Brain New World: The Brain Supremacy: Notes from the Frontiers of Neuroscience
by Kathleen Taylor
Oxford University Press, 2012 ($29.95)

What if our thoughts could be plumbed by a brain scanner and memories manipulated with the flip of a genetic switch? Neuroscientist Taylor believes these science fiction–like scenarios could become reality because new technologies may soon allow unprecedented access to our brains.

Taylor begins The Brain Supremacy by contemplating a future in which we can decipher others' private emotions and ideas as well as sculpt designer minds. Scientists can already decode single words and reconstruct mental images using functional MRI. We also tinker with brain activity on a daily basis by consuming mood-altering chemicals, such as caffeine and alcohol. More targeted neural enhancements, which might involve inserting new genes or modifying existing ones, could improve not only our cognition but also our personality, fashioning more law-abiding citizens or devoted spouses.

The intended appeal of The Brain Supremacy may be its future-focused musings, but this is the weakest part of the book. Though compelling in theory, Taylor's predictions fall flat because, as she admits, we are nowhere close to creating the tools or understanding the brain sufficiently to probe it in such depth. For instance, her critiques of fMRI make it clear that the technology is not equipped for full-fledged mind reading; it is too slow to catch moment-to-moment neural activity, and its data are often too crude to interpret.

Taylor's richest material lies in her explanations of what neuroscience can do now. She crafts an elegant guidebook on current technologies and methods for studying the brain, comparing the capabilities of different approaches and conveying the tedium of most day-to-day science. She describes her early research using rats to model activity in a part of the brain that processes touch. Her team inserted electrodes into the rats' brains and injected chemicals to observe how sensory receptors responded, then extracted the brains for analysis. The ability to probe and tinker with a brain in this way is invaluable in our search for knowledge.

Taylor does touch on research that could lay the foundation for more invasive and comprehensive cognitive enhancements. For instance, she reveals how investigators engineered mice to have a specific number of serotonin receptors, which are located in various brain regions and have been shown to affect the success of antidepressants. Mice with fewer receptors responded to Prozac, whereas those with many did not, supporting the hypothesis that simple genetic differences might explain why a drug works in some people and fails in others. This research showcases our potential to tailor drugs to an individual or tweak genes to make treatments more effective.

This comprehensive guide to the powers and limitations of neuroscience has much to offer, whether one agrees or disagrees with Taylor's predictions. Her goal is to intrigue and motivate further investigation, and she succeeds on that front.