Minimal physicalism as a scale-free substrate for cognition and consciousness

Abstract

Theories of consciousness and cognition that assume a neural substrate automatically regard phylogenetically basal, nonneural systems as nonconscious and noncognitive. Here, we advance a scale-free characterization of consciousness and cognition that regards basal systems, including synthetic constructs, as not only informative about the structure and function of experience in more complex systems but also as offering distinct advantages for experimental manipulation. Our “minimal physicalist” approach makes no assumptions beyond those of quantum information theory, and hence is applicable from the molecular scale upwards. We show that standard concepts including integrated information, state broadcasting via small-world networks, and hierarchical Bayesian inference emerge naturally in this setting, and that common phenomena including stigmergic memory, perceptual coarse-graining, and attention switching follow directly from the thermodynamic requirements of classical computation. We show that the self-representation that lies at the heart of human autonoetic awareness can be traced as far back as, and serves the same basic functions as, the stress response in bacteria and other basal systems.

Neurons as hierarchies of quantum reference frames

“…Motivated in part by recent analyses showing that cellular bioenergetic resources fall orders of magnitude short of those needed for fully-classical computation at macromolecular scales [63], here we adopt a quantum-theoretic perspective from the start. This perspective allows full use of the quantum information toolkit, including the concept of a QRF; it offers the advantages of full generality and applicability at any scale [50].…”

“…(1) assures compliance with Landauer's Principle [65,66,67], i.e. assures that the per-bit free-energy cost of classical bit erasure is paid on each cycle (see [44,50] for discussion). Figure 1: A holographic screen B separating systems A and B with an interaction H AB given by Eq.…”

“…"Timestamping" here can be considered merely to be imposition of an order on the recorded data; a separate, observation independent clock is not assumed (cf. [50] for a general discussion of time QRFs). As compliance with Eq.…”

“…We begin in §2 by briefly reviewing the implementation of QRFs by generic quantum systems [46,47,48] and their representations by CCCDs. We then turn to biological systems, reviewing the representation of simple homeostatic setpoints as QRFs [49,50] and extending this treatment to perisynaptic processes in neurons in §3. This allows us in §4 to represent the hierarchical structures of dendrites as hierarchical QRFs that detect the states -activity patterns -of particular "objects" -spatially-organized aggregates of presynaptic axon terminals -in their microenvironments.…”

Towards the Idea of Molecular Brains

“…Today, these “first wills” have spread, since the origins, to all scales of life and understanding “what bacteria want?” [ 114 ] would help to decipher the interplay between the “desire” to survive and the early stages of cell behaviour. One of the most basic forms of behaviour may be the distinct perception of the internal and external world, with the corollary ability to differentiate clearly between the self, other living beings and the physical world [ 115 , 116 , 117 ]. These faculties are shared at all scales of life: while the sense organs of metazoans are dedicated to the perception of stimuli of all kinds, unicellular beings have numerous sensors that perform an equivalent function but at the micro and nanoscopic scales.…”