William Calvin, otherwise known as “That guy who talks about throwing a lot”, is one of my favorite popularizers of neuroscience. The Cerebral Symphony (1989) is an attempt to explain what it is that makes human consciousness so special. One of my favorite things about Calvin’s approach to human consciousness is that, in his view, “The term should capture something of our advanced abilities rather than covering the commonplace” (p. 78). In other words, the primary explanandum of consciousness studies is not the “sensory qualia” we share with nonhuman animals, but rather, our ability for abstract thought, imagination, and “mental time travel”. That is, Calvin is trying to explain the more “narratological” aspects of consciousness (to borrow a term from Julian Jaynes, who Calvin cites approvingly on this issue) as opposed to the more sensorimotor aspects. However, being a Darwinian, Calvin doesn’t want to necessarily say that capacities that make humans able to narrate and imagine sprung out of evolutionary thin air, so perhaps there are some functional overlaps with other primate species.
The central explanatory tool of the book is what Calvin calls a “Darwin Machine”, which is a variant of the “neural darwinism” approach to brain function. Calvin’s idea goes something like this: suppose the evolution of the ability of humans to throw (and thus hunt more efficiently) necessitated the development of a “neural sequencer” that plans linear motor patterns. Now imagine you have a massive array of sequencers operating in parallel but generating different “variations on a theme”. Calvin’s idea is that consciousness is the sequence that best survives based on various selection criteria that change depending on the task at hand. This is in fact very similar to Dennett’s notion of “multiple drafts” or “fame in the brain”, and I think I first heard of Calvin’s book in Dennett’s 1991 book Consciousness Explained. To me it sounds like pretty much the same theory, which limits the originality of Dennett’s theoretical framework (supposing that Calvin came up with the idea first). Overall, The Cerebral Symphony is an interesting and theoretically insightful account of human consciousness that is solidly grounded in Darwinian thinking (perhaps to a fault). The book is also interspersed with sociological commentary on the scientific community at Woods Hole in Cape Cod Massachusetts, which makes for relatively easy reading.