[[Published in The Times Literary Supplement, October 1994.]]
How does conscious experience emerge from a physical basis? At a first glance, this is the question about the mind that most needs answering. So it is curious that those who study the mind professionally have often avoided the question entirely. In psychology, the cognitive revolution did not make consciousness respectable: most cognitive psychologists have stuck to subjects such as learning, memory, and perception instead. Neuroscientists have been known to speculate on the topic, but usually only late at night, after a few drinks. Even philosophers have been curiously diffident. Some have been exercised by the fact that there is a problem, others have been concerned to deny the problem entirely, but the focus of inquiry has remained elsewhere. As in all these fields, serious theories of consciousness have been hard to come by.
But consciousness is making a comeback. In the last few years, popular books on the subject by Francis Crick, Daniel Dennett, and Roger Penrose have provoked widespread discussion. Not everybody agrees on just what the problems are, and almost nobody agrees on where a solution will lie, but almost everyone has an opinion. Philosophers are having a field day, neuroscientists are speculating a little earlier in the evening, and even psychologists have begun to sheepishly utter the dreaded C-word. At conferences on the subject, researchers from different fields are learning to speak each other's language. New books are appearing every month. And there are now three academic journals devoted to the subject.
The latest and flashiest of these journals is the Journal of Consciousness Studies. The first issue boasts interviews with such luminaries as Crick and Penrose, a number of conference reports, and refereed articles on consciousness based in areas as diverse as quantum mechanics and Buddhist philosophy. The journal's center of gravity is outside the mainstream, with the editors admitting a preference for "radical" conceptualizations of the subject. The bulk of the first issue is devoted to scientific approaches of one sort or another, but we are promised a discussion of "ethical, spiritual, and social issues" in the future. All in all, the journal is surprisingly accessible to the general reader, and despite its biases it provides a useful look at the state of play in consciousness research circa 1994.
One thing that quickly becomes clear is that the most puzzling questions about consciousness are just as puzzling as ever. A distinction is made a number of times between the "easy" problems of consciousness and the "hard" problem. The easy problems are those of finding neural mechanisms and explaining cognitive functions: the ability to discriminate and categorize environmental stimuli, the capacity to verbally report mental states, the difference between waking and sleeping. The hard problem is that of experience: why does all this processing give rise to an experienced inner life at all? While progress is being made on the easy problems, the hard problem remains perplexing. Even Crick and Penrose concede that so far they have little idea how the problem might be solved. They simply hope that if we do enough investigation in neuroscience (for Crick) or in physics (for Penrose), the faint outlines of a solution might be revealed. At this point, such remarks are not much more than an expression of faith.
But even without a solution to the hard problem, there is much of interest in the field of consciousness studies. The papers in this issue range from the conventional to the exotic. The most sober paper concerns the "binding problem" in neuroscience - the problem of how the brain integrates different pieces of information about the same object. A popular hypothesis has been that binding is achieved by groups of neurons oscillating in phase, but philosopher Valerie Hardcastle suggests that the evidence here is weak, and recommends a higher-level approach to the issue. In tying together evidence from a number of different fields, this thoughtful paper illustrates the benefits of an interdisciplinary approach to the science of the mind.
It is the quantum-mechanical papers that will draw the most attention. In a hypothesis that has been endorsed by Penrose, anesthesiologist Stuart Hameroff suggests that the key to consciousness lies in microtubules, large molecules found within the cell wall of a neuron. Noting that these are finely poised between the quantum and neural realms - small enough to maintain a state of quantum coherence, but large enough to affect neural activity - Hameroff argues that these could mediate a quantum role in brain function. This is recommended as a solution to the binding problem (through quantum nonlocality), as an explanation of "intuitive" processing (through quantum superposition) and problem-solving (through wavefunction collapse), and even as the key to the problem of free will (through quantum indeterminacy)! Critics will respond that all of these problems can be handled by orthodox methods, but Hameroff's ideas are at least provocative.
Another paper presents experimental evidence that EEG measurements on the brain affect performance on various cognitive tasks. The authors (Nunn, Clarke, and Blott) suggest that the measurement may cause the brain's quantum wave state to collapse! Perhaps this is related to Benjamin Libet's suggestion in a neighbouring paper that the brain has an associated "conscious mental field", which may affect neural function. In both cases, however, the evidence is quite tenuous, and one might ask for a more rigorous theoretical basis for the strong claims that are made. On the other hand, psychologist John Beloff provides a spirited defense of the claims of parapsychology, and argues that the experimental evidence has been dismissed more quickly than it should have been. There is room for a debate here: just when do well-supported prior convictions justify the easy dismissal of evidence for radically different views? No doubt many mainstream scientists will dismiss the evidence of Nunn et al and of Beloff without qualms. Is this reasonable?
Two of the most interesting papers relate Eastern thought to the study of the mind. Eleanor Rosch uses some ideas from the Buddhist Madhyamika school in developing a theory of the way that people think about causality, and Robert Forman discusses mystical experiences as revealed in the writings of the Hindu Upanishads. Rosch brings the Buddhist ideas to bear on issues in cognitive psychology, while Forman uses his study to help adjudicate a debate between "constructivists" and "decontextualists" in religious studies. In papers like these, there is no claim that a theory of consciousness is on offer, but the wide-ranging discussion provides useful insights.
To judge from this issue, one would think that researchers on consciousness come in four varieties: neuroscientists, quantum theorists, parapsychologists, and mystics. This makes for a spicy journal, but it would be nice to see contributions from mainstream cognitive psychology and artificial intelligence in there too. It would be a great pity if too much spice caused conventional researchers to dismiss the journal altogether. But it is pleasant that we are promised discussions in the humanities as well as in science, with papers on cultural aspects of consciousness and on the philosophy of mind slated for future issues. The journal will continue to have something for everybody.
So, the question arises: Has consciousness been explained? Is it likely to be explained any time soon? After a while, I found that I had a curious reaction. The approaches here are too wild for the easy problems, but not wild enough for the hard problem. When it comes to the explanation of cognitive functioning, conventional methods seem to do just fine, and it is hard to see why things like quantum mechanics need to be brought in at all. But when it comes to the hard problem of conscious experience, all the quantum mechanics and parapsychology in the world does not add up to a solution. Why should quantum coherence in microtubules give rise to conscious experience? This question seems no easier to answer than the corresponding question about information-processing in neurons. Radical as the approach is, it is ultimately not radical enough.
Still, a journal like this serves a useful function, both in stimulating
thought and in letting a thousand flowers bloom. After all, the problem
of conscious experience is so hard that when a solution finally appears,
it will probably look crazy. With an unconventional journal on the scene,
the required craziness will be given room to flourish.