Every week on Jay's Brain I will feature a recent experiment that sheds light on how the brain works. The bonus is that the experiment will be set up so that you can take part.  

Have you ever noticed that the more complicated a sentence, the harder it is to grasp the meaning? That is exactly what was addressed by an experiment in the October 4th edition of the journal SCIENCE. Marcel Adam Just, Patricia Carpenter and their colleagues at Carnegie Mellon University in Pittsburgh showed that as sentences get more difficult, the brain recruits more brain cells to deal with them.

They used three kinds of sample sentences, each of which expressed the same meaning using the same number of words. The only difference was the arrangement of words. They then correlated the difficulty students had reading and understanding the sentences with magnetic resonance images of the activity of their brains. Sure enough - the harder the sentence, the harder the brain worked.

Here is how you can play along with this experiment. Read each of the following three sentences carefully one by one. The image beside each sentence illustrates the areas of your brain that are likely activated as you read.

The reporter attacked the senator and admitted the error.

The reporter that attacked the senator admitted the error.

The reporter that the senator attacked admitted the error.

There are two important features of this experiment. One is that there is a substantial increase in the amount of brain used as sentences get more difficult. We're talking about cubic millimetres of brain tissue, each of which contains hundreds of thousands of neurons.

Second, there is increased activity in both hemispheres. Increases in left hemisphere activity are expected - it is the main language hemisphere in most people. But more difficult sentences also aroused activity in the right hemisphere, usually considered a minor player in language.

It just shows how little we really understand about the brain.