American Scientist

An Anatomy of Thought: The Origin and Machinery of the Mind. Ian Glynn. viii + 456 pp. Oxford University Press, 1999. $35.

How does one begin to unravel the makings of mind? Ian Glynn takes us on a search through myriad historical accounts and recent discoveries that offer some insight into how the remarkable human mind works. This is a quiet, understated book. Glynn avoids bold claims of the sort made in some other recent books—for example, A Universe of Consciousness, in which Gerald M. Edelman and Giulio Tononi purport to sketch "the main outlines of a solution to the problem of consciousness" and establish a "new understanding of how consciousness emerges." Instead, Glynn takes a storyteller's approach, unfolding his stories in a scholarly fashion. His writing style is engaging, and the historical content will interest both general readers and specialists.

Glynn tells us in the preface that he wants to discuss the "worthwhile partial answers" that have been found to questions such as these: What kind of thing is mind? What is the relation between what goes on in the mind and what goes on in the brain? How did minds and brains originate? Are brains nothing more than very complicated machines? Can machines have minds? He takes as his starting position three statements: that minds exist only in association with the complex brains of humans and some other animals, that we and those animals are the products of evolution by natural selection, and that neither the origin of life nor its subsequent evolution has involved any supernatural interference. The second two statements are important, Glynn says, because the origin of brains is crucial, and he spends nearly one-fifth of the book justifying the statements in a primer on the evidence for evolution and the origin of life. By covering the evolution of Homo sapiens and the human brain, he begins at the true beginning, addressing the issues of where and when the essential properties of the human mind first arose.

Not until chapter six does Glynn begin to discuss the anatomy and physiology of the nervous system, providing us with a rare historical overview. He is a wellspring of knowledge about early research on the nervous system. "I have tried to say something about the observations, experiments and arguments that have led to current views," Glynn explains, "so that those views do not seem like the towers of Toledo at sunrise—ravishing but insubstantial, and resting on nothing but the mist over the Tagus."

The next three sections of the book—"Looking at Seeing," "Talking about Talking" and "Thinking about Thinking"—deal with vision, language and cognition. Here Glynn takes the reader on an Alice-in-Wonderland journey through mysterious phenomena of mind. The vision section includes visual illusions (for an example, see below), fascinating case histories of people with various agnosias illustrating the effects of neural damage, a discussion of blindsight (which involves taking in visual information without being aware of having any visual experience) and a description of an attempt to get networked computers to recognize faces. The language section includes characterizations of people with aphasias, alexias and agraphias; "split-brain" case histories; a discussion of Bickerton's studies of creole and pidgin languages in Hawaii; and descriptions of attempts to teach language to nonhuman primates. In the cognition section, memory, emotions, planning and attention are covered; Glynn concludes this section with a discussion of approaches to finding the neural correlates of consciousness, commenting that "these correlates seem as elusive as the crock of gold at the end of the rainbow."

If our questions about consciousness cannot be resolved by neuroscience alone, what else is needed? In the last section of his book, Glynn devotes his attention to what philosophy of mind has to offer, discussing behaviorism, functionalism, identity theories, eliminative materialism, propositional attitudes, qualia and free will. In rejecting eliminative materialism, he concludes that "the task of explaining conventional mental phenomena in terms of physical events in the brain has to be faced." Glynn lucidly points out that it is the subjective aspects of consciousness such as qualia that are least understood, and he speculates that Roger Penrose and Graham Cairns-Smith are correct in suggesting that fundamental advances in physics may be important to solving the problem of consciousness.

In a brief epilogue, Glynn sums up what he hopes he has clarified in his survey. He acknowledges the failure of science thus far to account for the existence of our sensations, thoughts and feelings, and he expresses doubt that we can count on progress in this area.

It is unfortunate that Glynn leaves us on such a pessimistic note, and perhaps his view reflects his omission of recent forward-looking theories of consciousness. In particular, Glynn has ignored theories relating neurotransmitters to consciousness. Theorists such as Elaine Perry and I have independently argued that the neurotransmitter acetylcholine plays a prominent role in consciousness.

Glynn offers no grand theory of his own and makes no apologies about this, simply stating, "I am not a sage." This may disappoint some readers; others will be charmed.—Nancy J. Woolf, Psychology, University of California, Los Angeles