Limits on the memory storage capacity of bounded synapses
Limits on the memory storage capacity of bounded synapses
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DOI：
10.1038/nn1859
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发表时间：
2007-04-01
影响因子：
25
通讯作者：
Abbott, L. F.
中科院分区：
文献类型：
--
作者：
Fusi, Stefano;Abbott, L. F.
以突触连接模式维持的记忆被与新记忆存储相关的持续可塑性迅速覆盖和破坏。记忆寿命短源于任何现实模型中必须对突触效能施加的限制。我们探索了是否可以通过允许突触在到达边界之前遍历大量状态，或者通过改变这些边界施加的方式来提高记忆性能。在硬边界的情况下，记忆寿命与突触状态数量的平方成正比，但前提是增强和抑制精确平衡。不需要通过施加软边界进行微调就可以获得性能的改进，但是这种改进仅与突触状态的数量呈线性关系。我们探索了其他几种可能性，并得出结论，提高记忆性能需要对记忆存储的标准模型进行更彻底的修改。
Memories maintained in patterns of synaptic connectivity are rapidly overwritten and destroyed by ongoing plasticity related to the storage of new memories. Short memory lifetimes arise from the bounds that must be imposed on synaptic efficacy in any realistic model. We explored whether memory performance can be improved by allowing synapses to traverse a large number of states before reaching their bounds, or by changing the way these bounds are imposed. In the case of hard bounds, memory lifetimes grow proportional to the square of the number of synaptic states, but only if potentiation and depression are precisely balanced. Improved performance can be obtained without fine tuning by imposing soft bounds, but this improvement is only linear with respect to the number of synaptic states. We explored several other possibilities and conclude that improving memory performance requires a more radical modification of the standard model of memory storage.