October 31, 2016
Dear LoMA Family,
I’ve been reading Norman Doidge’s book, The Brain that Changes Itself. It’s an amazing summary of the latest in neural research about how the brain works. Neurons are the brain cells that make us smart – the more robust they are, the better they connect to each other, the smarter we are. These neurons grow very similarly to muscles. The more they are used, the more they grow. In one experiment, scientists put one set of rats in a stimulating cage with wheels, toys and mazes that required them to do a lot of thinking and exercise. Another set of rats were given all the food they wanted and did very little. When they killed the rats and studied their brains, they found that the active rats had much more robust neural networks for two reasons: the physical exercise the active rats performed delivered more oxygen-enriched blood to the brain and thus helped the neurons grow; and the more the rats had to problem solve the more the neurons grew. Experiments on humans (that don’t involve brain autopsies) confirm that the more stimulating a person’s environment, the more robust the neuron networks become. A stimulating human environment, however, doesn’t have mazes, cages and wheels; it has challenging academic classes, interaction with the arts, and a demanding gym class.
While I knew about these experiments, Doige’s book taught me one area of brain research that has changed significantly in the last twenty years. When I was learning to be a teacher, I was taught that most neurons have a critical growth period in young childhood, and if they don’t grow by the time adolescence sets in, then it’s often too late. In one gruesome example of this, scientists sewed shut the eyes of a newborn kitten. When it was one-year old, they cut sutures. but the kitten remained blind for life because that visual part of the brain developed into something else, and the opportunity to learn to see had passed. In humans, a similar dynamic occurs with language acquisition. My niece learned English within six months of coming to America because she was nine years old; her mom, however, struggled for three years before becoming fluent. The evidence always seemed to support that the younger we are, the faster we learn.
The new evidence, however, shows that learning is more complicated than this because robust neural networks can actually be a problem if they become overly stimulated . For example, young children’s brains want them to try everything making them too unfocused to concentrate on complex problems like higher level math or reading. To prevent this overstimulation, the brain is constantly trimming and shaping its neural connections especially in adolescence when the brain follows a rule of use them or lose them. In other words, adolescence, not childhood, is the most critical period for developing higher-order thinking skills because it is the period when the brain is deciding which neurons are most important: the ones for watching TV and gossiping, or the ones for critical thinking. This is why it is important that high school students be given as much demanding, thought provoking work as they can handle. The more difficult math problems students do, the more challenging books, they read, and the more vocabulary they learn now, they smarter they will be for life. It is not too late yet, but soon it will be.
Exercise your brain,