The Idea of the Brain
Author: Matthew Cobb
The author of this book, a professor of zoology, set out ‘to explore the rich variety of ways in which we have thought about what brains do and how they do it’. In doing this, he evaluated the seminal discoveries made by ‘brilliant minds’ of the past, arguing that, in a grand journey towards unravelling the brain, each new idea emerged from the one that preceded it. In a strictly chronological approach, the book documented how our perspectives of the brain have been transformed by the ‘gradual accumulation of ideas and knowledge’ – evolving from the uninformed notions of prehistoric times to the inadequate but scientific models of today. The book promoted a concept of the inevitability of progress, reminiscent of the philosophy of Herbert Spencer, pointing out how often different scientists make the same discoveries almost simultaneously, and remarking that if one researcher ‘had not done this work, someone else would have done so at about the same time‘. However, despite the advances already made in neuroscience, the book’s overall assessment of the current state of our understanding of the brain is rather damning. In coming to this conclusion, the author particularly cited the lack of any recent ‘major conceptual innovation‘, and the absence of ‘clearer theories and ideas about how it all fits together’ (pages 2-9, 33, 172 and 257).
The key theme that emerged throughout the book is the evolution of the concepts of the brain over the ages. The author first scrutinised the ancient outmoded views of the brain such as the attribution of thought to the heart, an idea first put forward in the 4,000-year old Epic of Gilgamesh, and later adopted by early physicians including Aristotle, Herophilus and Erastrasus. The author pointed out that such erroneous notions went unchallenged for more than three centuries, until Galen’s anatomical experiments provided ‘decisive evidence about the role of the brain’ in thinking. The book reviewed subsequent models of the brain, from the ideas that depicted it as a machine, a telegraph, and a robot, through to the mathematically-driven but equally misguided representation of the brain as a computer – a framework advocated by such mathematicians as Walter Pitts, John von Neumann and Alan Turing (pages 15-25, 40-41, 175-200 and 207-225).
The theme of the book that best resonated with the contemporary understanding of brain function is that of electrical nerve activity. Tracing the origins of this model to the early 18th century, the book reviewed how Luigi Galvani used his observations to propose that ‘there was some kind of innate electricity in the nerve, which passed…into the muscle‘. An even more insightful and ‘far-reaching’ perspective on ‘the link between brain, thought and electricity‘ was provided by Alfred Smee, the polymath who the book said conceived of the brain in terms of ‘hundreds of thousands of tiny batteries, each of which was connected to a part of the body’. The book however attributed the definitive understanding of nervous electrical activity to Johannes Muller, ‘one of the nineteenth century’s greatest scientists’, and his students, Hermann von Helmholtz, Ernst Heckel, Rudolf Virchow and Emil du Bois-Reymond. Other landmark breakthroughs in understanding electrical nerve activity the author highlighted were those made by Charles Sherrington on synaptic function and reflex arc conduction; by Francis Gotch on the refractory period; and by Edgar Adrian on the ‘all-or-none’ nature of sensory nerve conduction. The development of the neurone doctrine was also groundbreaking, the author depicting it as ‘one of the greatest scientific achievements of the nineteenth century’; he credited this to Jan Purkinje, Gabriel Valentin, Robert Remak, and particularly Santiago Ramon y Cajal whose feat he characterised as ‘on a par with that of Vesalius’ (pages 61, 70-74, 134-140, 147-150, 128-131 and 166-170).
In portraying the models of the brain developed in the last 50 years, a period which saw the emergence of the combined field of neuroscience, the book highlighted the influential breakthroughs that have enhanced our understanding of brain organisation relating to memory, visual processing, brain networks and connectomes. For example, in tracing the progressive elucidation of memory function, the author referred to the early influence of the work of psychologist Donald Hebb who ‘set out key elements of what became the modern biological framework for understanding how the brain functions’, and whose experiments pointed to the synapse as the target of memory. The book then related the insights obtained by psychologist Brenda Milner from her in-depth study of Patient HM, ‘the most famous patient in the history of brain science’; the discovery of brain maps by John O’Keefe; and the identification of place cells by May-Britt Moser and Edvard Moser. It was however to the work of Eric Kandel on the marine snail Aplysia that the author attributed our fundamental understanding of ‘how neuronal activity changes during learning‘ and ‘how memory is created‘. Other relatively recent neuroscience breakthroughs and advances in the book included those made by David Hubel and Torsten Wiesel on visual processing; by Francis Crick and Christoff Koch on consciousness; and by Benjamin Libet on freewill (pages 207-220, 223-225, 233-235 and 348-356).
