Can we get our heads around consciousness?

Michael Hanlon writes: The question of how the brain produces the feeling of subjective experience, the so-called ‘hard problem’, is a conundrum so intractable that one scientist I know refuses even to discuss it at the dinner table. Another, the British psychologist Stuart Sutherland, declared in 1989 that ‘nothing worth reading has been written on it’. For long periods, it is as if science gives up on the subject in disgust. But the hard problem is back in the news, and a growing number of scientists believe that they have consciousness, if not licked, then at least in their sights.

A triple barrage of neuroscientific, computational and evolutionary artillery promises to reduce the hard problem to a pile of rubble. Today’s consciousness jockeys talk of p‑zombies and Global Workspace Theory, mirror neurones, ego tunnels, and attention schemata. They bow before that deus ex machina of brain science, the functional magnetic resonance imaging (fMRI) machine. Their work is frequently very impressive and it explains a lot. All the same, it is reasonable to doubt whether it can ever hope to land a blow on the hard problem.

For example, fMRI scanners have shown how people’s brains ‘light up’ when they read certain words or see certain pictures. Scientists in California and elsewhere have used clever algorithms to interpret these brain patterns and recover information about the original stimulus — even to the point of being able to reconstruct pictures that the test subject was looking at. This ‘electronic telepathy’ has been hailed as the ultimate death of privacy (which it might be) and as a window on the conscious mind (which it is not).

The problem is that, even if we know what someone is thinking about, or what they are likely to do, we still don’t know what it’s like to be that person. Hemodynamic changes in your prefrontal cortex might tell me that you are looking at a painting of sunflowers, but then, if I thwacked your shin with a hammer, your screams would tell me you were in pain. Neither lets me know what pain or sunflowers feel like for you, or how those feelings come about. In fact, they don’t even tell us whether you really have feelings at all. One can imagine a creature behaving exactly like a human — walking, talking, running away from danger, mating and telling jokes — with absolutely no internal mental life. Such a creature would be, in the philosophical jargon, a zombie. (Zombies, in their various incarnations, feature a great deal in consciousness arguments.)

Why might an animal need to have experiences (‘qualia’, as they are called by some) rather than merely responses? In this magazine, the American psychologist David Barash summarised some of the current theories. One possibility, he says, is that consciousness evolved to let us to overcome the ‘tyranny of pain’. Primitive organisms might be slaves to their immediate wants, but humans have the capacity to reflect on the significance of their sensations, and therefore to make their decisions with a degree of circumspection. This is all very well, except that there is presumably no pain in the non-conscious world to start with, so it is hard to see how the need to avoid it could have propelled consciousness into existence.

Despite such obstacles, the idea is taking root that consciousness isn’t really mysterious at all; complicated, yes, and far from fully understood, but in the end just another biological process that, with a bit more prodding and poking, will soon go the way of DNA, evolution, the circulation of blood, and the biochemistry of photosynthesis. [Continue reading…]

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