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 the HMM across different spatiotemporal scales, we conclude by exploring its implications for theorising and research in the sciences of the mind and behaviour.

Key words: active inference, evolutionary systems theory, hierarchically mechanistic mind, free-energy principle, neuroscience, psychology

Excerpt: Recent work has begun to apply embodied and enactivist approaches to understanding mental disorders (Colombetti 2013; Fuchs 2009; Fuchs and Schlimme 2009; Zatti and Zarbo 2015). We believe that cultural psychiatry stands to gain a great deal from these new paradigms. This chapter will outline an approach to the cultural neurophenomenology of mental disorders that focuses on the interplay of culturally shaped developmental processes and modes of neural information processing that are reflected in embodied experience, narrative practices that are structured by ideologies of personhood, culturally shared ontologies or expectations, and situated modes of enactment that reflect social positioning and selffashioning. Research on metaphor theory suggests ways to connect the approaches to embodiment and enactment in cognitive science with the rich literature on the cultural shaping of illness experience in current medical and psychological anthropology. The resulting view of cultural enactment has broad implications for psychiatric theory, research, and practice, which we will illustrate with examples from the study of the phenomenology of delusions.

Open peer commentary on the article “A Moving Boundary, a Plastic Core: A Contribution to the Third Wave of Extended-Mind Research” by Timotej Prosen. Abstract: We argue that the free-energy principle (FEP) can indeed be used to articulate a conception of the boundaries of cognitive systems that meets the desiderata of third-wave extended-mind research. We point out that Markov blankets under the FEP definitionally constitute the means through which internal and external states are coupled, and so do not isolate systems from their environment. We argue that the nested, multiscale boundaries of the FEP formulation are indeed plastic and open to re-negotiation. Finally, we appeal to the formulation of niche construction under the FEP to argue that the extension of cognitive boundaries in this formulation is both synchronic and diachronic.

The aim of this article is to clarify how best to interpret some of the central constructs that underwrite the free-energy principle (FEP) – and its corollary, active inference – in theoretical neuroscience and biology: namely, the role that generative models and variational densities play in this theory. We argue that these constructs have been systematically misrepresented in the literature, because of the conflation between the FEP and active inference, on the one hand, and distinct (albeit closely related) Bayesian formulations, centred on the brain – variously known as predictive processing, predictive coding or the prediction error minimisation framework. More specifically, we examine two contrasting interpretations of these models: a structural representationalist interpretation and an enactive interpretation. We argue that the structural representationalist interpretation of generative and recognition models does not do justice to the role that these constructs play in active inference under the FEP. We propose an enactive interpretation of active inference – what might be called enactive inference. In active inference under the FEP, the generative and recognition models are best cast as realising inference and control – the self-organising, belief-guided selection of action policies – and do not have the properties ascribed by structural representationalists.

Key words: active inference, free-energy principle, representationalism, enactivism, structural representations

We present a multiscale integrationist interpretation of the boundaries of cognitive systems, using the Markov blanket formalism of the variational free energy principle. This interpretation is intended as a corrective for the philosophical debate over internalist and externalist interpretations of cognitive boundaries; we stake out a compromise position. We first survey key principles of new radical (extended, enactive, embodied) views of cognition. We then describe an internalist interpretation premised on the Markov blanket formalism. Having reviewed these accounts, we develop our positive multiscale account. We argue that the statistical seclusion of internal from external states of the system – entailed by the existence of a Markov boundary – can coexist happily with the multiscale integration of the system through its dynamics. Our approach does not privilege any given boundary (whether it be that of the brain, body, or world), nor does it argue that all boundaries are equally prescient. We argue that the relevant boundaries of cognition depend on the level being characterised and the explanatory interests that guide investigation. We approach the issue of how and where to draw the boundaries of cognitive systems through a multiscale ontology of cognitive systems, which offers a multidisciplinary research heuristic for cognitive science.

Key words: boundaries of cognition, variational free energy principle, externalism, internalism, enactive cognition, embodied cognition, markov blankets.