The Brain — is wider than the Sky —
For — put them side by side —
The one the other will contain
With ease — and You — beside —

– Emily Dickinson, Complete Poems, 1924

 

It all seems so real. The world around me, filled with colour and noise, alive with objects and the spaces between them. And myself within that world. More than just a body, more than just a perspective, or the point of origin of a willed action. I experience myself as a unified subject of experience in a way that seems just as real as the tree outside my window; as real as the window.

Why is life in the first person? How can the combined activity of nearly ninety-billion brain cells – each one a tiny biological machine – give rise to conscious experiences of the world around us, and of ourselves within it?

Grappling with this mystery, neuroscientists like me look at what happens in the brain when consciousness is lost in sleep or anaesthesia. We map out the neural interactions that shape our perceptions of the external world. But here is the big question. What underlies our sense of self: the experience of being the subject of experience?

One idea is that our conscious experiences of the world, and of being-a-self within it, are ‘controlled hallucinations’, in the memorable words of Ramesh Jain. They are fantasies that sometimes – but not always – coincide with reality.

Because it turns out that the sensory signals delivered to my brain do not disclose an external world in its objective glory. They provide the raw materials my brain uses to generate the rich perceptual scenes that guide our behaviour. We perceive our surroundings – and ourselves within them – not as they are, but as is useful for us to do so. Each of us navigates the buzzing, blooming profusion of our individual worlds by following a probabilistic Ariadne’s thread of self-fulfilling perceptual prophecies.

This hallucination idea is an old one, but its implications are only recently becoming clear. It’s one thing to recognize that our experiences of the world around us are only indirectly related to an external reality. It’s another thing altogether to turn that insight inwards, and to grasp, however tenuously (because the thought, if it is a thought, slips away like water as soon as it appears) that the basic background experience of ‘being me’ is a fragile construction of the brain, another controlled hallucination which can – and sometimes does – disintegrate entirely.

Of course, the immediate experience of being me inevitably and endlessly disrupts any attempt to understand the brain as a mechanism. I am never able to perceive my brain as the basis of my conscious experiences, precisely because it is the basis of all experience. It is the medium, not the message.

But there have been a few occasions in my life when I’ve glimpsed, fleetingly, something from behind that veil, and the dependence of consciousness on the brain has become a part of my lived reality.

In 2007, returning to Brighton after more than six years in California, I suffered major depression. Nothing of academic neuroscience and psychiatry prepared me for it. There were no hallucinated monsters, no voices in the head, but I was dimly able to comprehend that my brain was misperceiving, and therefore also mis-controlling, the interior of its own body – my body. Some of the more elusive symptoms – the overwhelming feelings of bodily discomfort – now began to make sense in terms of these deeply embodied neural interactions. And this was becoming apparent both objectively and subjectively: the medium was becoming the message.

Like many sufferers of depression my main desire at these times was not for greater understanding, but for the absence of all experience. Appropriately enough, the second lifting of the veil happened when I ceased to exist.

I was having a small operation and my brain was filling with anaesthetic. I remember encroaching sensations of blackness, detachment and falling apart and then . . . I was back. Drowsy and disoriented but definitely there. On waking from a deep sleep there’s always a basic sense of time having passed, of a continuity between then and now. Emerging from general anaesthesia is completely different. I could have been under for five minutes, five hours, or five years. I just wasn’t there; I wasn’t anywhere. I was not.

In the language of brain activity, deep general anaesthesia has more in common with catastrophic conditions like the vegetative or minimally conscious states than it does with sleep – something anaestheologists sensibly avoid telling their subjects. With skill it’s even possible to take people down to a level where their electrical brain signals more-or-less flatline, something otherwise only seen in a coma or when near brain death, and then to bring them back safely.

I’ve no idea whether my own anaesthesia reached these depths, most likely it didn’t, but it was enough to plunge me into oblivion, into non-existence. The controlled hallucination of being me dissolved altogether. But instead of the anguish of depression I found this experience – the temporary absence of all experience – deeply reassuring. Oblivion really does mean oblivion.

Life in the first person is both magical and terrifying. But it is circumscribed. And echoing Julian Barnes, when the end comes there is nothing – really nothing – to be afraid of.

 

Image © Carlos Lorenzo

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