Being You: A New Science of Consciousness

by Anil Seth

Indeed, the experience of being a unified self can come undone all too easily. The sense of personal identity, built on the narrative self, can erode or disappear entirely in dementia and in severe cases of amnesia, and it can be warped and distorted in cases of delirium, whether hospital-induced or not. The volitional self can go awry in conditions like schizophrenia and alien hand syndrome, when people experience a reduced sense of connection with their own actions, or in akinetic mutism, a disorder in which people stop interacting with their surroundings altogether. Out-of-body experiences and other dissociative disorders affect the perspectival self, while disorders of body ownership range from phantom limb syndrome – the experience

of persistent, often painful sensations located in a limb that is no longer there – to somatoparaphrenia – the experience that one of your limbs belongs to someone else. In xenomelia – an extreme form of somatoparaphrenia – people experience an intense desire to amputate an arm or a leg, a drastic remedy which on rare occasions they actually carry out.

The self is not an immutable entity that lurks behind the windows of the eyes, looking out into the world and controlling the body as a pilot controls a plane. The experience of being me, or of being you, is a perception itself – or better, a collection of perceptions – a tightly woven bundle of neurally encoded predictions geared towa...

In 2007 two papers appeared in the prestigious journal Science at almost the same time. Both described how new methods in virtual reality could be used to generate an ‘out-of-body-like’ experience. The experiments were based on the rubber hand illusion, but now extended to the entire body. In one of the studies, conducted by a group in Lausanne led by Olaf Blanke, volunteers wore a head-mounted display through which they saw a virtual reality representation of the back of

their own body from a distance of about two metres (see opposite). From this perspective, they then saw the virtual body being stroked with a paintbrush, again either synchronously or asynchronously with strokes applied to their own (real) body. When the stroking was synchronous, most participants reported that they felt the virtual body was, to some extent, their ‘own’ body, and when asked to walk to where they felt their body was, they showed a drift in space towards the location of the virtual body. In the same way that the rubber hand illusion hints at a moment-to-moment flexibility of body ownership, experiments like this – which are called ‘full body illusions’ – suggest that the subjective ownership of the entire body, and the location of the first-person perspective, can also be manipulated on the fly. These experiments provide fascinating evidence that experiences of ‘what is my body’

can be dissociated, at least to some extent, from experiences of ‘where I am’. Fig. 18: Creat...

The idea that one’s first-person perspective can leave the physical body in the form of out-of-body experiences – OBEs – is deepl...

Reports of OBEs or OBE-like experiences during traumatic near-death experiences, in operating theatres, and in the periphery of epileptic seizures have fuell...

Among Penfield’s patients was a woman known as G.A. who, when electrically stimulated in her right superior temporal gyrus – part of the brain’s temporal lobe – spontaneously exclaimed, ‘I have a queer sensation that I am not here … As though I were half here and half not here.’ Blanke himself first became fascinated by OBEs when

patient of his, stimulated in a similar part of the brain – the angular gyrus, at the junction of the temporal and parietal lobes – reported a similar experience: ‘I see myself lying in bed, from above, but I only see my legs.’ The common factor in cases like these is unusual activity in brain regions that deal with vestibular input (the vestibular system deals with the sense of balance) and that are also involved in multisensory integration. It seems that when normal activity in these systems becomes disrupted, the brain can reach an unusual ‘best guess’ about the location of its first-person perspective, even while other aspects of selfhood are left unaltered.

The OBE-like experiences that sometimes accompany epileptic seizures can also be traced to disruptions in these processes. These experiences are usually divided into autoscopic hallucinations – in which y...

and heautoscopic hallucinations (also known as doppelgänger hallucinations) – in which you see yourself...

People have had real out-of-body experiences for millennia, but this does not mean that immaterial selves or immutable souls have ever actually left any physical bodies. What these reports reveal is that first-person perspectives are put together in more complex, provisional, and precarious ways than we will ever have direct subjective access to.

