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Table 1 Testing schedule for probabilistic choice task. Subjects were trained and tested according to the schedule shown here. Initial pre- and postoperative testing was conducted with the probability of large reinforcer delivery declining across trial blocks from 1 to 0.0625 (the steps were p = 1, 0.5, 0.25, 0.125, and 0.0625). Subsequently, subjects were tested alternating between the hungry and sated state (as described in the Methods), before the reinforcement probabilities were manipulated further, as indicated.

From: Effects of lesions of the nucleus accumbens core on choice between small certain rewards and large uncertain rewards in rats

Sessions Description Probability (small reward of 1 pellet) Probability (large reward of 4 pellets)
1–12 Preoperative training (12 sessions) p = 1 p = 1 to 0.0625, decreasing
- Surgery and recovery - -
13–24 Postoperative baseline testing (12 sessions) p = 1 p = 1 to 0.0625, decreasing
25–28 Satiety tests (4 sessions) p = 1 p = 1 to 0.0625, decreasing
29–34 Equal probabilities, certain (6 sessions) p = 1 p = 1
35–46 Increasing probabilities (12 sessions) p = 1 p = 0.0625 to 1, increasing
47–52 Large reinforcer always very unlikely (6 sessions) p = 1 p = 0.0625