Irrational eyes: seeing curves that aren't there30 March 2011
We can't always believe our eyes - we've all experienced visual illusions where our brains create visions of objects that aren't actually there. Why this happens is often explained in terms of our brains filling in the gaps logically: we see what is most likely to be there. However, Professor Bart Anderson, from the School of Psychology at the University of Sydney, has discovered new forms of visual illusions which cause the brain to create highly improbable shapes that aren't there.
In research published in the international journal Current Biology in March 2011, Professor Anderson, along with Judit O'Vari, a PhD student in the School of Psychology at the University of Sydney, and Assistant Professor Hilary Barth, from Wesleyan University, USA, presents new moving displays that make us see unnecessary contours.
The new findings challenge models that explain visual perceptions in terms of our brains 'seeing' the most optimal and probable visuals.
"If you look at these moving shapes, you see a really vivid illusion, in addition to the shapes which are really in front of you. For example, in the first animation presented here, we see a rectangular outline in white, with four solid grey circles moving towards and away from the rectangle, appearing to cover parts of the rectangle as they move. We also see a wave-like line that appears to spread outwards through each circle as it covers the rectangle, which seem to be connected between the four circles to create a roughly oval wave moving inwards and outwards," explained Professor Anderson.