life, death and consciousness

I finished reading this fascinating book, and would like to share a few segments with you. The entire book is useful for anyone considering the right to life of a fetus or the right to life (or death) of an unconscious, older person in a vegetative state. It has made me re-think my ‘living will’, my request that no special efforts be made to prolong my life should I become unconscious and unresponsive.

What is consciousness? This is a surprisingly complex question. The author of this book, British neuroscientist Adrian Owen, explains that “part of the problem is that questions about consciousness have as much to do with personal taste as science”.

Take the example of a young child. Most of us would agree that healthy ten-year-old children are conscious of themselves and the world around them in much the same way that adults are. ….

What about two-year-olds? Are they conscious? Most of us would say yes. ….

Now consider a one-month old. Of course a one-month-old is conscious, you say! But think about it. One-month-old infants don’t seem to understand what is said to them, although it might be possible to attract their attention momentarily with an “Ooh” or “Aah.” If you scream at them (you shouldn’t), they might start to cry; if you sing softly, they grow calm and perhaps coo. But that’s about it.

…. [Infants] may or may not be laying down memories (few of us claim to remember being one month old), and they clearly don’t appear to act based on remembered information in the way that a two-year-old will. ….

In short, it’s a lot more difficult to decide whether one-month-olds are or are not conscious, and unsurprisingly, we are divided: some of us think they are; others aren’t so sure. ….

…. What about a fetus? Is it conscious? …. Let’s push back further. What about a zygote–the single cell formed from the sperm and the egg that leads, nine months later, to the birth of a child? Is a zygote conscious? Most people will agree it isn’t ….

This raises an interesting problem. When, then, on this developmental trajectory from zygote to fetus to newborn to toddler to adult, does consciousness emerge? …. If you agree that a single-celled zygote is unlikely to be conscious, but a healthy adult is, then somewhere between these two points we must become conscious. But when? Birth is an obvious and dramatic change point, but it seems highly unlikely that a child fresh from the womb is any more conscious than a nine-month-old fetus about to be born.

….

What we do know is that the fetal brain does not even begin to develop until three to four weeks after conception …. The major divisions of the adult brain emerge at four to eight weeks into pregnancy, but only after about eight weeks does the cerebral cortex separate into two distinct hemispheres. At twelve weeks, rudimentary neuronal connections are emerging …, but these are not sufficient to support conscious experience.

Moving to adults with severe brain injuries or diseases, some appear to be only minimally conscious.

It’s often unclear what the term means–it’s hard enough to get scientists to agree on what consciousness is, let alone define what minimal consciousness means. But let’s just say that being minimally conscious means that sometimes you’re there, sometimes not, and sometimes you’re stuck in between. Either way, at best you can give some subtle signal–perhaps the movement of a finger–to say you’re there. At worst, you can’t even do that. ….

…. [Yet we encountered] four patients who appeared to be vegetative, yet … were not vegetative at all. They were in a state–a part of the gray zone–for which we still have no name. And in that part of the gray zone, you can be completely awake, completely aware, yet completely physically nonresponsive–unable to blink an eye, raise an eyebrow, or move a muscle.

[…]

Any sort of brain injury will likely have long-lasting pervasive effects. It’s not the same for any other organ of the body. We can replace kidneys, lungs, hearts and livers and essentially we are still ourselves ….

But serious brain injury is fundamentally different. It changes us, it alters our ability to move, react, interact, and respond. And recovery is far harder, if it occurs at all. We can’t transplant brains (at least not yet), but even if we could, … “we” would not recover; “we” would be someone else. We might look the same, but with someone else’s brain in our heads we would be an entirely different person. ….

There’s no escaping it: we are our brains.

Adrian Owen, Into the Gray Zone (Scribner, 2017), pp. 64-67, 122-123, 224-225.

Adrian M. Owen (born 1966) is best known for publishing in 2006 a scientific paper showing that some patients, thought to be in a vegetative state, are in fact fully aware and able to communicate with the outside world using techniques such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG).

Owen completed a PhD in Psychiatry at King’s College London in 1992, then moved to the Cognitive Neuroscience Unit at the Montreal Neurological Institute, McGill University. He returned to the UK in 1997 to pursue research in cognitive neuroscience at Cambridge University. In 2011 he returned to Canada with most of his research team, attracted by a $10m federal research grant for use at the University of Western Ontario. He does not have an MD, and is a researcher, not a physician.

Tags:

Comments are closed.