Seth’s “Beast Machine” Theory

Neuroscientist Anil Seth extends top-down predictive theories with his neuroscience-informed “beast machine” theory that conscious experiences can be understood as forms of brain-based perceptual prediction within the general framework of predictive processing accounts of brain perception, cognition, and action.

More specifically, his theory proposes that phenomenological properties of conscious experiences can be explained by computational aspects of different forms of perceptual prediction. A key instance of this is in the ability to account for differences between experiences of the world and experiences of the self.

The theory also proposes that the predictive machinery underlying consciousness arose via a fundamental biological imperative to regulate bodily physiology, namely, to stay alive. We experience the world around us, and ourselves within it, with, through, and because of our living bodies (Seth, 2021a, 2021b).

Controlled Hallucinations and Conscious Perception

Seth says that our conscious experiences of the world and the self are forms of brain-based prediction—which he labels “controlled hallucinations.”^[1] He asks, how does the brain transform what are inherently ambiguous, electrical sensory signals into a coherent perceptual world full of objects, people, and places?

The key idea is that the brain is a “prediction machine,” and that what we see, hear, and feel is nothing more than the brain's “best guess” of the causes of its sensory inputs. Because perceptual experience is determined by the content of the (top-down) predictions, and not by the (bottom-up) sensory signals, we never experience sensory signals themselves, we only ever experience interpretations of them.

Thus, “what we actually perceive is a top-down, inside-out neuronal fantasy that is reined in by reality, not a transparent window onto whatever that reality may be.” Taking this idea seriously and seeking its implications, Seth proposes that the contents of consciousness are a kind of waking dream—the “controlled hallucination”—that is both more than and less than whatever the real world really is.

He offers slyly the insight that “you could even say that we're all hallucinating all the time. It's just that when we agree about our hallucinations, that's what we call reality” (Seth, 2021a, 2021b).

Footnote

[1]. Seth first heard the phrase “controlled hallucination” from British psychologist Chris Frith and traced it back to a seminar given in the 1990s by Ramesh Jain (Seth, 2021a).