One of these two images contains a hidden picture of a face. Which one?
This was the question faced by participants in a remarkable psychology experiment just published, Measuring Internal Representations from Behavioral and Brain Data.
Five healthy volunteers were presented with a series of random black and white grid patterns. Each grid square was either black or white, and this was randomly determined on each trial.
There was no pattern to the images, they were completely random. But the subjects were told that half of the patterns contained a hidden face, and that their job was to work out which ones did. Each subject saw over 10,000 random images and they took about 1 second to judge each one.
The volunteers "detected" a face in 44% of the images. Somehow, all five of them convinced themselves that they were seeing faces in many of the grids. The authors say ...
