National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-4415, USA.
Neuron. 2012 Jun 7;74(5):947-60. doi: 10.1016/j.neuron.2012.03.037.
The role that frontal-striatal circuits play in normal behavior remains unclear. Two of the leading hypotheses suggest that these circuits are important for action selection or reinforcement learning. To examine these hypotheses, we carried out an experiment in which monkeys had to select actions in two different task conditions. In the first (random) condition, actions were selected on the basis of perceptual inference. In the second (fixed) condition, the animals used reinforcement from previous trials to select actions. Examination of neural activity showed that the representation of the selected action was stronger in lateral prefrontal cortex (lPFC), and occurred earlier in the lPFC than it did in the dorsal striatum (dSTR). In contrast to this, the representation of action values, in both the random and fixed conditions, was stronger in the dSTR. Thus, the dSTR contains an enriched representation of action value, but it followed frontal cortex in action selection.
额-纹状体回路在正常行为中的作用尚不清楚。两个主要的假设表明，这些回路对于动作选择或强化学习很重要。为了检验这些假设，我们进行了一项实验，猴子必须在两种不同的任务条件下选择动作。在第一种（随机）条件下，动作是基于感知推断选择的。在第二种（固定）条件下，动物使用来自前一个试验的强化来选择动作。对神经活动的检测表明，所选动作的表示在外侧前额叶皮层（lPFC）中更强，并且在 dSTR 中比在 dSTR 中更早出现。相比之下，在随机和固定条件下，动作值的表示在 dSTR 中更强。因此，dSTR 包含一个丰富的动作值表示，但它在动作选择中紧随额叶皮层。
