Psychophysical identity and free energy

Alex Kiefer

Research output: Contribution to journalArticleResearchpeer-review

21 Citations (Scopus)


An approach to implementing variational Bayesian inference in biological systems is considered, under which the thermodynamic free energy of a system directly encodes its variational free energy. In the case of the brain, this assumption places constraints on the neuronal encoding of generative and recognition densities, in particular requiring a stochastic population code. The resulting relationship between thermodynamic and variational free energies is prefigured in mind-brain identity theses in philosophy and in the Gestalt hypothesis of psychophysical isomorphism.

Original languageEnglish
Number of pages9
JournalJournal of the Royal Society Interface
Issue number169
Publication statusPublished - 1 Aug 2020


  • free energy
  • thermodynamics
  • variational inference

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