Diminished complexity of heart rate time series in adolescents facing negative events during everyday life

Physiological systems need to be flexible in order adapt a changing environment. Negative events, however, induce flexibility reductions that seem necessary for coping purposes. To date, studies have measured linear variability and entropy heart output, but none examined the scaling properties of cardiac system when individuals deal with stressful everyday events. This study was aimed at testing hypothesis complexity dynamics is diminished face negative events real life. Cardiac (linear) (nonlinear), as well discomfort effectiveness event-related emotion regulation (EER) were ecologically N = 65 adolescents (Mage 14.80 years; SDage 0.86; 55.38% girls). Repeated Measures MANOVAs revealed higher rate (HR) lower (higher long-term exponent, p .029; Fractal Dimension FD, .030; Sample Entropy, .001) during EER comparison non-emotion conditions (NER). Wilcoxon non-parametric tests Hurst exponents (p .006) than NER. No significant correlations found between variables although NER conditions, greater self-rated < .050). processes involved increases HR FD changes might reflect real-time scale’s predominance output are dealing Keywords: adolescence; regulation; complexity; variability; observational descriptive