The methods we previously described for training freely behaving rats in visual tasks (see Meier et al 2011) can also be used to train mice. Details of methods for mice, and evidence that orientation discrimination is V1-dependent in this task mice, are available in THIS PREPRINT, "A Sparse Unreliable Distributed Code Underlies the Limits of Behavioral Discrimination" by Balaji Sriram, Alberto Cruz-Martin, Lillian Li, Pamela Reinagel, Anirvan Ghosh.

Mice are trained in visual discrimination in an automated operant conditioning chamber. (A) Schematic of trial structure performed by the subject. Subjects request trials during the Request phase (Req.) by licking the request port (center). Upon trial request, a visual stimulus is presented on the screen and the system waits for animal response (response phase; Resp.) The system then reinforces subject response in the reinforcement phase (Reinf.) by either providing water rewards (~10 ul) for correct responses or timeouts (5-20 s) for incorrect responses during which subjects cannot do any further trials. After the reinforcement phase, the system automatically returns to the request phase for the next trial. (B) Moving average of performance (black) of an example mouse through multiple steps (colored trial blocks) during the course of the experiment. Mice initially perform a go-towards-luminance task (blue). After reaching threshold performance, they are trained on a go-towards-orientation task (blue-green). After reaching threshold performance on this task, mice move into a series of modifications of the go-towardsorientation task where we varied various features of the stimulus(varied contrast, green; varied spatial frequency, orange; varied orientation, yellow) one at a time keeping all the others constant.