Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Nat Commun. 2018 Jul 3;9(1):2596. doi: 10.1038/s41467-018-05012-y.
The posterior parietal cortex (PPC) has been implicated in perceptual decisions, but whether its role is specific to sensory processing or sensorimotor transformation is not well understood. Here, we trained mice to perform a go/no-go visual discrimination task and imaged the activity of neurons in primary visual cortex (V1) and PPC during engaged behavior and passive viewing. Unlike V1 neurons, which respond robustly to stimuli in both conditions, most PPC neurons respond exclusively during task engagement. To test whether signals in PPC primarily encoded the stimulus or the animal's impending choice, we image the same neurons before and after re-training mice with a reversed sensorimotor contingency. Unlike V1 neurons, most PPC neurons reflect the animal's choice of the new target stimulus after re-training. Mouse PPC is therefore strongly task-dependent, reflects choice more than stimulus, and may play a role in the transformation of visual inputs into motor commands.
后顶叶皮层（PPC）已被牵涉到知觉决策中，但它的作用是专门针对感觉处理还是感觉运动转换尚不清楚。在这里，我们训练老鼠执行一个 Go/No-Go 视觉辨别任务，并在参与行为和被动观察期间对初级视觉皮层（V1）和 PPC 的神经元活动进行成像。与在两种条件下都对刺激产生强烈反应的 V1 神经元不同，大多数 PPC 神经元仅在任务参与期间作出反应。为了测试 PPC 中的信号主要编码刺激还是动物即将做出的选择，我们在重新训练老鼠以反转感觉运动关联后，对相同的神经元进行成像。与 V1 神经元不同，大多数 PPC 神经元在重新训练后反映了动物对新目标刺激的选择。因此，老鼠的 PPC 强烈依赖于任务，对选择的反应大于对刺激的反应，并且可能在将视觉输入转换为运动命令中发挥作用。
