Conversations on Consciousness

In Ben Libet’s 1985 experiments, subjects had to flex their wrist spontaneously
and deliberately at a time of their own choosing. The time of the movement was
measured using EMG (electromyogram) electrodes on their wrist; the start of the
readiness potential in their motor cortex was measured using EEG (electroencephalogram);
the moment at which they consciously decided to move was measured using
a spot revolving on a screen; they had to say (after the movement) where the spot
was at the moment of willing. The results showed that brain activity began nearly
half a second before the will to move. Libet’s controversial experiments have been
interpreted by some as having implications for free will. Sue


Sue You’re being rather coy about your contribution to consciousness studies.
I know you have a theory about the function of consciousness. Tell
me something about that.
Richard OK, the other big question is what consciousness does. I don’t
think it’s uniquely human. I mean you can stand on a dog’s tail and it
yelps. It feels it. That’s my view anyway. So then you must ask yourself
what the function of it is, on the grounds that it wouldn’t evolve unless
it has a survival function. And what strikes me about consciousness is
that it’s very much associated with the present moment.
When you’re perceiving things, the brain has a vast amount of processing
going on from the past. For example, in order to see that cup
in front of us I have to have picked up cups in the past, poured coffee
into them, probably dropped them and broken them, and done all
sorts of things to them. Then I see that cup as a real object, not just
because I’ve got a retinal image and a bunch of signals going into the
cortex, but because it’s evoking all this from the past. Now it seems
to me that you’ve got to live in the present moment; you’ve got to
survive crossing the road. So it really matters that the traffic light is
red or green now, at this moment in time, whereas the processes of
perceiving are spread out in time. So how do you locate the present
moment? I suggest that this is tagged, or flagged if you like, by consciousness.
You’ve got this extraordinary sense of vividness, of qualia,
which always applies to the present moment.
Sue So are you saying then that the function of consciousness is to discriminate
the past and the future from what’s now, and requires action?
Richard Yes, absolutely.
Richard Gregory