Last week, I discovered a wonderful course, Learning How to Learn, from UC San Diego on Coursera. This course was taught by two prestigious scientists in neuroscience, Barbara Oakley and Terrence Sejnowski. After following the material from the first week, I feel the urge to take some notes of my own understanding.
What is learning
As far as our brains are concerned, learning something new means forming new neural pathways in the brain. The newly formed pathways are not strong, which is why we tend to forget new stuff more easily, but they can be strengthened by repeated practice of the new stuff we’ve learnt. Instead of intensive practice in one day, the best outcome could be achieved by arranging the practice sessions according to “spaced repetition”. For example, let’s say you are trying to remember a few new words from a foreign language that you are learning, you’ll get much stronger long term memory of the words if you study them 15 minutes on Monday, Tuesday, Wednesday, Friday and Sunday, rather than spend two hours studying them in one day.
Focused and Diffused modes
Our brains can operate in two different modes: focused mode and diffused mode. They are like the two sides of the same coin: one’s brain can either be in focused mode or diffused mode, but not in both. In focused mode, your frontal lobe cortex (the conscience self) is at work, and the neural signals mainly travel in existing pathways. For example, when a second grade student is working on elementary math problems, he/she is consciously using methods he/she already know to solve the problems. In diffused mode, for instance when your mind is wandering or you’re dreaming, the conscious self is not in control, so the neural signals travel more freely and widely. This mode helps the brain connects “unrelated” concepts together and forms new ideas or understanding.
It was believed human brain can hold up to seven items at one time, but recent researches have shown the number may be just four. Therefore, human brains are intrinsically not good at multitasking. Try not to work on two tasks at once. You’ll very like to fail at both tasks. In the interview, Dr. Sejnowski talked about his own multitasking. But what he meant was just quick context switching between multiple tasks, instead of actually doing two or more things at the same time.
The brain generate toxic products while you are awake. During sleep, the neurons will shrink, unblocking the stream, so that the metabolic toxins in the brain can be washed out by flowing fluid. Sleep is the brain’s way of keeping itself clean and healthy. Furthermore, the brain operates in diffused mode while you are sleeping, and rehearses what you have learnt during the day or before sleeping, which helps to deepen and strengthen the new neural pathways formed during focused mode studies earlier.
All the textbooks say that you get all your neurons at birth. When you grow up, new neural connections are made, but no new neurons are generated in the brain. The neurons may die, which means you have a shrinking cortex. But Rusty Gage discovered new neurons are born in the Hippocampus of an adult brain. The conditions being: a) an enriched environment, where you can communicate with other people and actively participate in events; or b) physical exercise. Exercises not only help make the body stronger, but also help the Hippocampus to give birth to new neurons and provide time for the brain to operate in diffused mode, which in turn benefits your learning.