In the virtual world, the ability to alter first-person perspectives is generating some fascinating applications, many of them driven by the intriguingly named ‘body swap’ illusion, which was described in a 2008 study led by the Swedish researcher Henrik Ehrsson. In the body swap set-up, two people wear head-mounted displays, each with a camera attached. By swapping the camera feeds between the headsets, each person can see themselves from the other’s point of view. The effect kicks in properly only when they shake hands. The idea is that seeing and simultaneously feeling the handshake provides the multisensory stimulation so that, when combined with top-down expectations, each person feels they are now somehow located in the other person’s body, shaking hands with themselves.

His inability to string together a self-narrative over time means that what-it-is-to-be-him has been, for more than thirty years, a continual starting from scratch, a fleeting presence with no stable ‘I’ around which to organise the flow of perceptions of world and self.

Generative models, as we know, are able to generate the sensory signals

corresponding to a particular perceptual hypothesis. For social perception, this means a hypothesis about another’s mental states. This implies a high degree of reciprocity. My best model of your mental states will include a model of how you model my mental states. In other words, I can only understand what’s in your mind if I try to understand how you are perceiving the contents of my mind. It is in this way that we perceive ourselves refracted through the minds of others. This is what the social self is all about, and these socially nested predictive perceptions are an important part of the overall experience of being a human self.

One intriguing implication of this construal of the social self is that self-awareness – the higher reaches of selfhood comprising both narrative and social aspects – might necessarily require a social context. If you exist in a world without any other minds – more specifically, without any other relevant minds – there would

be no need for your brain to predict the mental states of others, and therefore no need for it to infer that its own experiences and actions belong to any self at all. John Donne’s seventeenth-century meditation that ‘no man is an island’ could be literally true.

Compared to perceptual experiences of the outside world, self-related experiences are remarkably stable. Our perceptions of the world are always changing, objects and scenes coming and going in a continual flux of events. Self-related experiences seem to change much less.

This subjective blindness to the changing self has consequences. For one thing, it fosters the false intuition that the self is an immutable entity, rather than a bundle of perceptions.

But this is not the reason that evolution designed our experiences of selfhood this way. I believe that the subjective stability of the self goes beyond even the change blindness warranted by our slowly changing bodies and brains. We live with an exaggerated, extreme form of self-change-blindness, and to understand why, we

need to understand the reason we perceive ourselves in the first place. We do not perceive ourselves in order to know ourselves, we perceive ...

Our conscious experiences of the world around us, and of ourselves within it, happen with, through, and because of our living bodies.

Underneath the layered expressions of selfhood involving memories of the past and plans for the future, before the explicit sense of personal identity, beneath the ‘I’ and even prior to the emergence of a first-person perspective and experiences of body ownership, there are deeper layers of selfhood still to be found. These bedrock layers are intimately tied to the interior of the body, rather than to the body as an object in the world, and they range from emotions and moods – what psychologists call ‘affective’ experiences – to a basal, formless, and ever-present sense of simply ‘being’ an embodied, living organism.

We’ll start our exploration of these depths with emotions and moods. These forms of conscious content are central to the experience of being an embodied self, and – like all

perceptions – they too can be understood as Bayesian best guesses about the causes of sensory signals. The distinctive thing about affective experiences is that the relevant causes are to be found...

Interoceptive signals report things like heartbeats, blood pressure levels, various low-level aspects of blood chemistry, degrees of gastric tension, how breathing is going, and so on. These signals travel through a complex network of nerves and deep-lying brain regions in the brainstem and thalamus before arriving at parts of the cortex specialised for interoceptive processing – in particular the insular

The key property of interoceptive signals is that they reflect, in one way or another, how well physiological regulation of the body is going. In other words, how good a job the brain is doing of keeping its body alive.

emotions are perceptions of changes in bodily state. We don’t cry because we are sad, we are sad because we perceive our bodily state in the condition of crying. The emotion of fear, in this view, is constituted by (interoceptive) perception of a whole gamut of bodily responses set off by the organism recognising danger in its environment. For James, the perception of bodily changes as they occur is the emotion: ‘We feel sorry because we cry, angry because we strike, afraid because we tremble, and not that we cry, strike, or tremble, because we are sorry, angry, or fearful.’

increased physiological arousal, induced by the rickety bridge, had been misinterpreted by higher-level cognitive systems as sexual chemistry.

it still vividly illustrates the view that emotional experiences depend on how physiological changes are evaluated by higher-level cognitive processes.

