Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity.
Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity.
复制标题
基本限制了作为持续活动的持续记忆的持久性和能力。
DOI：
10.7554/elife.22225
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发表时间：
2017-09-07
期刊：
影响因子：
7.7
通讯作者：
Fiete IR
中科院分区：
文献类型：
--
作者：
Koyluoglu OO;Pertzov Y;Manohar S;Husain M;Fiete IR
人们普遍认为，持续的神经活动是短期记忆的基础。然而，正如我们所展示的，直接存储在这样的网络中的信息的退化表现与人类的短期记忆表现不同。我们构建了一个更一般的框架，其中记忆被视为通过噪声通道传递信息的问题，其退化特征类似于持续活动网络的退化特征。如果大脑在将信息传递到这样的网络之前，首先对信息进行适当的编码，那么信息可以被更忠实地存储。在这个框架下，我们得到了召回准确率的一个基本下界，它随着存储时间和存储物品的数量而下降。我们发现，人类的表现，尽管与持续活动网络中直接(未编码)存储的模型不一致，但可以很好地符合理论界限。这一发现与一种观点是一致的，即如果大脑以持续活动的模式存储信息，它可能会使用将噪音影响降至最低的代码，从而激励人们在大脑中寻找这样的代码。
It is widely believed that persistent neural activity underlies short-term memory. Yet, as we show, the degradation of information stored directly in such networks behaves differently from human short-term memory performance. We build a more general framework where memory is viewed as a problem of passing information through noisy channels whose degradation characteristics resemble those of persistent activity networks. If the brain first encoded the information appropriately before passing the information into such networks, the information can be stored substantially more faithfully. Within this framework, we derive a fundamental lower-bound on recall precision, which declines with storage duration and number of stored items. We show that human performance, though inconsistent with models involving direct (uncoded) storage in persistent activity networks, can be well-fit by the theoretical bound. This finding is consistent with the view that if the brain stores information in patterns of persistent activity, it might use codes that minimize the effects of noise, motivating the search for such codes in the brain.