A brilliant illustration of the Kanizsa triangle made out of kiwi fruit by Flickr user Yves Moreaux.
The Kanizsa triangle is often used to argue that a purely ‘bottom-up’ approach to understanding vision – that says we generate our perception solely from building up from the small details of what we see – is flawed.
In this case, it seems we fill in the outline of the triangle partly based on our prior expectations, because if we follow the contours in the image, there isn’t actually a triangle there.
The triangle illusion is named after the Italian psychologist Gaetano Kanizsa.
Kanizsa was also an accomplished artist who created numerous paintings that played with the concepts of perception.
Link to Yves Moreaux’s brilliant Kanizsa kiwi.
Link to online exchibition of Kanizsa’s paintings.