Being You: A New Science of Consciousness

by Anil Seth

At the very deepest layers of the self, beneath even emotions and moods, there lies a cognitively subterranean, inchoate, difficult-to-describe experience of simply being a living organism.

Here, experiences of selfhood emerge in the unstructured feeling of just ‘being’. This is where we reach the core of the beast machine theory: the proposal that conscious experiences of the world around us, and of ourselves within it, happen with, through, and because of our living bodies.

The primary goal for any organism is to continue staying alive. This is true almost by definition – an imperative endowed by evolution. All living organisms strive to maintain their physiological integrity in the

face of danger and opportunity.

Evolutionarily speaking, brains are not ‘for’ rational thinking, linguistic communication, or even for perceiving the world. The most fundamental reason any organism has a brain – or any kind of nervous system – is to help it stay alive, through making sure that its physiological essential variables remain within the tight ranges compatible with its continued survival.

These essential variables, whose effective regulation determines the life-status and future prospects of an organism, are the causes of interoceptive signals. Like all physical properties, these causes remain hidden behind a sensory veil. Just as with the outside world, the brain has no direct access to physiological states of the body, and so these states have to be

inferred through Bayesian bes...

Whereas perceptual inference about the world is often geared towards finding out things, interoceptive inference is primarily about controlling things – it is about physiological regulation.

Interoceptive inference exemplifies active inference, in that prediction errors are minimised by acting to fulfil top-down predictions, rather than by updating the predictions themselves (though this happens too).

These regulatory actions can be external, like reaching for food, or internal, like gastric reflexe...

blood pre...

This kind of predictive control can support anticipatory responses, through predictions about future bodily states and their dependence on this-or-that action. This kind of anticipatory control can be critical for survival. For example, it may turn out very badly to wait for something like blood acidity to go out of bounds before mustering an appropriate response. Again, the relevant actions can be external, internal, or both. Running away from a bear before being eaten is an example of external anticipatory regulation. The transient increase in blood pressur...

Allostasis means the process of achieving stability through change, as compared to the more

familiar term homeostasis, which simply means a tendency towards a state of equilibrium.

We can think of interoceptive inference as being about the allostatic regulation of the physiolo...

Just as predictions about visual sensory signals underpin visual experiences, interoceptive predictions – whether about the future, or about the he...

Despite being firmly rooted in physiological regulation, emotions and moods are still mostly experienced at least in part as relating to things and situations beyond the self, outside the body. When I feel fear, I am usually

afraid of some thing. But the very deepest levels of experienced selfhood – the inchoate feeling of ‘just being’ – seem to lack these external referents altogether. This, for me, is the true ground-state of conscious selfhood: a formless, shapeless, control-oriented perceptual prediction about the present and future physiological condition of the body itself. This is where being you begins, and it is here that we find the most profound connections between life and mind, between our beast machine nature and our conscious self.

The final, and crucial, step in the beast machine theory is to recognise that from this starting point, everything else follows. We are not the beast machines of Descartes, for whom life was irrelevant to mind. It is exactly the opposite. All of our perceptions and experiences, whether of the self or of the world, all are insid...

predictive machinery that evolved, develops, and operates from moment to moment always in light of a fundamental biological drive to stay alive. We are con...

given that ‘change’ is itself an aspect of perceptual inference, the brain may attenuate prior expectations related to perceiving changes in the condition of the body, in order to further ensure that physiological essential variables stay where they ought to be. This implies a form of ‘self-change-blindness’

we perceive ourselves as stable over time in part because of a self-fulfilling prior expectation that our physiological condition is restricted to a particular range, and in part because of a self-fulfilling prior expectation that this condition does not change. In other words, effective physiological regulation may depend on systematically misperceiving the body’s internal state as being more stable than it really is, and as changing less than it really does.

Intriguingly, this proposal may generalise to other, higher levels of selfhood beyond the ground-state of continued physiological integrity. We will be better able to maintain our physiological and psychological identity, at every level of selfhood, if we do not (expect to) perceive ourselves as continually changing.

Across every aspect of being a self, we perceive ourselves as stable over time because we perceive ourselves in order to control ours...

Complementing this subjective stability, most of us most of the time also perceive ourselves as being ‘real’. This may seem obvious, but remember from chapter 6 that the experience of things in the world as ‘really existing’ is not evidence of direct perceptual access to an objective reality, but a phenomenological property that needs to be explained. There, I proposed that to be useful for the perceiving organism, our perceptual best guesses need to be experienced as really existing out there in the world, rather than as the brain-based constructions that in truth ...

passed since I started writing this sentence, the predictive machinery of perception when directed inwardly makes it seem as though there really is a stable essence of ‘me’ at the centre of everything. And in the same way that our perceptions of the world can sometimes lack the phenomenology of being real, the self too can lose its reality. The experienced reality (and subjective stability) of the self may wax and wane during...

