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

Heliyon. 2020. Vol. 6. No. 11. P. e05394.

Arutyunova K. R., Bakhchina A. V., Sozinova I. M., Alexandrov Y.

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.

Keywords: complexity, heart rate variability, Moral judgement, Neurovisceral integration, Permutation entropy