All brain activity is of the same kind – there are no special neurons for vision, hearing, touch etc. Perhaps the most stunning example of the brain's surprising powers is sensory substitution. These are quite complicated ballistics equations, but we have no conscious control or knowledge of them, since most of the brain's work is unconscious.Įagleman demonstrates these perceptual processes with an array of deceptive figures, some already very familiar, such as the vase-and-two-heads illusion, and case histories. The brain is able to compute trajectories based on past experience. This explains how a batsman can hit a 90mph ball or how a fielder sprints to catch a skyer falling many yards away from him. We see with the brain, not the eye, and the brain generates expectations of what is out there, which are then modulated by the signals coming in. Eagleman gives countless examples to demonstrate that vision is not a passive process – the eye and brain a camera – as it appears to us. The brain offers a seamless impression of reality, but that is an illusion. These tricks (including an ingenious dust-jacket) make up the bulk of Incognito. In the other: you think your brain and senses reveal the world as it is? He will show you the tricks they play on us. In one, he delineates, with remorseless logic and clarity, what any conceivable afterlife would actually entail. If salvation is his goal, his method in both Sum and his new book, Incognito, is to ask us to cast off our lazy, commonplace assumptions. Finally, in his professional and academic capacity as a research neuroscientist, he believes that the new knowledge of the brain can help solve one of our most intractable problems: how to turn bad people into good – how to rehabilitate criminals. His exclusive iPad app, Why the Net Matters, is concerned with saving us from the kind of Jared Diamond-style collapse that has befallen every previous civilisation (the net is a worldwide alerting system, a mass data collector, a hedge against the loss of knowledge in an Alexandrian library-type disaster, and a subverter of tyranny). Sum, his bestselling collection of short fables ('You will not read a more dazzling book this year' tweeted Stephen Fry) asked us, in the most rigorous and stark manner, to be careful what we wish for in the afterlife.

D avid Eagleman is much possessed by ideas of salvation.

Incognito by david eagleman