Michio Kaku, The Future of the Mind: The scientific quest to understand, enhance and empower the mind 358pp. Allen Lane. £20.00.
No matter what astronomers predict about Halley’s comet, or whether the rest of us believe them, the comet will carry on regardless. But if enough people think that a bank will fail, then, even if the bank is perfectly sound, it will eventually fail, as loss of faith spirals into mass withdrawal of funds. When the sociologist Robert Merton introduced the phrase “self-fulfilling prophecy” in 1948, he used these examples to illustrate what he considered a fundamental difference between predictions about nature and predictions about society. Where the former are either true or false, the latter can become true – and so be “self-fulfilling” – thanks to actions taken under the predictions’ influence.
Most of the futurology in the physicist Michio Kaku’s The Future of the Mind concerns a domain messily intermediate between Merton’s poles of the natural and the social: technology. Part of the fun for Kaku lies in seeing how far, and far out, he can go in envisaging technologies that, though well in advance of existing ones, would violate no known laws of nature. Yet the predictions that result are more like bank-failure predictions than comet-return predictions, in that Kaku might turn out to be correct less because he got the future right than because he helped to shape it, by inspiring readers who went on to become scientists and engineers devoted to transforming his visions into realities.
Certainly Kaku has a better shot than most at reaching such an audience. Over recent decades, he has emerged as a one-man popular-science industry. In the United States especially, he is known as the genial host of radio and television programmes on all sorts of science, as well as the author of engaging articles and books on theoretical physics (his specialism is string theory) and the technoscientific future. The Future of the Mind has benefited twice over from this unusual level of media success. Although Kaku is an outsider to most of the research he explains and extrapolates from, his programme-making got him inside a lot of the laboratories where it takes place. His accounts of what he saw and learned on these visits, not least from the researchers he interviewed, enliven the proceedings throughout. And since the book’s publication, Kaku has been promoting it on American chat shows, helping to propel it up the bestseller lists. If anyone is in a position to influence future technologists of the mind, it is Kaku.
What does he foresee? Above all he stresses continuing improvement in the power of magnetic resonance imaging (MRI) machines and a range of other techniques and technologies used to correlate brain activity and mental activity. Anyone inclined to dismiss brain-scan neuroscience as a new phrenology may be surprised by how much has been achieved and by how hospitable it is to the notion that different people’s brains work differently. Provided that, for a given individual, particular thoughts – visualizing the letter “a”, say, or wagging the left pinkie – reliably go along with particular patterns of neuron firing, as detected by a sensor, it becomes possible to compile an inventory of correlated thoughts and patterns. Once such an inventory becomes large enough, remarkable things can happen. People who have lost the ability to speak or write can type with their minds. People who have lost the ability to control their limbs can move prosthetic ones, just by thinking. Electrode-mediated connections fill in for downed neural connections.
So much is taking place right now. Kaku summarizes and then speculates. If a sensor can deliver our thoughts to a screen, so that they can be conveyed to another person, then it should be possible eventually, he reckons, to cut out the screen from the process, and beam thoughts directly into the ears or even minds of others. He guesses that, given the American military’s track record in funding this kind of project in the past, this future could well take the form of an MRI telepathy helmet capable of functioning under battle conditions:
Here is how it may work in the coming decades. Inside the helmet, there would be electromagnetic coils to produce a weak magnetic field and radio pulses that probe the brain. The raw MRI signals would then be sent to a pocket-size computer placed in your belt. The information would then be radioed to a server located far from the battlefield. The final processing of the data would be done in a supercomputer in a distant city. Then the message would be radioed back to your troops on the battlefield. The troops would hear the message either in a microphone or through electrodes placed in the auditory cortex of their brains.
Further in the future still, and rather more benignly, Kaku sees telepathy as taking place via carbon “nanoprobes” implanted in our brains, maybe even at birth, so that telepathy would become just another taken-for-granted human skill. Kaku’s inspiration for that last scenario is, he tells us, an episode of Star Trek. A great deal of his future for the mind appears to have been scripted in Hollywood. The neuro-prostheses of today will, he expects, be ancestral to powerful mind-controlled exoskeletons and even avatars straight out of Avatar. A chapter explaining how we might one day, à la Inception, enter into each other’s dreams explores a further, fascinating variation on the MRI technology theme. Suppose it is your turn to be the dreamer. You are asleep, dreaming. A sensor on or near your brain transmits neuron-firing data to a computer in whose memory is stored the inventory relating your neuron-firing patterns and the images passing through your mind. (What holds for letters and intended movements holds too, it seems, for images.) I am in a studio, watching your dream on a monitor, or maybe in special contact lenses, thanks to the computer’s use of the inventory to turn your neuron-firing data into images. A video camera trained on me functions to project my image into this dreamscape, and I begin interacting with people and objects there. At the same time, the camera transmits the image of me into special contact lenses that you are wearing. From there the image gets projected onto your retina, stimulating your optic nerve, which sends an impulse to your visual cortex, which your mind registers as me in your dream.
