What a Brain Scan Misses --- Neuroscientists proceed as if feelings, thoughts and desires -- elements of the conscious mind -- account for very little. But what if they have more 'agency' than mere neurons?

 

"The World Behind the World

By Erik Hoel

Avid Reader, 238 pages, $30

Imagine that you could shrink yourself small enough to be able to travel inside a brain. Hiking up the hippocampus or sailing around the cerebellum would no doubt be an awesome experience and well worth the trip. But nowhere would you be able to experience what the person with the brain was thinking, hearing or feeling. The buzzing hive of conscious life would be, to you, just a collection of cells.

The limits of such a fantastic voyage point to two seemingly irreconcilable ways of viewing ourselves: as biological matter and as self-aware mind. The contrast has stumped philosophers and scientists for centuries and is sometimes framed in terms of the objective and subjective, the external and internal. Neuroscientist Erik Hoel, taking up these two realms of human self-perception, calls them the extrinsic and intrinsic perspectives. In "The World Behind the World," he tries to explain why they exist, how we might try to bring them under a common understanding and why we might never fully succeed. On top of that, he attempts to rebut the argument, ever more frequent these days, that the firings of neurons -- not thoughts and desires -- are the only real causes of human action. As if that weren't enough, he tries to save the idea that we have free will too -- all in slightly more than 200 pages. His project is, he admits, "impossible in scope," but he still has the chutzpah to give it a go.

Mr. Hoel begins by challenging the idea that the dual perspective -- inside and outside -- has been a perennial, unchanging feature of human experience. He argues instead that the intrinsic perspective took a while to come into its own. Since the time of Homer, he says, our ability to describe and express our inner world has developed considerably. The first stirrings can be seen in ancient Greek writers like Simonides, who developed the "memory palace" method of memorization, and Euripides, who gave voice to the inner lives of his characters. This perspective languished during medieval times, Mr. Hoel says, but was given new life in the Renaissance by writers like Cervantes and developed yet more with the rise of the novel in the 18th century.

The argument is speculative and the timeline too neat, but the key point is well-made: Consciousness may be a human universal, but our desire and ability to articulate its qualities and recognize it explicitly as a distinctive perspective are human variables, not any more innate than our ability to study the world scientifically. And indeed, Mr. Hoel says, the rise of science, too, depended on our learning a perspective -- the extrinsic one. He gives an even faster whistle-stop tour of this process of development.

But then, in perhaps the book's most interesting chapter, Mr. Hoel changes tack and argues that the achievements of neuroscience -- the quintessential mode for extrinsic self-examination -- fall far short of what the hype and headlines suggest. 

We have been promised so much, as if the close study of the brain's collection of cells will yield a complete explanation for consciousness. 

The truth is, Mr. Hoel says, that mapping the brain's neuronal activity has provided us with very little predictive information. You cannot, for example, reliably tell if someone is depressed by looking at a brain scan. The brain is simply too malleable, too fluid in its structures and too complex for scans to pinpoint what does what at the neuronal level and what effects will arise from any particular pattern of neural activity.

But there is a deeper problem. Neuroscience has assumed that it can proceed purely by adopting the extrinsic perspective. However, as our hypothetical miniaturized journey around the brain shows, this perspective has severe limits -- almost by definition, it excludes consciousness itself. Neuroscientists carry on as though this exclusion doesn't matter. They tend to see consciousness, Mr. Hoel writes, as "some sort of minimal subsystem of the brain, possessing no information, almost useless. The steam from an engine." Mr. Hoel argues that "our very survival as an organism" depends on consciousness and its ability to track reality accurately -- or, as he puts it, on "the stream of consciousness being constantly veridical and richly informative." Nothing in the brain makes sense, he adds, "except in the light of consciousness."

At this point, Mr. Hoel has deftly set the stage for another whirlwind tour, this one surveying the theories of consciousness that have come out of both psychology and neuroscience. But here the going gets tougher. To mix metaphors, the reader faces a steep learning curve across terrain that is slippery at the best of times. It doesn't help that Mr. Hoel starts to use logic truth tables as though they were as easy to read as bar charts.

Mr. Hoel's principal focus is integrated information theory, developed by the neuroscientist Giulio Tononi. Its central thesis, crudely put, is that the more a physical system can integrate information, the more conscious it is. This integration -- the ability to combine different elements of information together -- is measured by a unit labeled "phi." If phi is figured accurately, the theory says, it can predict the levels of consciousness in any system: human, animal or machine. Mr. Hoel himself spent years working on integrated information theory but eventually became dissatisfied with it. It may describe certain key features of conscious systems, he felt, but it leaves consciousness itself unexplained.

Mr. Hoel is left with the somewhat pessimistic conclusion that, just as Godel showed that no formal system in mathematics or logic could ever be complete, perhaps science will never be able to account for the intrinsic perspective. But the reader is not left on this low note. The final chapters of Mr. Hoel's book defend the agency of conscious experience. The author is taking on those who insist that because all physical systems -- of which we are one -- inexorably follow the rules of cause and effect, free will is an illusion. His argument is complex and subtle, but at heart it amounts to the simple idea that what counts as a cause or effect depends on scale.

You cannot, for example, by analyzing the movement of individual atoms in the atmosphere, tell whether or not it's going to rain or blow a hurricane. You have to look at a larger, more-inclusive scale, the one of air-pressure systems and cloud formation. Because only events at this level can explain and predict weather events, we rightly say they are their causes. Similarly, patterns of individual neurons firing don't tell you how a person is going to act. But what someone thinks and feels may do so. These states of mind, Mr. Hoel says, are rightly called causes of action: They have "agency" in a way that mere cells do not.

As if he hasn't taken on enough already, Mr. Hoel finishes by tackling the thorny problem of free will. The ambition of this task is suggested by his conclusion: "Having free will means being an agent that is causally emergent at the relevant level of description, for whom recent internal states are causally more relevant than distant past states, and who is computationally irreducible." This is a perfectly reasonable suggestion, but it requires more than the 13 pages it is given to make its meaning clear, let alone to build a case for it.

"The World Behind the World" tries to do too much, too quickly, and as a result is at times hard to follow and at other times, although suggestive, not really persuasive. But it offers a series of bracing intellectual challenges and almost seems, in its concise presentations, like a set of teasing prose-trailers for at least half a dozen other books you'd love to read. Mr. Hoel is still young: He has the time and talent to write them.

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Mr. Baggini is the author of "Freedom Regained: The Possibility of Free Will."" [1]

1. REVIEW --- Books: What a Brain Scan Misses --- Neuroscientists proceed as if feelings, thoughts and desires -- elements of the conscious mind -- account for very little. But what if they have more 'agency' than mere neurons? Baggini, Julian. 
Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]. 22 July 2023: C.7.