The human mind is the single most fascinating mystery in the known universe, providing the intellectual impetus for the fields of neurology, psychiatry, and neuroscience. The publishers of Scientific American have found that their readers also share this interest. Scientific American's readable but sophisticated reviews have been a staple for the well-educated since 1845, just as the field of neurology was being founded by Charcot. In 2004 the bimonthly Scientific American Mind was launched to capitalize on the explosive advances in knowledge about the nervous system.
Now, in Best of the Brain from Scientific American, Floyd Bloom, former editor in chief of the journal Science, has collected 21 articles about the mind and brain into a monograph that provides a stimulating overview of this field.
The 270-page book is divided into three sections, which attempt to provide thematic cohesiveness to the articles. Any shortcoming in this attempt is overshadowed by the outstanding level of writing. With one obvious exception, the reviews were written by leading investigators such as Antonio Damasio, Eric Kandel, Fred Gage, and Steven Hyman, and their passion for explaining their own subjects in a readable manner succeeds. The level of the technical treatment will neither offend the expert nor induce somnolence.
As a neurologist, I found that the articles based on human diseases and neuroscience, such as “Rethinking the Lesser Brain” and “The Addicted Brain” made the most compelling reading.
A COMPELLING MYSTERY
In the first section “Mind,” the articles focus on underlying biological mechanisms. These articles have a rather speculative bent, merging concepts from psychiatry, neurology, and neurobiology. Ulrich Kraft notes in his article on creativity, for instance, that research supports left cerebral hemisphere dominance for “convergent thinking,” which attempts a single correct solution to a problem, and that damage to the left side of the brain can unleash the creative, or divergent, functions of the right cerebral hemisphere. He cites by example changes sometimes seen in frontotemporal lobar degeneration.
In “Stimulating the Brain,” Mark George introduces the concept of functional knockout, in which repetitive transcranial magnetic stimulation induces temporary alterations in focal brain function in healthy volunteers. He also offers an excellent overview of current applications of electricity for neurological disorders ranging from Parkinson disease to depression to seizure control.
A sidebar makes an interesting rebuttal to the Mark Solms article, which posits that Freud's psychoanalytic formulations such as the ego and superego can be explained by recently discovered functional localization of psychological characteristics. The author of the counterpoint disagrees rather strongly, clearly loathe to reintroduce Freudian psychoanalysis in this way.
In his article, “The New Science of Mind,” Antonio Damasio's concept of “movie-in-the-brain” is a fascinating view of the nature of self. Finally, notes about the personal aspects of discovery in neuroscience are a compelling part of Eric Kandel's article in this section.
“Matter” comprises the middle and largest section of the book, and it explores insights into brain function through the window of neurologic and psychiatric diseases. A particularly fine example is the recent research that redefines the cerebellum's main role as one of processing sensory information rather than in controlling movement. The differences in activation of the cerebella of rodents, cats, and monkeys by sensory stimuli involving whiskers, paws, and fingers, respectively, are remarkable.
In an article about the neural basis of sign language in the deaf, the authors point out that signing is unique because in addition to the usual considerations involving the language circuits in the brain, it involves a major component of spatial representation. The description of the effects of left and right cerebral brain lesions on signing made this one of my favorite articles in the collection.
Another wonderfully written article explores the topic of Huntington disease. Studies of the genetics and molecular biology of this horrific disease have lead to great strides in understanding its basis, but to date there is much less progress toward effective therapy, although the early attempts at the treatment are reviewed for the reader.
Some of the most exciting advances are in stem cell research. Fred Gage's vision of treatments that could switch on the innate capacity of the brain to replace its own cells is speculative but interesting. The list of potential drugs being developed for this purpose is quite remarkable.
Substance abuse is an extremely important problem worldwide, and for neurologists who have not recently reviewed the role of the ventral tegmental area, nucleus accumbens, and dopamine in substance abuse and addiction, an article titled “The Addicted Brain” will be an outstanding review of reward circuitry.
The final section of the book, titled “Tomorrow's Brain,” includes several articles that examine the development of brain-machine interfaces (BMI). The potential ability of future computers to function like the human brain as described by Ray Kurzweil in “The Coming Merging of Mind and Machine” is thought-provoking. Of more immediate practical importance is the rapidly developing ability to control computers and robots directly through brain activity, and this field is described in several excellent articles.
The book concludes with a description of current research in new areas of pharmacology that seeks to improve brain activities such as memory and attention. While there would be obvious therapeutic applications for such agents in patients with diseases such as dementia, the potential for off-label use of the drugs to “allow normal individuals to sleep less, work harder and play more” is clearly an issue with ethical ramifications.
This book provides a fascinating tour of recent advances in studies of the brain and mind and also includes thoughtful speculation about the future of this area. Scientific American's approach of having experts in these fields write about their own area of work keeps the quality of the articles at a high but readable level.