A microcomputer-based activity meter for multiple animals

We describe and validate a computer-video system that records and displays in real-time the activity of multiple specimens in a user-defined space, at user-defined intervals. The computer program uses image subtraction algorithms to record changes in video images, and stores observations in column format or as a series of 2-D matrices. The program was tested under various lighting conditions, backgrounds, specimen size and specimen speed. An AV model of Macintosh computer with video input from a camera or video cassette recorder was used to record and analyze the mechanical movement of spots on a turntable and the locomotor activity of an ant colony. The limitations and potential applications of the program are discussed.