By Charles Foster
I am aware (as my academic critics will agree) of only a tiny proportion of what I do and what I am. It is not clear what sort of creature I am, but what is clear is that very little of me is visible to myself – let alone to others. We are all icebergs.
The bits of which I am aware are, it seems, far less potent than the bits of which I am unaware. The motor driving my actions is buried deep within my unconscious. Sometimes, in dream or drunkenness, I get a glimpse into the engine room, or hear the motor turning. But I have really little idea of what goes on down there, or how it relates to the parts of me that I can see. I can ride my bike more or less unconsciously into town through rush-hour traffic or sit, awake but somewhere else, through a lecture. If you think I’m unusual, consider Susan Blackmore’s startling question: ‘What were you aware of a moment ago?’
If it is true that the unexamined life is not worth living, my life is not worth living. But I rather think it is.
These reflections make me queasy about the way that we approach the withdrawal of life-sustaining treatment from patients in prolonged disorders of consciousness (PDOCs). That treatment will be unlawful unless it is in the best interests of the patient. In determining best interests, clinicians look for evidence of self-awareness: they search for the footprints – the neural correlates – of consciousness. The lenses through which they look cannot, by definition, see anything of the subconscious life. If we are predominantly driven by and defined by our subconscious, that’s a problem. At best, the best interests determination will be based on objectively verifiable evidence of a pretty unimportant commodity – consciousness.
The increasing use of functional imaging technologies in the assessment of PDOC patients is troubling. They lend a wholly spurious aura of scientific validity to the best interests determination. These technologies typically track blood flow to the various areas of the brain. If there’s anything in what I’ve written above, this is a wholly pointless exercise, simply because no one has ever been able to point to a piece of brain tissue and say: ‘That’s the residence of the unconscious’.
But even if it makes sense to determine best interests on the basis only of demonstrable self-awareness, functional imaging is of dubious value. I’ll make the extravagant and generous assumption that certain brain areas, or constellations of brain areas, are reliably associated with self-awareness. If the assumption is right, what is it safe to conclude from the evidence of increased blood flow? Not much. Brains aren’t built from monolithic blocks – each block having a simple and easily identifiable function. Brain areas are hubs for conversation and decision. They fizz with discussion. Sure, some types of conversation are more likely to be heard in one place than another, but they are often influenced by ideas from far outside their habitual forum. There are other confounding factors too. Here’s just one: It’s assumed that increased blood flow means increased activity. This, to a first degree of approximation, is right, but one has to be careful, since much brain activity is inhibitory: Area A is active in order to suppress area B.
Outside the sphere of imaging, the clinical tools available for the assessment of awareness are crude in the extreme.
So: even if you think it is sensible to describe icebergs on the basis of knowledge of their tips, you might think it’s worrying to come to a definitive view when you’ve had only a momentary glance at the tip, through dense fog, when you’ve wearing dark glasses and have drunk a couple of bottles of claret.
Also:
Deal with the real, not the notional patient, and don’t ignore important uncertainties
Author: Charles Foster
Affiliations: Faculty of Law, University of Oxford
Competing interests: None
Social media accounts of post author: @tweedpipe