NewScientist at 50: Paul Broks on consciousness

Broks gives a whirlwind tour of the last fifty years of neurological research,

a Copernican revolution of the self; a historical shift from the age of solipsism, when we were all at the centre of the universe - self-loving, self-loathing, self-absorbed - to an era of self-dispersion when ego is deemed constrictive. I saw the science of selfhood figure increasingly in the great social and moral debates of the century, from age-old wrangles about euthanasia and free will to disputes over brain enhancement, cyberethics, and the fusion, fission and transposition of minds.

In his most interesting moments, Broks, much like Dr. Oliver Sacks, shows how the brain can break down to reveal its essences.

The neurological diseases that were then still prevalent tended to carve human nature at its joints in such ways, and one occasionally saw what appeared to be clear dissociations of the two "selves". I remember an epileptic patient telling me of her intermittent loss of identity, a condition known as transient epileptic amnesia. Her surroundings would suddenly feel unfamiliar, and then she would begin to feel unfamiliar to herself. Soon she had no idea who she was, where she was or what she was doing. She was stripped to the minimal self: a floating point of subjective awareness untethered by identity.

In other, rare, cases I saw the opposite: the minimal self dissolving, leaving only the story of the extended self. One patient had a strong sense of identity and autobiography but believed that she had ceased to exist. "Am I dead?" she asked. This condition, Cotard's syndrome, was due to a neurological decoupling of feelings and thoughts. Thinking that one exists was not enough: the notion had also to be felt - "I feel I think, therefore I am."

This "dissolution" of the self, in society, in life, in medicine, where does it leave us? Says Brok, "And in the end? A liberating truth. There are no souls, only stories."