This Google Talk presentation contains a wealth of fascinating facts about that capacity of the human brain and strategies to make the most of the brain's potential. It's 52 minutes long, but well worth the time it takes to watch (especially for New Zealand teachers who are on their summer / Christmas holidays).
However, if you find the Dr Medina's presentation style a little overpowering I have taken a summary of some key points, as given in the most useful Amazon review, of the book that he discusses in the talk. These key points can be found below.
I particularly like the information on the benefits of exercise to enhance the capacity of the human brain.
The points below were identified by Dr. James T. Brown in his Amazon review of John Medina's book.
I. Some parts of the brain are just like a baby's and can grow new connections and strengthen existing connections. We have the ability to learn new things our entire life. Medina states this was "not the prevailing notion until 5 or 6 years ago." So much for the "you can't teach and old dog new tricks excuse." The old dog line is exposed for what it really is...an excuse.
II. Humans can only pay attention for about ten minutes and then need some kind of reset.
III. The brain can only focus on one thing at a time. This is further rationale on the futility of multi-tasking.
IV. Exercise increases brain power and aerobic exercise twice a week reduces the risk of general dementia by 50% and Alzheimer's by 60%.
V. There is a biological need for an afternoon nap.
VI. The brain is very active during sleep and loss of sleep hurts cognitive and physical ability.