If the century just passed was “the province of the gene,” then the next hundred years shall be “the province of the mind,” believes Eric Kandel. Brain science is poised to reveal the biology of conscious and unconscious mental processes involved in perception, emotion, thought and action. There will also be “a revolution in understanding mental illness,” with animal models revealing the “mechanism of pathogenesis.” We shall gain an understanding of the biological underpinnings of personal wellbeing, using imaging to reveal the pathways in the brain involved in joy. Scientists have singled out one gene that in such animals as voles determines whether they will socialize, or act as loners, suggesting the possibility of molecular insight into social and aggressive behaviors. What’s more, says Kandel, neuroscience will suffuse all the disciplines: sociology will have to consider a “biology of free will;” economics must take up the biology of decision and choice; art appreciation will have to account for how sensory information gets processed, such that when “two people look at the same object, one finds it beautiful and the other finds it boring.” And psychology will become indistinguishable from neuroscience, leading to a common base of training for neurologists and psychiatrists.

A contrary James Watson offers a dose of skepticism around the direction of brain research described by his colleagues. In the words of his old partner Francis Crick, “we haven’t found the double helix of the brain and don’t know how to think about it.” Some “gigantic problems” exist, says Watson: How is perceptual information stored; what does it look like; and how does information get pushed from one part of the brain to another? Key to cracking these questions, in Watson’s opinion, will be a deep understanding of brain evolution. He also recommends delving further into the genetic basis of mental disease, which might uncover an underlying defect in neurogenesis -- the growth of new brain cells. Perhaps all mental disease will ultimately be characterized as a “deep learning defect.” Watson is much concerned with “why we lose the ability to learn as we get older.” He believes it must be because “the brain is finite—we can only have so much stored.” But while he plays tennis and reads books partly in the hope that they will expand his mind, Watson also looks to biology for a way “to speed up neurogenesis in adults, and raise IQ.” Part 1 of this panel can be found here.