Morris Genela, Nevet Alon, Arkadir David, Vaadia Eilon, Bergman Hagai
Interdisciplinary Center for Neural Computation (ICNC), Hebrew University, Jerusalem, Israel.
Nat Neurosci. 2006 Aug;9(8):1057-63. doi: 10.1038/nn1743. Epub 2006 Jul 23.
Current models of the basal ganglia and dopamine neurons emphasize their role in reinforcement learning. However, the role of dopamine neurons in decision making is still unclear. We recorded from dopamine neurons in monkeys engaged in two types of trial: reference trials in an instructed-choice task and decision trials in a two-armed bandit decision task. We show that the activity of dopamine neurons in the decision setting is modulated according to the value of the upcoming action. Moreover, analysis of the probability matching strategy in the decision trials revealed that the dopamine population activity and not the reward during reference trials determines choice behavior. Because dopamine neurons do not have spatial or motor properties, we conclude that immediate decisions are likely to be generated elsewhere and conveyed to the dopamine neurons, which play a role in shaping long-term decision policy through dynamic modulation of the efficacy of basal ganglia synapses.
目前关于基底神经节和多巴胺能神经元的模型强调它们在强化学习中的作用。然而，多巴胺能神经元在决策中的作用仍不明确。我们记录了参与两种试验的猴子体内多巴胺能神经元的活动：指令选择任务中的参考试验和双臂赌博机决策任务中的决策试验。我们发现，在决策环境中，多巴胺能神经元的活动根据即将执行动作的价值进行调节。此外，对决策试验中概率匹配策略的分析表明，是多巴胺能神经元群体活动而非参考试验中的奖励决定了选择行为。由于多巴胺能神经元不具备空间或运动特性'，我们得出结论，即时决策可能在其他地方产生并传递给多巴胺能神经元，而多巴胺能神经元通过动态调节基底神经节突触的效能，在塑造长期决策策略中发挥作用。
