More than meets the eye
We experience countless illusions in our lifetime. The most famous being geometrical illusionsthose with converging lines and a vanishing point we often see in Psychology 101 classes or in entertaining optical illusion books.
To picture one, think of the Hering illusion, which looks like a bike spoke with two vertical lines drawn on either side of the center vanishing point. Although the lines are straight, they seem to bow out away from the vanishing point. The optical illusion occurs because our brains are predicting the way the underlying scene would project in the next moment if we were moving in the direction of the vanishing point.
Evolution has seen to it that geometric drawings like this elicit in us premonitions of the near future, says Changizi. The converging lines toward a vanishing point are cues that trick our brains into thinking we are moving forwardas we would in the real world, where the door frame seems to bow out as we move through itand we try to perceive what that world will look like in the next instant.
Beyond geometric, Changizi was able to identify 27 other classes of illusions. He organized them into 28 predictable categories classified on a matrix that distributes them among four columns based on the type of visual feature that is misperceived (size, speed, luminance, and distance) and among seven rows based on the different optical features that occur when an observer is moving forward.
He then culled hundreds of previously documented illusions to test whether they would follow the appropriate prediction as determined by the table, and found that they did, indeed, follow the patterns he laid out in the matrix.
This new organization of illusions presents a range of potential applications, including more effective visual disp
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| Contact: Amber Cleveland clevea@rpi.edu 518-276-2146 Rensselaer Polytechnic Institute Source:Eurekalert |