The Neural Representation of Reward in Working Memory

描述（由申请人提供）：虽然我们对简单奖励导向行为（如条件反射）的神经机制了解很多，但我们对奖励信息如何与执行过程（如工作记忆）相互作用知之甚少。这项研究的目的是研究不同的奖励是如何在工作记忆中保存的，比较然后选择，以允许有效，灵活的行为。猴子将被训练从两个顺序呈现的奖励中选择一个，两个奖励之间有短暂的延迟。因此，猴子必须在工作记忆中保留第一个奖励，直到第二个奖励出现，此时它比较两个奖励并选择一个。我们将记录猴子执行这项任务时前额叶皮层（RFC）单个神经元的活动。我们将研究RFC神经元是否在延迟期间保持关于奖励的信息（指示工作记忆过程），以及这种编码是否相对抽象和灵活，这将有助于评估广泛不同的奖励和目标。我们将研究两种奖励的比较和选择背后的神经过程，这些过程是决策的重要组成部分。我们还将比较初级和次级记忆是如何在工作记忆中保持的。RFC的功能障碍，特别是眶额区，与药物成瘾有关。如果不能使用工作记忆来表征替代性奖励和目标（比如戒烟），成瘾者就无法对成瘾行为进行自上而下的控制，从而可能会加剧成瘾。因此，了解决定如何在不同奖励之间做出选择和优先级的神经机制可能会让我们更清楚地了解成瘾的病理学，并提供旨在增强自上而下控制和减少康复成瘾者复发可能性的替代治疗策略

DESCRIPTION (provided by applicant): While we know much about the neuronal mechanisms that underlie simple reward-directed behaviors, such as conditioning, we know very little about how reward information interacts with executive processes such as working memory. The aim of this grant is to examine how different rewards are held in working memory, compared and then selected, in order to allow efficient, flexible behavior. Monkeys will be trained to choose one of two sequentially presented rewards, separated by a brief delay. Thus, the monkey has to hold the first reward in working memory until the second reward is presented, at which point it compares the two rewards and selects one for its choice. We will record the activity of single neurons in the prefrontal cortex (RFC) while the monkey is performing this task. We will examine whether RFC neurons maintain information about the reward during the delay (indicative of working memory processes), and whether this encoding is relatively abstract and flexible which would facilitate the evaluation of widely disparate rewards and goals. We will investigate the neuronal processes that underlie the comparison and selection of the two rewards, processes which are important components of decision-making. We will also compare how primary and secondary reinforcers are held in working memory. Dysfunction of the RFC, particularly the orbitofrontal region, has been implicated in drug addiction. A failure to use working memory representations of alternate rewards and goals (such as quitting the drug) might exacerbate addiction by preventing the addict from exerting top-down control over addictive behavior. Thus, understanding the neuronal mechanisms that determine how choices and priorities are made between different rewards may provide us with a clearer understanding of the pathology of addiction, and with alternative therapeutic strategies aimed at boosting top-down control and attenuating the likelihood of relapse in the recovering addict