Temporal Discrimination

A different cohort of mice underwent training on a temporal discrimination task [⁴⁴]. Following initial dipper training, mice received FR1 lever training, in which a reward was given immediately following a lever press that occurred within the first 30 s of lever presentation or if no press was made for 30 s. In both cases, the lever retracted upon dipper presentation. Trials occurred on a variable ITI ( mean = 45 s). These FR1/FT30 sessions lasted until mice earned 30 rewards in 2 consecutive sessions. For discrimination training, mice learned to press one of the two levers after a 2-s tone (“short”) and the other following an 8-s tone (“long”) to earn a reward. The first two days of training involved presenting only one sample duration and its corresponding lever, followed by two days where half the trials were short-tone and half long-tone with single lever presentations. For the next 3 days, 50% of the trials presented either sample durations followed by extension of both levers (choice response trials), while the other 50% of trials presented a single lever associated with the correct categorization of the sample duration (forced response trials). Mice were then trained on a 75% choice response session for 3 days, followed by 15 100% choice response sessions. The durations of the short and long tones were increased from 2 to 6 s and from 8 to 24 s and original lever assignments were maintained. Sixteen additional sessions of this type were conducted.