h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

"on the right hand sid"

Interesting article. There are some astounding things we can find out about the brain when parts of it go wrong. The most amazing example I heard of was to do with aphasia - the inability to use language. The experiment goes as follows: The experimenter says a sentence (or it is played on tape), and you have to press a button (or bang the table) as soon as you hear the word (for example) 'guitar'. At least in the example I heard of, people with aphasia are able to do this just from the sound of the word. So, with a healthy subject, you test them on sentences such as:

"The crowd was cheering, the rock star picked up his guitar." (normal)
"The crowd was cheering, the rock star slept his guitar." (gramatically incorrect)
"The crowd was cheering, the rock star buried his guitar." (makes sense gramatically but is an unexpected meaning)

With a healthy subject, the reaction time to the word 'guitar' is slower in the two strange cases, since we're not expecting the word. The really weird thing is that the reaction time for people with aphasia is *also* slower on the strange cases. This means that some part of their brain (at least in the cases I heard of) *does* understand whats going on, even to the extent of knowing the burying a guitar is a weird thing to do, but their conscious mind is not allowed access to this information.

Weird stuff.

I once heard an interesting analogy when discussing this kind of thing. Suppose you have a bunch of portable TVs from the same manufacturer, of the type commonly sold for 20 quid. Now, some of these TVs have been damaged - with a particular capacitor being removed. All these TVs start to whistle horrendously.

"Aha", thinks the engineer trying to investigate the mystery of the portable TV, "that component must be the whistle-inhibitor!". The guy who designed the TV might have a rather different view...