Figure 1. Two-interval timing task in mice.
(A) Task schematic. In each trial mice were presented with one of two olfactory cues for 0.2 s, and rewarded if they withheld licking during the time period indicated in red. Mice were rewarded irrespective of whether they licked or not during the acceptance period shown in grey. Cue 1: short interval, Cue 2: long interval.
(B) Learning curve of mean lick onset time for all 8 mice up to the day before recording day (1 session per day). The dashed horizontal lines denote the start of the lick acceptance period for short (blue) and long interval (green) trials.
(C) Lick raster plot on short (top) and long (middle) interval trials for one animal on the recording day. Only trials with anticipatory licking are shown (Cyan lines denote the time of reward). Bottom: distribution of the same animal’s lick onset times on short (blue) and long (green) interval trials.
(D) Average lick rate on short (blue) and long (green) interval trials across all mice (n = 8). Shaded area represents SEM. Cyan lines denote the time of reward.
(E) The mean lick onset time was significantly higher for the long interval (n = 8 mice; two-sided paired t-test, t7 = 8.296, P < 0.0001).
(F) The standard deviation of the lick onset time was significantly higher for the long interval (n = 8 mice; two-sided paired t-test, t7 = 6.728, P = 0.0003).