Scientists at Newcastle University have discovered neurons in insect brains that compute 3D distance and direction. Understanding these could help vision in robots. In a specially-designed insect cinema, the mantises were fitted with 3D glasses and shown 3D movies of simulated bugs while their brain activity was monitored. When the image of the bug came into striking range for a predatory attack, scientists were able to record the activity of individual neurons. Praying mantises use 3D perception, scientifically known as stereopsis, for hunting.
By using the disparity between the two retinas they are able to compute distances and trigger a strike of their forelegs when prey is within reach. The neurons recorded were stained, revealing their shape which allowed the team to identify four classes of neuron likely to be involved in mantis stereopsis. The images captured using a powerful microscope show the dendritic tree of a nerve cell – where the nerve cell receives inputs from the rest of the brain – believed to enable this behaviour. Researchers hope mantises can help us develop simpler algorithms for machine vision.