UCL in the News: Artificial brain falls for optical illusions

It suggests the illusions are a by-product of the way babies learn to filter their complex surroundings. Researchers say this means future robots must be susceptible to the same tricks as humans are in order to see as well as us. …

An object may appear brighter or darker, either because of the shade of its colour, or because it is in bright light or shadows.

The brain learns how to tackle this through trial and error when we are babies, the theory goes. …

Until now there has been no way of knowing whether this theory is correct. Beau Lotto and David Corney [UCL Institute of Ophthalmology] think they have finally done it.

They created a program that learns to predict the lightness of an image based on its past experiences - just like a baby. And just like a human, it falls prey to optical illusions. …

The researchers then tested the program on lightness illusions that would fool humans. …

Just like humans, the software predicted the objects to be respectively lighter and darker than they really were. It also exhibited more subtle similarities - overestimating lighter shades more than darker shades. …

"We didn't evolve to see things accurately, but to see things that would be useful," Lotto points out.

That has implications for robot vision. Most creators of machine vision try to copy human vision because it is so well suited to a variety of environments. The new findings suggest that if we want to exploit its advantages, we also have to suffer its failings. It will be impossible to create a perfect, superhuman robot that never makes mistakes. …

David Robson, 'New Scientist'