Emotions and moods, like all perceptions, come from the inside out, not the outside in. Whether it’s fear, anxiety, joy, or regret – every emotional experience is rooted in top-down perceptual best guessing about the

state of the body (and about the causes of this state).

Recognising this is the first key step towards understanding how experiences of being an embodied self are tied to...

Cybernetics – from the Greek kybernetes, meaning ‘steersman’ or ‘governor’ – was described by one of its founders, the mathematician Norbert Wiener, as ‘the scientific study of control and communication in the animal and the machine’.

‘Every good regulator of a system must be a model of that system’.

Let’s take this example a step further. Imagine that System B has been fitted with imperfect ‘noisy’ temperature sensors that only indirectly reflect the ambient temperature in the house. This means that the actual temperature cannot be directly ‘read off’ from the sensors; instead, it has to be inferred on the basis of the sensory data and prior expectations. System B now has to have a

model of (i) how its sensor readings relate to their hidden causes (the actual temperature in the house), and (ii) how these causes will respond to different actions, such as adjusting the boiler or radiator output.

We are now in a position to connect these ideas about regulation to what we know about predictive perception. System B works by inferring the ambient temperature from sensor readings, just as our brain makes best guesses about the causes of its sensory signals in order to infer states of the world (and body) and how they change over time. But the goal for System B is not to figure out ‘what’s there’ – in this case the ambient temperature. The goal is to regulate this inferred hidden cause, to take action so as to keep the temperature within a comfortable...

Control-oriented perception –...

thing implemented by System B – is therefore a form of active inference, the process by which sensory prediction errors are minimised through making actions rather than by updating predictions. As I explained in chapter 5, active inference depends both on generative models which are able to predict how the causes of sensory signals respond to different actions, and on modulating the balance between top-do...

Active inference tells us that predictive perception can be geared either towards inferring features of the world (or the body) or towards regulating these features – it can be about finding out things or about controlling things. What cybernetics brings to the table is the idea that, for some systems, control comes...

predictive perception and active inference emerges from a fundamental requirement about what it takes to...

To answer the question of what perceptions of emotion and mood are for, we need one more concept from cybernetics – that of an essential variable. Also introduced by Ross Ashby, essential variables are physiological quantities, such as body temperature, sugar levels, oxygen levels and the like, that must be kept within certain rather strict limits in order for an organism to remain alive. By analogy, a desired room temperature would be the ‘essential variable’ for a central heating system. Putting these pieces together, emotions and moods can now be understood as control-oriented perceptions which regulate th...

specifically ‘my body in the presence of an approaching bear’ – that sets in train the actions that are best predicted to keep my essential variables where they need to be. Importantly, these actions can be both external movements of the body – like running – and internal ‘...

This perspective on emotions and moods ties them even more closely to our flesh-and-blood nature. These forms of self-perception are not merely about registering the state of the body, whether from the outside or from the inside. They are intimately and causally bound up with how well we are doing, a...

the psychologist James Gibson argued that we often perceive the world in terms of what he called ‘affordances’. An affordance, for Gibson, is an opportunity for action – a door for opening, a ball for catching – rather than an action-independent representation of the ‘way things are’.

The control-oriented perceptions that underpin emotions and moods are all about predicting the consequences of actions for keeping the body’s essential variables where they belong. This is why, instead of experiencing emotions as objects, we experience how well or badly our overall situation is going, and is likely to go.

Whether I’m sitting by my mother’s hospital bed, or fixing to escape from a bear, the form and quality of my emotional experiences are the way they are – desolate, hopeful, panicky, calm – because of the conditional predictions my brain is making about how different actions might impact my current and future physiological condition.