From Scientific American:
Perhaps all the time spent furiously hunting for the red- and white-stripe-wearing hider Waldo could have been avoided if his eventual spotter just glanced and pointed to the page. At least that is what is indicated by the findings of a new study conducted by researchers at University College London, which appears in the January 9 issue of Current Biology. Psychologist Zhaoping Li presented 10 subjects with a matrix of more than 650 lines leaning at a 45-degree angle, like slashes, with one object somewhere in the array reversed, like a backslash. The participants had to determine within seconds whether “the odd one out” resided on the left- or right-hand side of the screen in front of them. The subjects chose most accurately when they had little to no time to scrutinize the matrix.