The Brain That Changes Itself (8)

Enriched environments and stimulation lead the brain to grown. Over the years his labs and others have shown that stimulating the brain makes it grown in almost every conceivable way. Animals raised in enriched environments --- surrounded by other animals, objects to explore, toys to roll, ladders to climb, and running wheels --- learn better than genetically identical animals that have been reared in impoverished environments. Acetylcholine, a brain chemical essential for learning, is higher in rats trained on difficult spatial problems than in rats trained on simple problems. Mental training or life in enriched environments increases brain weight by 5 percent in the cerebral cortex of animals and up to 9 percent in areas that the training directly stimulates. Trained or stimulated neurons develop 25 percent more branches and increase their size, the number of connections per neuron, and their blood supply. These changes can occur late in life, though they do no develop as rapidly in older animals as in younger ones. Similar effects of training and enrichment on brain anatomy have been seen in all types of animals tested to date.

孟母三迁的生理学原因。看来创造环境对孩子的成长是十分必要，也是非常重要的。