An improved Morris water maze tracking algorithm for psychophysical studies.

We have developed an algorithm to track a rat swimming in a Morris Water Maze. It provides an update on rodent position 15 times per second. The tracking algorithm uses a rotation insensitive tracking template coupled with a limited exhaustive search technique to maintain lock on the moving rat. At the completion of the run, the relative time the rat spent in each quadrant is reported. The tracking algorithm was successfully used to evaluate the time course of memory loss and correlate that to tissue loss in the rat cortex following blunt trauma to the sensory cortex. Results of that study are reported in another paper. Our project budget did not allow for commercially available software to perform the tracking task which typically provide position updates 10 times per second. This paper focuses on the tracking algorithm and support equipment used to measure the rats' progress in the maze.