91Èȱ¬

Human Senses TV Programmes

Programme 2 - Vision

Nigel Marven sets out to discover why we are excellent at seeing some things, but sometimes miss what's right in front of our eyes.

We only see what our brains want us to see

Humans' real speciality is checking each other out. We're so good at it, we do it without even being aware of it. With the help of the latest eye-tracking technology and scientists from Sussex University, we show some unsuspecting volunteers what their eyes really get up to.

We are also very skilled at gauging depth and distance. Nigel discovers how top baseball players manage to track a ball coming towards them at high speed. This skill is an extreme example of the basic hand/eye co-ordination that we all acquire as we grow up. To see how it feels to be back at square one, Nigel spends a day with eccentric Professor Hubert Dolezal in Chicago, to experience the professor's 'upside-down goggles'.

Almost a third of our entire brain is devoted to vision, but there's a limit to how much our eyes observe. In a simple experiment in a busy shopping centre, Nigel asks shoppers for directions and then switches places with someone else while the shopper is distracted. Most people failed to notice the switch and carried on giving directions. Dr Richard Wiseman of the University of Hertfordshire, explains that people's brains weren't paying attention to who was asking the questions because they were just concentrating on getting the directions right. So, ultimately, we only see what our brains want us to see.