANS) functioning at rest in a laboratory setting and across 3 days of ambulatory assessment in daily life. Participants were 80 trauma-exposed adults, half of whom met diagnostic criteria for a primary diagnosis of posttraumatic stress disorder. Measures of parasympathetic control on the cardiac system (i.e., respiratory sinus arrhythmia; RSA), sympathetic control on the cardiac system (pre-ejection period; PEP), and sympathetic control on the eccrine system (electrodermal activity; EDA) were collected. Measures of ANS functioning that reflect the relative influences of the parasympathetic and sympathetic nervous systems were assessed to index ANS functioning within the cardiac system (i.e., cardiac autonomic balance [CAB] and cardiac autonomic regulation [CAR]) and across the cardiac and eccrine systems (i.e., cross-system autonomic balance [CSAB] and cross-system autonomic regulation [CSAR]). After adjusting for relevant covariates, higher negative emotion differentiation was associated with increased RSA and PEP, reflecting greater ANS activity in the parasympathetic and sympathetic branches, respectively. However, these associations were inconsistent across settings, with relationships between negative emotion differentiation and PEP only found in the lab and relationships between negative emotion differentiation and RSA only found in daily life. More consistent across settings were associations between higher emotion differentiation and higher CAR, suggesting composite measures of ANS functioning might be more robust psychophysiological indicators of negative emotion differentiation. Findings clarify the psychophysiological correlates of negative emotion differentiation and contribute to our understanding of how negative emotion differentiation supports better emotion regulation and psychological functioning.