Journal article

The hierarchically mechanistic mind: A free-energy formulation of the human psyche

Paul B Badcock, Karl J Friston, Maxwell JD Ramstead

Physics of Life Reviews | ELSEVIER | Published : 2019


This article presents a unifying theory of the embodied, situated human brain called the Hierarchically Mechanistic Mind (HMM). The HMM describes the brain as a complex adaptive system that actively minimises the decay of our sensory and physical states by producing self-fulfilling action-perception cycles via dynamical interactions between hierarchically organised neurocognitive mechanisms. This theory synthesises the free-energy principle (FEP) in neuroscience with an evolutionary systems theory of psychology that explains our brains, minds, and behaviour by appealing to Tinbergen's four questions: adaptation, phylogeny, ontogeny, and mechanism. After leveraging the FEP to formally define ..

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University of Melbourne Researchers


Awarded by Wellcome Trust

Funding Acknowledgements

This work is dedicated to Lucy Morrish for her essential contribution to these ideas. We are also indebted to Nicholas Allen, Luke Badcock, Axel Constant, Casper Hesp, Jakob Hohwy, Annemie Ploeger, and Samuel Veissiere for their valuable discussions and comments on the earlier drafts. K.J. Friston is supported by the Wellcome Trust (Principal Research Fellowship; Ref: 088130/Z/09/Z), and M.J.D. Ramstead by the Canada First Research Excellence Fund, awarded to McGill University for the Healthy Brains for Healthy Lives initiative, and the Social Sciences and Humanities Research Council of Canada.