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Ask Dr ? Jeffers

This month Dr. Jeffers is answering questions about the human brain and how it works．

Dear Dr. Jeffers,

One of my colleagues, Felix Moeller, told me that scientists are learning to use computer to 'read minds'．Is there any truth to this story?

—Jane Leon , New York, USA

Dear Ms．Leon,

Well, a lot of research is being conducted in this area, But so far, the brain scanning equipment and corresponding computer programs haven't been able to actually read thoughts．In one experiment, test subjects（受試者）were connected to scanning equipment and shown two numbers on a screen．They were then asked to choose between adding or subtracting（減）the two numbers．Using this method, researchers were able to follow brain processes and make the correct assumptions（假設）70 percent of the time．It's not quite mind reading, but it's certainly a first step．

—Dr． J．

Dear Dr. Jeffers,

My three-year-old son loves it when I dig my fingers into his sides and tickle（胳肢）him until he laughs uncontrollably．The other day I noticed him trying to tickle himself but he couldn't do it．Why not?

—Glenn Lewis, Vancouver, Canada

Dear Mr. Lewis,

It's because of how the brain works．The brain is trained to know what to pay attention to and what to ignore．It causes us to ignore physical feelings we expect to happen, but it causes a mild panic reaction when there is an unexpected feeling．For example, you don't notice how your shoulder feels while you're walking down the street．But if someone comes up behind you and touches you lightly on the shoulder, you may jump in fear．It's that unexpected part that causes the tickle reaction．

—Dr． J．