Sham Kakade, Peter Dayan
Substantial data support a temporal difference (TO) model of dopamine (OA) neuron activity in which the cells provide a global error signal for reinforcement learning. However, in certain cir(cid:173) cumstances, OA activity seems anomalous under the TO model, responding to non-rewarding stimuli. We address these anoma(cid:173) lies by suggesting that OA cells multiplex information about re(cid:173) ward bonuses, including Sutton's exploration bonuses and Ng et al's non-distorting shaping bonuses. We interpret this additional role for OA in terms of the unconditional attentional and psy(cid:173) chomotor effects of dopamine, having the computational role of guiding exploration.