Loneliness, cognitive task type, and heart rate variability in the Midlife in the United States (MIDUS) study

Some recent research suggests that loneliness may influence cardiovascular health by impacting heart rate variability (HRV), an important and commonly used indicator of parasympathetic nervous system functioning. The present study aims to investigate how task type and loneliness are associated with resting HRV and HRV reactivity following a Stroop and a mental arithmetic task in a national sample from the United States. Results showed that task type was a significant predictor of HRV reactivity. Specifically, the Stroop task elicited greater HRV decreases than the mental arithmetic task. These results suggest that the Stroop task may be a more sensitive task for detecting parasympathetic nervous system activation than the mental arithmetic task. Loneliness was not associated with resting HRV after controlling for demographic and clinical covariates. Higher loneliness was associated with greater decreases in HRV from baseline to Stroop, but only when Stroop was completed as the second task. Future research should examine the link between HRV reactivity and cardiovascular health across different age groups, taking into account variability brought about by different cognitive tasks and their contexts.