As you read this review, your brain is undergoing changes by the millisecond. These words and sentences are stimulating ideas and emotions based on your brain’s current organization and content, which are reflective of all your experiences up to the present moment. Additional changes will occur as you proceed down this column of type.

Only recently did neuroscientists realize that the human brain exhibits such astonishing plasticity. This insight coincided with the introduction in the 1970s of modern brain-imaging techniques such as magnetic resonance imaging (MRI). With today’s sophisticated methods, including functional MRI, neuroscientists can capture in real time color-coded images of what happens in the brain during distinct mental states—even during “default states,” such as when we’re sleeping or daydreaming.

These advances have led neuroscientists to opine on subjects that were once the purview of philosophers, such as mind, self, and consciousness. But studying the self or consciousness is a bit like engaging in the childhood game of trying to jump on one’s shadow. While it seems doable, it isn't. Your movements change the position of your target. Fathoming mind, self, and consciousness presents similar paradoxes: The organ of investigation is the same as the organ carrying out the investigation; the processes employed are the same processes the investigator is seeking to understand.

Antonio Damasio, director of the University of Southern California’s Brain and Creativity Institute, admits as much in his illuminating book 

. But fortunately, there is a flip side to this conundrum. The development of the self and consciousness enables us to employ reasoning and scientific observation rather than depend on misleading assumptions.

For instance, some neuroscientists still believe that a specific site within the brain is responsible for self and consciousness. Damasio suggests instead that many brain sites, all active at once, are involved. He compares the situation to a symphonic performance in which the musical piece doesn't emerge from one musician or even one section of the orchestra. Instead, the orchestral conductor takes form as the performance unfolds: “For all intents and purposes, a conductor is now leading the orchestra, although the performance has created the conductor—the self—not the other way round.”

According to Damasio, we can best understand the brain as a series of maps that are “changing from moment to moment to reflect the changes that are happening in the neurons that feed them,” much like an electronic billboard on which the display can be “rapidly drawn, redrawn, and overdrawn at the speed of lightning.” Consciousness expands our ability to experience brain maps in the form of images that can be manipulated and reasoned about. In fact, the mind and consciousness partly evolve from the brain’s unceasing and dynamic mapping of these images. Incidentally, Damasio doesn't restrict the term image to the visual, but uses it to refer to “the brain’s momentary maps of everything and of anything, inside our body and around it, concrete as well as abstract, actual or previously recorded in memory.”

The fact that maps and images dwell within the brain and are accessible only to the owner presents a “hurdle” to scientific measurement, as Damasio admits. For this reason, the “mental state/brain state equivalence”—that is, the idea that the mind is indistinguishable from the operations of the brain—“should be regarded as a useful hypothesis rather than a certainty.” He cautions that even using neuroscience techniques more powerful than those currently available, “we are unlikely ever to chart the full scope of neural phenomena associated with a mental state, even a simple one.”

While most neuroscientists agree with Damasio that consciousness is rooted in biological processes, he goes a step further in emphasizing the importance of the body as a whole rather than the brain alone in the experience of consciousness. He concurs with other neuroscientists that consciousness contributes to adaptability and evolution, but he isn't afraid to make the surprising suggestion (although perhaps not surprising to some pet owners) that animals may possess a rudimentary form of consciousness.

I found Self Comes to Mind a delight. But despite Damasio’s attempts to address a general audience as well as other neuroscientists, readers with little knowledge about the brain may well experience the cognitive equivalent of seasickness. Still, all is not lost for first-time brain-book readers. Start with the appendix, a lucid summary of the main elements of neuroanatomy and neurophysiology. Next, read chapter 10, “Putting It Together,” in which Damasio sets out his main points minus the jargon-dense and peer-directed hairsplitting of earlier chapters. After that, you’ll be reasonably equipped to start reading this book from the beginning. If you do, you will embark on an intellectual journey well worth the effort.

 is the author of 20 books on the brain, including, most recently, 

The Playful Brain: The Surprising Science of How Puzzles Improve Your Mind 

"Self Comes to Mind: Constructing the Conscious Brain" 

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Only recently have neuroscientists realized the extent of the human brain's astonishing plasticity. 

Richard Restak