Other chapters deal in similar style with the prospects for human memory, intelligence, mind control and mental illness, and the implications in these and other areas of the huge brain-mapping and brain-simulation projects recently launched in the US and Europe, as well as likely advances in gene, drug, magnetic and electrical therapies. There are brief discussions throughout of ethical challenges ahead, none of which Kaku finds very troubling. Of greater interest to him is what he calls his “space-time theory of consciousness”, set out in an early chapter and referred to periodically thereafter. The Einsteinian ring of “space-time” is misleading, as Kaku means to suggest merely that, considered as an inner model of the world, consciousness increases in power with the kinds and number of relations represented, spatial and temporal relations but also – another reason the name is inapt – social ones. He makes such heavy weather of the theory that one expects to find that, by some technological means or other to be revealed later in the book, our descendants will enjoy a relation-enriched super-consciousness whose glories we can scarcely imagine. But no such luck for the reader or, it seems, for humankind. Indeed, nothing of what Kaku predicts for the mind’s techno-future depends on his space-time theory, much less on an analogy he fitfully favours between the mind and a large corporation, complete with a dynamic CEO, whom he locates in the prefrontal cortex.
This is Kaku’s version of old-fashioned homunculus talk. He can also fail to argue his point. Some way into a chapter on artificial intelligence, for example, full of absorbing reportage and reflections on everything from how robots look (too humanlike, apparently, makes people uncomfortable) to whether robots might take over one day (yes, probably, but, in the view of Kaku’s interviewees, it should make us proud to bequeath our world to such go-getter children), he raises the question of whether a non-biological machine can be conscious. Over two-and-a-half pages he oscillates between insisting that the question should be dropped because unanswerable, since terms such as “feel” and “understand” are not well defined, and insisting that, if a non-biological machine one day passes the Turing test – by holding up its side of a conversation at least as well as a human interlocutor would – then the machine would count as conscious.
There is, to put it mildly, room for resistance here. So what if “feel” and “understand” are imprecisely defined? Welcome to language, scientific language (yes, even in physics) very much included. And is the Turing test actually a good test of consciousness? Kaku presumes so, as do many commentators on both sides of the recent controversy over whether the snarky-teen chatbot Eugene Goostman has passed the test. But as John Searle pointed out years ago, when we impute understanding to our fellow humans, it is not just on the basis of their capacity to furnish appropriate responses in conversation. There is also the fact that they are built the way we are, right up to the prefrontal cortex. We know, from the inside, that beings with brains likes ours are conscious. As for things not remotely built like us – Eugene Goostman, say, robots guided by hugely powerful silicon-chip computers – well, maybe they are conscious, or maybe they can at best only simulate being conscious. A winning performance on the Turing test is compatible with both possibilities.
Let us, charitably, allow that an inspired reader of The Future of the Mind solves this problem one day, and it becomes possible to tell whether or not a non-biological machine is conscious. Following the lead of others, Kaku outlines the technological means by which humans might transfer their consciousness onto computers and so, potentially, become immortal. Furthermore, once human consciousness has gone digital, it can, as Kaku sees it, go anywhere, travelling on laser beams all over the universe, indeed slipping through wormholes to parallel universes. Maybe encountering aliens along the way (their minds get a chapter too). It would certainly exercise free will of a kind, courtesy of gaps in determinism due to chaos and quantum effects (surveyed in an appendix on “quantum consciousness”).
And all the while, what we call Halley’s comet carries on regardless. It will return to Earth’s vicinity, our astronomers predict, in summer 2061. Futurology of that sturdily dependable but still deeply impressive sort can come as a relief after Kaku’s book, with its mixture of second-hand science and second-hand science fiction, and its relentless optimism about new technology and our power to avoid any of its downsides. Bu just think how pleased you will be, as you settle in to watch the comet, with your artificial hippocampus working to store memories of the scene (one among many prostheses helping you combat time’s ravages), and your freshly uploaded knowledge of up-to-date cosmology aiding your appreciation of the spectacle, to know that you saw it all coming.
Gregory Radick is Professor of History and Philosophy of Science at the University of Leeds and the author of The Simian Tongue: The Long Debate about Animal Language, 2007. He is working on a new history of the birth of genetics.