Figure 1.

Design of the RDT. A, Each block consists of 8 forced choice trials and 20 free choice trials. Each free choice trial consists of a deliberation and outcome phase. Rats must nosepoke for the extension of either one lever (forced choice trial) or both levers (free choice trial). A press on one lever yields a small safe reward, and a press on the other yields a large reward accompanied by variable probabilities of footshock punishment. B, Laser delivery occurred at 1 of 5 possible phases during each free choice trial (with laser delivery during each test session taking place in only 1 of the 5 phases). Green bars represent periods of laser delivery.