Plane Facts on Geometry

The brain apparently uses simple geometric calculations to instantly figure out depth and distances, but researchers say they do not know if the ability is learned or inherited.

Scientists at the Smith-Kettlewell Eye Research Institute in San Francisco who are studying how the nervous system enables people to see in three dimensions have found that the brain uses either innate or learned geometric principles.

Kenneth Nakayama, Gerald Silverman and Shisuke Shimojo wrote in the current issue of the British scientific journal Nature that the geometrical calculations needed to work out depth and distance of an object are carried out in a rapid sequence of mathematical events stored in the brain.

Nakayama, a neurobiologist, and his team drew their conclusion after a series of experiments in which people were asked to view objects through a stereoscope moving from right to left and then from left to right.