Biological Motion Detection in Rats

Abstract

This study will examine the rodent visual system by assessing whether they can discriminate between various biological motion point‐light displays. Pilot data suggests that rats can discriminate between a human walker point‐light display walking left and right. Therefore this study will investigate which kind of information rats use to differentiate biological motion; the overall shape of the moving body (conformational theory) versus the local movement of the feet (ballistic motion theory). First, we will train the rats to discriminate between human point‐light displays walking in opposite directions using a modified Morris water maze. Then we will observe their reactions to a backwards‐walking display. If the rats use shape as a visual cue for biological motion, they will swim towards the goal arm that corresponds to the direction the backwards walker is facing. However, if the rats use ballistic motion as a visual cue for biological motion, they will swim towards the goal arm that corresponds to the direction the backwards walker is moving. We hypothesize that rats use the ballistic motion of the feet as a cue for life detection. This is the first study to investigate whether rats can detect biological motion, and will contribute to the theory that animals have evolved an innate ability to quickly detect biological motion of vital importance.