Figure 1 .

Fixed-interval timing tasks and recording locations. (A) On Day 0, rodents performed fixed-interval timing tasks in which a reward was given for the first lever press after a 12-s interval (FI12). Interval start was cued by a house light, motivation was a liquid reward, and presses before interval end were not reinforced. On Day 1, there was a new temporal context with the addition of a second, shorter 3-s interval (FI3) cued by a distinct light. FI3 trials were randomly intermixed with FI12 trials. Recordings were performed for 3 days of two-interval performance (Days 1–3). (B) Animals were implanted with multielectrode recording arrays targeting the MFC and DMS; horizontal sections with approximate AP coordinates shown. (C) MSNs within the DMS were identified based on waveform shape.