October 27, 2008

October 27, 2008

Dear LoMA Family,


I’ve been reading Norman Doidge’s new book, The Brain that Changes Itself. It’s an amazing summary of the latest in research about how the brain works. Neurons are the brain cells that make us smart - the more robust they are and 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 mice 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 neurons that were 25% larger and better connected than the lazy rats. Given the opportunity, rat neurons grew to solve problems set before them and physical exercise delivered more oxygen-enriched blood to help the neurons grow. 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 had known about these experiments, Doige’s book taught me that brain theory about neurons has recently gone through a change. 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 famous example of this, scientists sewed shut the eyes of a newborn kitten. When it was one-year old, they cut the 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 neuron networks can also be a problem if they become become overly stimulated (this may be the problem with autistic people). To prevent this, the brain is constantly trimming and shaping and shaping its neurons. While neurons grow best when children are young, adolescence is time of massive cutting back of neurons. Because children’s brains want them to try everything, they are too unfocused to concentrate on higher level math or reading. In adolescence, the brain determines which neurons to trim so that we can think more clearly. In making this decision, the rule the brain follows is 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 so important that high school students be given as much demanding, thought-provoking work as it can handle. The more difficult math problems students do, the more challenging books they read, and the more vocabulary they learn now, the smarter they will be for life. It is not too late yet…but soon it will be.


Exercise your brain,



John Wenk