Takahashi Yuji K, Stalnaker Thomas A, Roesch Matthew R, Schoenbaum Geoffrey
Intramural Research Program, National Institute on Drug Abuse.
Department of Psychology, University of Maryland, College Park.
Behav Neurosci. 2017 Apr;131(2):127-134. doi: 10.1037/bne0000192.
Dopaminergic reward prediction errors in monkeys reflect inferential reward predictions that well-trained animals can make when associative rules change. Here, in a new analysis of previously described data, we test whether dopaminergic error signals in rats are influenced by inferential predictions and whether such effects depend on the orbitofrontal cortex (OFC). Dopamine neurons were recorded from controls or rats with ipsilateral OFC lesions during performance of a choice task in which odor cues signaled the availability of sucrose reward in 2 wells. To induce prediction errors, we manipulated either the timing or number of rewards delivered in each well across blocks of trials. Of importance, a change in reward at 1 well predicted a change in reward at the other on later trials. We compared behavior and neural activity on trials when such inference was possible versus trials involving the same reward change when inference was not possible. Rats responded faster when they could infer an increase in reward compared to when the same reward was coming but they could not infer a change. This inferential prediction was reflected in the firing of dopamine neurons in controls, which changed less to unexpected delivery (or omission) of reward and more to the new high-value cue on inference versus noninference trials. These effects were absent in dopamine neurons recorded in rats with ipsilateral OFC lesions. Thus, dopaminergic error signals recorded in rats are influenced by both experiential and inferential reward predictions, and the effects of inferential predictions depend on OFC. (PsycINFO Database Record
猴子体内的多巴胺能奖赏预测误差反映了训练有素的动物在联想规则改变时能够做出的推理奖赏预测。在此，我们对先前描述的数据进行了一项新分析，以测试大鼠体内的多巴胺能误差信号是否受推理预测的影响，以及此类影响是否依赖于眶额皮质（OFC）。在一项选择任务的执行过程中，从对照组或同侧OFC损伤的大鼠记录多巴胺神经元活动，在该任务中，气味线索表明两个孔中蔗糖奖赏的可得性。为了诱导预测误差，我们在各试验组中操纵每个孔中给予奖赏的时间或数量。重要的是，一个孔中奖赏的变化预示着后续试验中另一个孔中奖赏的变化。我们比较了在可能进行此类推理的试验与涉及相同奖赏变化但无法进行推理的试验中的行为和神经活动。与相同奖赏即将到来但无法推断变化的情况相比，当大鼠能够推断奖赏增加时，它们的反应更快。这种推理预测反映在对照组多巴胺神经元的放电中，在推理试验与非推理试验中，多巴胺神经元对意外给予（或遗漏）奖赏的反应变化较小，而对新的高价值线索的反应变化较大。在同侧OFC损伤的大鼠中记录的多巴胺神经元中未出现这些效应。因此，在大鼠中记录的多巴胺能误差信号受经验性和推理性奖赏预测的影响，且推理预测的影响依赖于OFC。（《心理学文摘数据库记录》 ）
