@Soupie
Anil Seth
The Cybernetic Bayesian Brain
available as PDF
Is there a single principle by which neural operations can account for perception,
cognition, action, and even consciousness? A strong candidate is now taking
shape in the form of “predictive processing”. On this theory, brains engage in predictive
inference on the causes of sensory inputs by continuous minimization of
prediction errors or informational “free energy”. Predictive processing can account,
supposedly, not only for perception, but also for action and for the essential contribution
of the body and environment in structuring sensorimotor interactions. In
this paper I draw together some recent developments within predictive processing
that involve predictive modelling of internal physiological states (interoceptive inference),
and integration with “enactive” and “embodied” approaches to cognitive
science (predictive perception of sensorimotor contingencies). The upshot is a development
of predictive processing that originates, not in Helmholtzian perception-
as-inference, but rather in 20th-century cybernetic principles that emphasized
homeostasis and predictive control. This way of thinking leads to (i) a new view of
emotion as active interoceptive inference; (ii) a common predictive framework linking
experiences of body ownership, emotion, and exteroceptive perception; (iii)
distinct interpretations of active inference as involving disruptive and disambiguatory—
not just confirmatory—actions to test perceptual hypotheses; (iv) a neurocognitive
operationalization of the “mastery of sensorimotor contingencies” (where
sensorimotor contingencies reflect the rules governing sensory changes produced
by various actions); and (v) an account of the sense of subjective reality of perceptual
contents (“perceptual presence”) in terms of the extent to which predictive
models encode potential sensorimotor relations (this being “counterfactual richness”).
This is rich and varied territory, and surveying its landmarks emphasizes
the need for experimental tests of its key contributions.
....
I first identify an unusual starting point for PP, not in Helmholtzian perception-as-inference, but in the mid 20th-century cybernetic
theories associated with W. Ross Ashby (1952, 1956; Conant & Ashby 1970). Linking these origins to their modern expression in Karl Friston’s “free energy principle” (2010), perception emerges as a consequence of a more fundamental
imperative towards homeostasis and control, and not as a process designed to furnish a detailed inner “world model” suitable for cognition
and action planning. The ensuing view of PP, while still fluently accounting for (exteroceptive) perception, turns out to be more naturally
applicable to the predictive perception of internal bodily states, instantiating a process of interoceptive inference (Seth 2013; Seth et al.
2011). This concept provides a natural way of thinking of the neural substrates of emotional and mood experiences, and also describes a
common mechanism by which interoceptive and exteroceptive signals can be integrated to provide a unified experience of body ownership
and conscious selfhood (Blanke & Metzinger 2009; Limanowski & Blankenburg 2013).
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