I value Doctor Merzenich work and how it has helped so many, but this book was a disappointment. A tiny bit of science, a moderate amount of anecdotal evidence (written in a boring way), and a lot of advertisement of his own tool to promote neuroplasticity.
At least he acknowledges it: "this book may sound a little like an advertisement. But my own motive is a simple one: these programs represent the grand product of my life's work."
If you want to learn about neuroplasticity, read Norman Doidge's "The Brain that Changes Itself"