26/01/2009 by admin.

An article in the New Scientist by Linda Geddes (here) talks about what gets our attention – it is surprise. Pierre Baldi and Laurent Itti have been investigating surprise.

A dominant theory from the 1950s has it that the amount of attention we pay to an object or event is linked to the volume of information our brains need to form an understanding of it. For example, our attention should hover over intricate patterns longer than over a plain surface…. To test their hypothesis (that it was surprise rather than volume of information that prompted attention), the pair developed a computer model which simulated a population of visual neurons “watching” video clips, just as your brain would watch it through the eye’s retina. They used the model to analyse short video clips and mark which regions of the videos it considered the most surprising - which they rated in wows. “Something that is very surprising has a high wow content,” says Baldi.

…When they showed the videos to human volunteers, their eye movements correlated with what the computer had rated as being worthy of attention. “We found that human observers did indeed look at surprising things while watching TV, much more than they looked at information-rich objects,” says Itti… a Bayesian theory of surprise in which an event is surprising if it changes our beliefs.

This idea fits with the notion that we predict the near future and compare our prediction with the actual events. Surprises show deficiencies in our model of reality. These deficiencies would need to be corrected.

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