Posterior parietal cortex represents sensory history and mediates its effects on behaviour
Posterior parietal cortex represents sensory history and mediates its effects on behaviour
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DOI：
10.1038/nature25510
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发表时间：
2018-02-15
期刊：
影响因子：
64.8
通讯作者：
Brody, Carlos D.
中科院分区：
文献类型：
--
作者：
Akrami, Athena;Kopec, Charles D.;Brody, Carlos D.
许多认知和神经计算模型都假定使用和估计先前的刺激统计数据（1-4）：人们早就知道，工作记忆和知觉受到先前感觉经验的强烈影响，即使感觉历史与当前手头的任务无关。然而，对于计算和使用这种先验经验所必需的神经机制和大脑区域是未知的。在这里，我们报告了后顶叶皮层（PPC）是表征和使用先前刺激信息的关键位点。我们在听觉参数工作记忆任务中训练大鼠，发现它们表现出大量且易于量化的感觉刺激历史行为效应，类似于在人类（5,6）和猴子(7)中观察到的结果。先前关于PPC支持工作记忆的建议（8,9）预测该区域的光遗传沉默将损害我们工作记忆任务中的行为。与此预测相反，我们发现沉默PPC显着提高了性能。对行为的定量分析表明，这种改善是由于选择性地减少了先前感官刺激的影响。电生理记录显示，PPC神经元携带的有关先前试验的感觉刺激的信息远远多于当前试验的刺激信息。此外，对于给定的大鼠，关于前试验感觉历史的PPC神经放电率的信息越多，感觉历史的行为效应就越大，这表明行为与刺激历史的PPC表征之间存在紧密联系。我们的研究结果表明，PPC是处理感觉刺激历史的核心组成部分，并且可以进一步研究关于感知和工作记忆如何受到先前感觉信息影响的长期问题。
Many models of cognition and of neural computations posit the use and estimation of prior stimulus statistics(1-4): it has long been known that working memory and perception are strongly impacted by previous sensory experience, even when that sensory history is not relevant to the current task at hand. Nevertheless, the neural mechanisms and regions of the brain that are necessary for computing and using such prior experience are unknown. Here we report that the posterior parietal cortex (PPC) is a critical locus for the representation and use of prior stimulus information. We trained rats in an auditory parametric working memory task, and found that they displayed substantial and readily quantifiable behavioural effects of sensory-stimulus history, similar to those observed in humans(5,6) and monkeys(7). Earlier proposals that the PPC supports working memory(8,9) predict that optogenetic silencing of this region would impair behaviour in our working memory task. Contrary to this prediction, we found that silencing the PPC significantly improved performance. Quantitative analyses of behaviour revealed that this improvement was due to the selective reduction of the effects of prior sensory stimuli. Electrophysiological recordings showed that PPC neurons carried far more information about the sensory stimuli of previous trials than about the stimuli of the current trial. Furthermore, for a given rat, the more information about previous trial sensory history in the neural firing rates of the PPC, the greater the behavioural effect of sensory history, suggesting a tight link between behaviour and PPC representations of stimulus history. Our results indicate that the PPC is a central component in the processing of sensory-stimulus history, and could enable further neurobiological investigation of long-standing questions regarding how perception and working memory are affected by prior sensory information.