Winnie Lim

environmental deprivation could shrink the brain…In examining cats raised with one eye sewn shut, they found that the visual cortex was significantly smaller.

experiments with lab rats suggest that forced exercise doesn’t do the trick quite like voluntary exercise.

It turns out that moving our muscles produces proteins that travel through the bloodstream and into the brain, where they play pivotal roles in the mechanisms of our highest thought processes.

the point of exercise is to build and condition the brain.

At the end of the study the subjects who had done physical exercise increased their muscular strength by 30 percent, as one might expect. Those who only imagined doing the exercise, for the same period, increased their muscle strength by 22 percent.

imagining an act and doing it are not as different as they sound. When people close their eyes and visualize a simple object, such as the letter a, the primary visual cortex lights up, just as it would if the subjects were actually looking at the letter a. Brain scans show that in action and imagination many of the same parts of the brain are activated. That is why visualizing can improve performance.

Pascual-Leone found that both groups learned to play the sequence, and both showed similar brain map changes. Remarkably, mental practice alone produced the same physical changes in the motor system as actually playing the piece. By the end of the fifth day, the changes in motor signals to the muscles were the same in both groups, and the imagining players were as accurate as the actual players were on their third day.

Pain and body image are closely related. We always experience pain as projected into the body. When you throw your back out, you say, “My back is killing me!” and not, “My pain system is killing me.” But as phantoms show, we don’t need a body part or even pain receptors to feel pain. We need only a body image, produced by our brain maps. People with actual limbs don’t usually realize this, because the body images of our limbs are perfectly projected onto our actual limbs, making it impossible to distinguish our body image from our body. “Your own body is a phantom,” says Ramachandran, “one that your brain has constructed purely for convenience.”

Merzenich thinks our neglect of intensive learning as we age leads the systems in the brain that modulate, regulate, and control plasticity to waste away.

And if maps could change, thought Merzenich, then there was reason to hope that people born with problems in brain map–processing areas—people with learning problems, psychological problems, strokes, or brain injuries—might be able to form new maps if he could help them form new neuronal connections, by getting their healthy neurons to fire together and wire together.