Figure 2.

Baseline performance of the slot machine task. On win trials, when all three lights had set to on ((1,1,1)), animals chose the collect lever 100% of the time (a, b). As the number of lights illuminated decreased, so did the preference for the collect lever (a). Animals consistently showed a strong preference for the collect lever on 2-light losses, or near-miss trials. The proportion of collect responses made on both 2-light and 1-light losses also varied according to the precise pattern of lights illuminated (b). In the first week of training, rats were slower to respond in the subsequent hole if the previous hole had set to off (c). However, this differential effect was no longer observed once stable choice behaviour has been established. This pattern was observed for both the middle and last holes, therefore, the graph reflects the combined data from both holes. All data shown are the mean across five sessions±SEM.