Neural basis of proximal influences on choice: recent reinforcement, inter-trial interval, and uncertainty

Describing how animals make decisions is fundamental to understanding animal behaviour. Here we describe the transient yet significant influence of recent wins and losses on subsequent decisions in a competitive two-choice paradigm. We report that the drive to shift to alternate choices after a loss (lose-shift response) decays monotonically within the first few seconds of the inter-trial interval whereas the tendency to repeat a choice after a win (win-stay response) is initially low, gradually increases for few seconds, and then declines. We also show that the level of contextual uncertainty is correlated with the number of exploratory responses observed in the operant chamber. Furthermore, we report that lose-shift is dependent on the integrity of the ventrolateral striatum whereas win-stay is dependent on proper phasic dopaminergic signalling in the ventromedial striatum. Overall, our results suggest that lose-shift and win-stay response depend on dissociable circuits within the ventral striatum