A computer touch-screen apparatus for training visual discriminations in rats

We describe an operant conditioning apparatus that uses computerized touch-screen technology and is designed for the versatile and highly controlled testing of rats in a potentially wide variety of behavioral paradigms. Although computer-controlled touch-screen systems have been developed for use with pigeons, monkeys, and humans, analogous technologies and methods have not yet been developed for rats. The development of a touch-screen system for rats could enhance the efficiency of behavioral research with rats, and may offer a unique tool for studying animal learning. In the first test of the utility of the apparatus, 3 Sprague-Dawley rats learned to activate the touch screen only after the touch-screen panel was made slightly movable. These animals then learned to discriminate visual stimuli presented on the computer monitor, but only after the food magazine and pellet dispenser were moved to the rear of the chamber opposite the stimulus display and response window. In a test of the utility of the modified apparatus, 6 Long-Evans rats learned to activate the touch screen and learned one of three different simple discriminations using computer-generated, visually presented stimuli. A basic method for training rats to activate the computer touch screen and for visual discrimination training is described. Results show that rats learned to activate the touch screen and discriminate visual stimuli presented on a computer monitor. Potential applications and advantages of the touch-screen-equipped rat operant conditioning chamber are discussed.