The book provided a most enlightening perspective of the methodologies that went into advancing our knowledge and understanding of brain structure and function. For example, the author demonstrated how the independent elucidation of new theories, by replacing the older tradition of simply accepting ancient ideas, opened the way for the conceptual breakthroughs made in recent times. To illustrate the significance of this process, first introduced by the cadaver dissections of Mondino de Luzzi, the author referred to the impact of the anatomical studies of Andreas Vesalius on the understanding of the brain. For example, the author pointed out that Vesalius demonstrated the error in Galen’s view that networks of blood vessels in the heart enabled animal spirits to enter the brain. Furthermore, the book chronicled how a ‘massive programme of dissection’ enabled Thomas Willis to logically speculate the the brain played a central role in mental abilities such as memory. The book also discussed the more modern neuroscience techniques that have advanced the field, from those of Avid Carlsson, Ulf von Euler, Julius Axelrod, Bernard Katz and Paul Greengard, to those of Roger Guillemin, Andrew Schally, Solomon Snyder and Candace Pert (pages 27-39, 288-301 and 348-356).
As expected in every scientific endeavour, the history of the evolution of ideas about the brain is replete with controversies and disputes. Amongst the most striking row explored in the book is the enigmatically titled ‘war of the soups and sparks‘. Depicting this as ‘one of the longest scientific disputes of the twentieth century’, the author explained that it pitched scientists such as John Eccles who argued for an electrical foundation of neuromuscular transmission, against researchers such as Henry Dale and Wilhelm Feldberg who maintained that it was a chemical process. The author recounted how this debate was finally resolved in favour of chemical transmission by the dream-inspired experiment of Otto Loewi. Of the earlier disputes, the 19th century conflicting perspectives of the concept of ‘localisation of function‘ stood out, and it pitched supporters such as Franz Gall and Ernest Auburtin, against deniers such as Marie-Jean Fluorens and Jean-Baptiste Boulliaud who viewed brain function as being ‘distributed across the cortex’. Other noteworthy historical controversies the book narrated included the one between Allesandro Volta and Luigi Galvani on the existence of animal electricity, and that between Camillo Golgi and Santiago Ramon y Cajal on the nature of nerve connections (pages 80-91, 150-153, 62-64 and 135-140).
This rather dispassionate history of the brain elucidates the evolution of the ideas of how and what the brain does, but it also provides enlightening biographies of the individual actors involved in the whole enterprise. The history it explores is a valuable account of the advances made in brain science, and it graphically illustrates the progression of ideas and concepts. The author also highlights the limitations of our current understanding of brain function which contrasts with the pace of historical advances. The book is disproportionately lengthy, a feature that is partly accounted for by the author’s rather detailed commentaries. Whilst this occasionally restricted the smooth flow of the historical narrative, it provided important context to the complex concepts that the book covers, typical of topics relating to the brain.
This book conveys an exhaustive history of our progressive understanding of the brain, tracing how erroneous ancient ideas were replaced, step-wise, by novel concepts. The books draws attention to the need to continuously question prevailing paradigms because the history it relates shows how frequently these get debunked. Whilst he provides a perspective of a fairly advanced state of the current understanding of the brain, the author nevertheless stressed the ephemeral nature of all scientific concepts and the need to regularly reappraise them. The book also raises concerns about what appears to be a slowing down in the development of new ideas, a phenomenon that threatens to perpetuate the ignorance that still pervades our understanding of the brain. The book’s lessons are relevant not just for neuroscience but for the whole of medicine, and I recommend it to all doctors.
Publisher, Place, Year: Profile Books, London, 2020
Number of chapters: 15
Number of pages: 470
Star rating: 4