Complexity of heart rate variability during moral judgement of actions and omissions

Abstract

Recent research strongly supports the idea that cardiac activity is involved in the organisation of behaviour, including social behaviour and social cognition. The aim of this work was to explore the complexity of heart rate variability, as measured by permutation entropy, while individuals were making moral judgements about harmful actions and omissions. Participants (N ¼ 58, 50% women, age 21-52 years old) were presented with a set of moral dilemmas describing situations when sacrificing one person resulted in saving five other people. In line with previous studies, our participants consistently judged harmful actions as less permissible than equivalently harmful omissions (phenomenon known as the "omission bias"). Importantly, the response times were significantly longer and permutation entropy of the heart rate was higher when participants were evaluating harmful omissions, as compared to harmful actions. These results may be viewed as a psychophysiological manifestation of differences in causal attribution between actions and omissions. We discuss the obtained results from the positions of the system-evolutionary theory and propose that heart rate variability reflects complexity of the dynamics of neurovisceral activity within the organism-environment interactions, including their social aspects. This complexity can be described in terms of entropy and our work demonstrates the potential of permutation entropy as a tool of analyzing heart rate variability in relation to current behaviour and observed cognitive processes.

Analytic and Holistic Thinkers: Differences in the Dynamics of Heart Rate Complexity When Solving a Cognitive Task in Field-Dependent and Field-Independent Conditions

“…From the physiological perspective, the primary origin of HRV is related to the activity of the autonomic nervous system through its sympathetic and parasympathetic parts (Thayer and Lane, 2009). Various cortical areas in the brain contribute to the regulation of heart rate (e.g., see review in Smith et al, 2017) and changes in HRV indexes during cognitive and socioemotional tasks are shown to correlate with some aspects of task performance (Kemp et al, 2010;Arutyunova et al, 2020;Hilgarter et al, 2021). Therefore, the analysis of HRV has become a popular noninvasive tool in psychophysiological studies (Laborde et al, 2017).…”

“…Variable changes in heart rate are viewed as a result of heart coordination with changes in the sets of activated neurons distributed across the cerebral cortex and subcortical structures and specialized in relation to particular behavior. Our previous studies (Bakhchina et al, 2018;Arutyunova et al, 2020) demonstrate that, out of existing and widely used HRV indexes, non-linear metrics, such as entropy measures, most accurately reflect changes in behavior and cognitive performance. Other authors also reported that non-linear HRV metrics (e.g., entropy and fractal dimension) are more informative for the studies of behavior than statistical and frequency measures of HRV (Pham et al, 2021).…”

“…Behavior acquired at earlier stages of development is more automated and intuitively implemented than newly formed behavior, and vice versa behavior acquired at later stages of development is more differentiated and detailed than earlier acquired behavior. Values of heart rate complexity observed during newer behavior are expected to be higher (Bakhchina et al, 2018;Arutyunova et al, 2020). Thus, comparative analyses of HRV entropy measures can be used to reconstruct the relative level of differentiation of the individual experience actualized during problem-solving.…”