Wednesday, January 28, 2009

Brain Rules

I just read John Medina’s book Brain Rules. It is a book about how our brains work. What I find most interesting is how it applies to learning.


Our brains are able to pay attention to three things. It can be characterized by these questions.

  • Does it want to kill me?
  • Can I have sex with it?
  • Does it remind me of anything?

All three questions are relevant to how you give a presentation. If everyone seems to be dozing off they can be awakened by I sudden sound or a picture of something sexy. But these measures are just that, attention grabbers, and if a presentation is so boring that I have to slam the table all the time I’m definitely doing something wrong.

The third question: Does it remind me of anything? is different. It is very important both to giving presentations and to learning. If I can find a way while giving a presentation to have the audience relate to my subject in any way, they are more likely to pay attention. It’s the same with learning. If I’m learning something that reminds me of something else it will be easier for me to put it in a context that means something to me and that will enable me to learn it much better.

I find this very interesting since lately I’ve found that I like doing things that I suck at. The things I like and suck at are very diverse. I have started to like skateboarding, playing Guitar Hero, and even carpentry. I think that it is because I know more now and even if I’m no good at these things they remind me of other things that I’m better at. And just as important, they widen my frame of reference, so next time when maybe I have to weld something I wont find the entrance barrier to high to even imagine doing it. The more I recognize, the more I relate to, the more I like. It is a good loop.


In the book Medina also talks about memory. There are, at least, two kinds of memory, short-term memory and long-term memory. The short-term memory is our working memory and it is good for very short periods of time. To store something in long-term memory, repetition is required. The more I repeat something, the better I will learn it.

The best books I have read that take advantage of repetitions without being boring are The Little Schemer-series, The Little Schemer, The Seasoned Schemer and The Reasoned Schemer. These books are built up as a series of questions in one column and the answers in another. The difficulty increases gradually as you read more.

The point of The Little Schemer is to teach to think recursively in Scheme. It does a great job of teaching this, probably because of all the repetitions that are involved.

The point of The Seasoned Schemer is to teach more advanced concepts of functional programming in Scheme, such as continuations.

The point of The Reasoned Schemer is to teach logic programming in a functional context.

It is interesting that the concepts taught in the books are quite complex and still they never feel hard when presented in this way. I highly recommend them to anyone.

Another interesting thing about repetition is that it seems to be happening while we sleep. When we are sleeping our brains keep repeating things that we learned during the day. After going to sleep while reading The Seasoned Schemer, I remember waking up one morning and finally getting how continuations work. Quite a good feeling.


Stress affect learning in a bad way for almost everybody. Stress is defined, to allow researchers to measure it, as having three criteria.

  • It has to create physical arousement.
  • If you could avoid it, you would.
  • It has to feel like it is out of your control.

If any of the above is true, it is said to be stress. When we are stressed our brains cannot focus on the task at hand and this will decrease our learning abilities severely.

You can also listen to John Medina talking about the book on the Ruby on Rails Podcast.

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