Nilesh Jasani's Reviews > The Idea of the Brain: The Past and Future of Neuroscience

"The Idea of Brain" is superficially a comprehensive journey through the history of neuroscience, chronicling our evolving understanding of the brain's functions and structures. While the book offers a wealth of information and historical context, it leaves the reader with nearly no answers about the nature of human cognition, which is more a function of where the field is and not necessarily any fault of the author. Every early theory is comprehensively debunked, which raises the point of the value of learning about them. The author keeps the tales of misconceptions engaging, but that cannot remove the questions on the utility of such knowledge.

The author masterfully navigates through the annals of Western philosophy, the Renaissance, and the scientific discoveries of the Enlightenment, illustrating how these periods influenced our thoughts on brain function. For instance, early theories likened the brain to a hydraulic system, influenced by the mechanical inventions of the time. This analogy, while imaginative, was eventually proven wrong as our understanding deepened. Similarly, the concept of the brain as a telegraph system in the 19th century was another compelling yet incorrect metaphor. Of course, we now want to learn about brains working through the knowledge of neural nets. The odds are against us, even if we can create machineries that rival natural neural nets across abilities.

The author also weaves together insights from philosophy, biology, psychology, and technology to illustrate how conceptions have changed over centuries. Even through what turned out to be false, one does get occasional good insights. For example, the idea of a strictly localized language center (Broca's area) was eliminated to give way to a more nuanced understanding of distributed language processing across the brain.

Apart from Aristotle, Descartes, and Darwin, one encounters the ideas of Freud and Jung—more interesting, even if equally incorrect. Anything one has read as a simple explanation—like the amygdala as the center of fear processing or the left brain for logic—is shown as wrong.

Advancements like functional MRI or fMRI meet the same fate. The early enthusiasm for fMRI studies has been tempered by recognizing their limitations in precisely localizing cognitive functions. Even where fMRI can show where brain activity occurs, it cannot explain how these regions contribute to specific cognitive functions.

The author appears ambivalent about whether brain functions can ever be explained in human languages. He is mostly sympathetic and hopeful with those who believe there is much to learn without learning about the detailed neuronal activities. To this reviewer, the mere existence of the vast number of neurons and their intricate connections underscores why reductionist approaches to explaining cognition will almost always fall short. The recent advances in neuroimaging, such as those from projects like the Human Connectome Project, almost prove the staggering complexity and dynamic nature. They underscore how any reductive effort, even partially to explain any brain function, will prove futile.

In other words, evolution has equipped us with a brain featuring tens of billions of neurons. If one reposes complete faith in evolutionary forces, it suggests that more straightforward, more structured explanatory models will likely be insufficient for the cognitive demands placed on our species.

In conclusion, if one is comfortable not having any definitive answers about the nature of cognition, the book is a good read about everything the brain is not. In fact, it is a masterpiece for those who want to debate any assertive claim made by anyone on any aspect of cognition.