categorising, reacting to faces, and processing numbers. In one study, a monitored neuron consistently fired only when its owner viewed images of Jennifer Aniston! Consciousness, thinks Dehaene, may have evolved to pick out what is relevant from this huge amount of parallel activity, and keep it active within the global workspace while different parts of the brain evaluate it. It is necessary so we can deal with one important thing at a time and enable a kind of “collective intelligence” to be reached. That would include providing access to memory and mental associations, as well as to language processors which could describe the ongoing experience, Dehaene suggests. It all takes time, which may explain why consciousness seems to run about a third of a second behind reality. Could the rich experience of consciousness, which feels as though it brings together sensation, interpretation, memories and language, really be no more than this “global sharing of information”? The metaphor is certainly attractive but some will disagree. For these critics, the mental “feel” of the colour red, say, won’t be found by adding up the firing of brain cells which detect red, the association of red in your memory, and the labelling of the colour with a word. How the firing of cells can “feel” like something is the philosophical “hard problem” of consciousness. And it’s a problem researchers think needs wholly new kinds of answers. Kaku has a view on the hard problem, too. But before getting there, he explores everything he can think of on the future of the mind. When he was small, Kaku recalls: “I used to love taking apart clocks.” From his delightfully odd book, I suspect it would still be unwise to leave him alone in your home with a screwdriver, for his curiosity is endless.
He’s looking for machines that can read minds, and when he encounters the first efforts (in none other than Dehaene’s lab) he wonders whether one day we might have to devise shields to block our most private thoughts. At one stage he meets the visionary scientist Miguel Nicolelis, who has made remarkable progress at Duke University, North Carolina, in getting the brain to directly control a wearable exoskeleton designed to help disabled people
Robots will be able to process a sensation, such as seeing the colour red, better than any human
walk. The two men seem to be kindred spirits. In their conversations we are flung into the future beyond mere mind melds to a “brain net” – an “internet of the brain” which transmits thoughts, emotions and ideas in real time between brains. Kaku is enthusiastic, but not naive, and he has a knack of asking the most disarming questions and using his physicist’s sharp brain to see flaws in much-touted ideas. For example, when he meets the creators of ASIMO, a robot made by Honda that can run, dance and apparently speak different languages, and asks how smart it is, the answer is that the robot is still at a primitive level, requiring lots of clever programmers to script its complex movements. Finally, Kaku has his own take on the hard problem of phenomenal experience. In the future, he speculates, robots will be able to process a sensation, such as seeing the colour red, better than any human and even use it, poetically, in a sentence. At that point, writes Kaku, robots will rightly comment: “Perhaps humans cannot really understand the colour red with all the nuances and subtlety that a robot can.” ■
Aucun commentaire:
Enregistrer un commentaire