THE organisation of lines and edges inherent in the shapes of trees, flowers, rocks and other natural objects has left its imprint on the mammalian brain. So much so that connections between nerve cells in the visual cortex appear to be tuned to recognise such features.
Ha Youn Lee and Mehran Kardar of the Massachusetts Institute of Technology analysed the images of natural objects by breaking them down mathematically into collections of lines with distinct orientations. What they found was that for any set of parallel lines, the density of the lines varied more in a direction perpendicular to the…
