A large body of work has implicated the ventral striatum (VS) in aspects of reinforcement learning (RL). However, less work has directly examined the effects of lesions in the VS, or other forms of inactivation, on 2-armed bandit RL tasks. We have recently found that lesions in the VS in macaque monkeys affect learning with stochastic schedules but have minimal effects with deterministic schedules. The reasons for this are not currently clear. Because our previous work used short intertrial intervals, one possibility is that the animals were using working memory to bridge stimulus-reward associations from 1 trial to the next. In the present study, we examined learning of 60 pairs of objects, in which the animals received only 1 trial per day with each pair. The large number of object pairs and the long interval (approximately 24 hr) between trials with a given pair minimized the chances that the animals could use working memory to bridge trials. We found that monkeys with VS lesions were unimpaired relative to controls, which suggests that animals with VS lesions can still learn to select rewarded objects even when they cannot make use of working memory. (PsycINFO Database Record

中文翻译：

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腹侧纹状体病变在缓慢的时间尺度上不影响确定性结果的强化学习。

大量工作牵涉到强化学习（RL）方面的腹侧纹状体（VS）。但是，较少的工作直接检查了VS中的病变或其他灭活形式对2臂土匪RL任务的影响。我们最近发现，猕猴VS中的病变会影响随机时间表的学习，但对确定性时间表的影响很小。目前尚不清楚其原因。因为我们之前的工作使用的是较短的间隔时间，所以一种可能性是动物正在使用工作记忆来将刺激-奖励关联从一项试验过渡到下一项试验。在本研究中，我们检查了60对物体的学习情况，其中每天每对动物仅接受1次试验。大量的对象对以及给定对之间的两次试验之间的间隔时间较长（约24小时），使动物可以利用工作记忆桥接试验的机会降到最低。我们发现，具有VS病变的猴子相对于对照组没有受到损害，这表明具有VS病变的动物即使不能利用工作记忆，仍然可以学习选择奖励对象。（PsycINFO数据库记录