Extended Data Fig. 2: Detailed timing of behavioral events in recording and optogenetic sessions.

a, A light in the center port indicates that rats should nose poke there to initiate a trial and keep their noses there until the center light offset (‘‘fixation’’ period). During the first 1 s of the fixation period, a Pro or Anti sound is played to indicate the current task, followed by a 500-ms silent delay. The center light is then turned off, indicating that the animal is now free to withdraw from the center port, and the moment it withdraws, a left or right light is turned on to indicate the target location. The temporal gap between fixation offset (that is, end of the delay period) and target stimulus onset was controlled by animals and was thus variable on each trial (mean = 127 ms after fixation offset). Reaction Time (RT) is defined as the time from target onset until side poke. The 3 vertical lines correspond to the vertical lines in Fig. 1–3. b, Similar to a, for optogenetic sessions. To ensure that all sub-trial optogenetic inactivation conditions have the same laser duration (750 ms, green shade), rats were trained on a modified version of the behavior where the task cue period and the delay period both lasted 750 ms. Choice period inactivation started at the onset of visual target and lasted 750 ms, covering the time it took animals to form and execute the orienting choice into the side poke (690.8 ± 39.1 ms, mean ± s.e.m. across animals’ median RT in optogenetic inactivation sessions).