Figure 1.

Long-term motor learning in the two-direction joystick task. A, Behavioral task setup. A head-fixed mouse grabs the joystick with its left paw and makes forelimb reaches in the forward and downward directions. B, Two-direction joystick task rule. Each trial begins with either forward or downward drifting gratings on the monitor, and the mouse must press the joystick in the same direction as the visual stimulus after an auditory tone to receive a reward. C, Learning curve for the fraction of correct choices. Data are mean ± SE (n = 22 mice). The average fraction of correct choices in the first 11 training sessions was compared with the average fraction in the last 11 training sessions across 22 mice (paired bootstrap test; Table 1; see Materials and Methods). D, Learning curve for the target acquisition time (i.e., duration between movement onset and target entry). The same illustration format and statistical test as in C. E, Example rewarded movements in early versus late training sessions (1 session/day). Green and purple traces represent forward and downward movements, respectively. Fifteen movements were randomly selected in each direction in each session. F, Learning curve for movement consistency (i.e., the average trial-to-trial correlation coefficient between pairs of movement trajectories from rewarded trials in the same direction). The higher the correlation is, the more consistent the trajectories across trials are. The same illustration format and statistical test as in C.