Thinking about the material basis of consciousness brings us back, once again, to the hard problem. The beast machine theory accelerates the dissolution of this apparent mystery. By extending the controlled hallucination view to the very deepest layers of selfhood, by revealing the experience of the-self-as-really-existing as one more aspect of perceptual inference, the intuitions on which the hard problem implicitly rest are eroded even further. In particular, the hard-problem-friendly intuition that the conscious self is somehow apart from the rest of nature – a really-existing immaterial inner observer looking out onto a material external world – turns out to be just one more confusion between how things seem and how they are.

Centuries ago, when Descartes and La Mettrie were forming their views about the relations between life and mind, it was not the hard problem that was at issue, but the

existence – or non-existence – of the ‘soul’. And – perhaps surprisingly – there are echoes of the soul to be found in the beast machine story too. This soul is not an immaterial quiddity, nor a spiritual distillation of rationality. The beast machine view of selfhood, with its intimate ties to the body, to the persistent rhythms of the living, returns us to a place liberated from conceits of a computational mind, before Cartesian divisions of mind and matter, reason and non-reason. What we might call the ‘soul’ in this view is the perceptual expression of a deep continuity between mind and life. It is the experience we have when we encounter the deepest levels of embodied selfhood – these inchoate feelings of ‘just being’ – as really existing. It seems right to ...

breath than as thought. We are not cognitive computers, we ar...

Lisa Feldman Barrett, like me, emphasises the role of interoceptive predictions in emotion

her excellent book How Emotions Are Made (Barrett, 2017).

Jean-Pierre Dupuy’s On the Origins of Cognitive Science: The Mechanization of the Mind (2009).

human core body temperature must remain between 32ºC (89.6ºF) and 40ºC (104ºF), otherwise death

rapidly follows.

Metzinger’s concept of ‘existence bias’

A close association between consciousness and physiological regulation raises new questions about the role of the brainstem – the set of nuclei lying between the deepest parts of the cerebral hemispheres and the spinal cord. Typically, the brainstem has been thought of as an ‘enabling factor’ for consciousness, much like a power cable is an enabling factor for a TV. But the brainstem plays a highly active role in physiological regulation, leading some to suggest that this is where consciousness arises – with no need for cortex

think this is extremely unlikely, given the weight of explanatory evidence linking cortex (and thalamus) to conscious states. Having said

this, the brainstem may well play a more decisive role in shaping conscious states than suggested...

is interesting to consider whether self-change-blindness is attenuated during illness or injury, when it might be useful for the brain to more accurately perceive what’s going on in the body. There is a new subfield of cognitive neuroscience which deals with questions like this, called ‘computational psychosomatics’

The Greeks had this down already. While Socrates is associated with the phrase ‘know thyself’, the Stoics emphasised the importance of equanimity and self-control. Advocates of perceptual control theory might go further still, to say that we regulate our physiological condition in order to perceive ourselves as stable.

In September 2020, I hiked across the notorious Sharp Edge ridge on the mountain Blencathra, in England’s Lake District. Although no climbing gear is needed, traversing Sharp Edge is never easy. The ridge’s crest is a jagged mess of slippery rock flanked by precipitous slopes, and accidents do happen. On this particular crossing I noticed an upturned stone at the base of the ridge with the words ‘Marry me, Maria?’ written in chalk. I couldn’t help wonder whether whoever was responsible knew about Dutton and Aron’s experiment, and was taking advantage.

British neuroscientist Karl Friston on his ‘free energy principle’

free energy principle is that it’s a really big idea. It brings together concepts, insights, and methods from biology, physics, statistics, neuroscience, engineering, machine learning, and elsewhere besides. And its application is by no means limited to the brain. For Friston, the free energy

principle explains all features of living systems, from the self-organisation of a single bacterium, to the fine details of brains and nervous systems, to the overall shape and body plan of animals, reaching even as far as the broad strokes of evolution itself. It’s as close to a ‘theory of everything’ in biology as has yet been proposed. It is no wonder that people – me included – were bewildered.

am, whatever I think I am. If I wasn’t, why would I think I am?’

What it means for something to exist is that there must be a difference – a boundary – between that thing and everything else. If there were no boundaries there would be no things – there would be nothing.

This boundary must also persist over time, because things that exist maintain their identity over time.

Things like oil drops and rocks undoubtedly exist, because they have an

identity that persists for some period of time – a long time, for rocks. But neither oil drops nor rocks actively maintain their boundaries, they just get dispersed slowly enough for us to notice them as existing while this happens.