Figure 2.

Mice preferentially reduce the intertrial variability of reward-related kinematic parameters. a, In the velocity task, a trial was rewarded if the average velocity of the lever (to its maximum position) was between 50 and 100°/s. Mice initiated a trial by pulling the lever past the threshold range (0°-6°, shown in gray) and were required to return the lever to the start position within 2 s. b, WT mice (n = 16) improved their performance of the task over 1 week (p < 0.0001). c, The proportion of rewarded trials did not increase significantly past day 7 of testing in WT mice (n = 16). d, The Fano factor of pull amplitude calculated for each day of testing increased significantly over 1 week (p = 0.04) in WT mice (n = 16). e, The Fano factor of peak velocity calculated for each day of testing decreased significantly over 1 week (p = 0.005) in WT mice (n = 16). All data are from mice tested on the velocity task and are presented as mean ± SEM.