Posterior Parietal Cortex Persistent Activity and Working Memory

人类能够在短时间内同时存储的东西（我们的工作记忆）非常少。最大值被认为是7，就像电话号码中的数字一样，但平均值只有4！我们工作记忆的有限容量取决于分布在我们大脑额叶和顶叶的神经机制，但我们目前的知识状态还远未完成。一方面，由于没有足够的动物模型来研究工作记忆容量，因此只研究了基本的记忆机制。另一方面，尽管所有的证据都表明顶叶皮层也起着重要作用，但我们对这些基本记忆机制的了解几乎都是从对额叶皮层的研究中获得的。

The number of things that humans can hold simultaneously in memory for a short time (our working memory) is remarkably small. The maximum is thought to be seven, as in the number of digits in a phone number, but the average is about only four! The limited capacity of our working memory depends on neural mechanisms that are distributed in the frontal and parietal lobes of our brain, but the current state of our knowledge is far from complete. On the one hand, only basic memory mechanisms have been studied because there exists no adequate animal model to study working memory capacity. On the other hand, nearly all our knowledge about these basic memory mechanisms has been obtained from studies of the frontal cortex despite all the evidence indicating that the parietal cortex also plays an important role.