Loneliness as a Predictor of Blunted Heart Rate Variability Responses During Cognitive Demands

Loneliness has been linked to adverse health outcomes, yet little is known about how different temporal dimensions of loneliness—chronic and situational—relate to physiological flexibility during cognitive demands. This study examined whether chronic loneliness (past 5 years) and situational loneliness (past 24 h) predicted vagally mediated heart rate variability (vmHRV) reactivity across diverse cognitive tasks. Participants ( N = 151) completed attention, perception, short‐term memory, working memory, and executive function tasks while continuous electrocardiography was recorded. Linear mixed‐effects models revealed that higher chronic loneliness was robustly associated with blunted vmHRV reactivity across attention, perception, working memory, and executive function demands, indicating reduced cardiac vagal withdrawal. These associations persisted after adjusting for differences in depressive symptoms, anxiety, perceived stress, emotion regulation, structural social network characteristics, health behaviors, and demographic factors. Although situational loneliness showed weaker and less consistent associations, exploratory analyses suggested that concurrent elevations in chronic and situational loneliness may be linked to especially blunted vmHRV reactivity during working memory demands, supporting a potential additive burden of loneliness. These findings underscore the value of distinguishing between temporal dimensions of loneliness and highlight chronic loneliness as an independent correlate of disrupted neurovisceral regulation. Addressing persistent feelings of social disconnection may be important not only for psychological well‐being but also for maintaining physiological systems that support adaptive cognitive functioning and long‐term health.