The Brain that Changes Itself - Norman Doidge (2007)

I found The Brain that Changes Itself by Norman Doidge up in Whitefish, Montana, and was surprised that I had somehow missed it in the past.  I take my usual exception to the wording of the title - brains don't change themselves - rather people can guide their own brain re-wiring.  This book is a great round-up of the current knowledge around neuro-plasticity - the ability to essentially regain or enhance ones mental capabilities (re-wiring one's brain), whether in response to injury or through conscious efforts.

The book opens with a couple of interesting observations, which I think point out the potential danger of metaphors.  Doidge traces the idea that the brain cannot change to three causes - lack of recovery in many brain-injured patients, lack of direct visibility of brain changes, and "the idea - dating back to the beginnings of modern science - that the brain is like a glorious machine.  And while machines do many extraordinary things, they don't change and grow." (p. xviii).

The book traces findings of many scientists who are studying the possibilities of brain regeneration.  For a long time the theory of localization - that each area of the brain had its own task and couldn't really change - held sway, but the evidence seems pretty overwhelming at this point that indeed areas of the brain can re-wire.  Many of the findings seem to indicate that it takes dedicated effort, and sometimes deliberate constraints, to force the person to find ways to use weakened parts of the body rather than relying on the still-functioning areas (for example, after a stroke when one side of the body may be partially paralyzed, one must find ways to exercise the weak side).  Many of the personal stories here are quite inspiring, showing results thought to be impossible in the past.

For most brain functions, the rule appears to be "use it or lose it" - i.e. one must keep exercising the functions of the brain or else the areas will atrophy.  This applies both to body movements and to mental capability - it appears that both physical and mental exercise are critical to maintaining a sharp mind and brain. 

While much of the focus of the book is on recovery from disability, there is some coverage of tools that may be useful in sharpening the performance of 'normal' folks (one example is the software of Posit Science).  I think there is still so much we don't understand about our own capabilities!