From the website:
Imagine...
A passer-by asks you for directions. As you talk to him, two workmen walk between you carrying a door. In a flash the passer-by switches places with one of the workmen, and you are left giving directions to a different person. Do you think you would notice?
Researchers at Harvard University played this trick on some unsuspecting people and over 50 per cent failed to spot the change.
This phenomenon is known as "change blindness" - only a tiny fraction of all the information going into your brain enters your consciousness. People often fail to see a change in their surroundings because their attention is elsewhere.
Even stranger, if you are concentrating on something, you can become blind to other events that you would normally notice. This "inattention blindness" is possibly the reason why motorists collide with cyclists.
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