Effective visual working memory capacity: an emergent effect from the neural dynamics in an attractor network.
Effective visual working memory capacity: an emergent effect from the neural dynamics in an attractor network.
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DOI：
10.1371/journal.pone.0042719
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Deco G
中科院分区：
文献类型：
--
作者：
Dempere-Marco L;Melcher DP;Deco G
由于工作记忆是一般认知功能的基础，因此对工作记忆容量的研究在认知心理学中占有极其重要的地位。虽然对工作记忆容量的限制已经进行了深入的研究，但它的起源仍然是一个激烈争论的问题。直到最近，视觉显著性在调节工作记忆存储容量中的作用才被实验评估，并被证明为工作记忆功能提供了有价值的见解。在计算领域，吸引子网络已经成功地解释了许多工作记忆任务中的心理物理和神经生理数据，因为它们能够在延迟期间产生持续升高的放电率。在这里，我们通过一个具有脉冲神经元的生物物理现实吸引子网络来研究工作记忆容量的机制，同时考虑到最近的两个实验观察结果：1)视觉显著项目的存在减少了工作记忆中可以保留的项目数量；2)视觉显著项目通常以不保留尽可能多的非显著项目为代价保留在记忆中。我们的模型表明，工作记忆容量是由两个基本过程决定的：将视觉项目编码到工作记忆中，并在编码后的项目从视觉显示中移除后对其进行维护。虽然维持主要取决于侧向抑制对助记活动的限制，但编码受到受刺激的神经组合达到足够高水平兴奋的能力的限制，这一过程受神经元池之间竞争和合作的动态控制。因此，编码取决于视觉工作记忆任务，这使我们引入了有效工作记忆容量（eWMC）的概念，而不是只有在理想条件下才能达到的最大容量上限。
The study of working memory capacity is of outmost importance in cognitive psychology as working memory is at the basis of general cognitive function. Although the working memory capacity limit has been thoroughly studied, its origin still remains a matter of strong debate. Only recently has the role of visual saliency in modulating working memory storage capacity been assessed experimentally and proved to provide valuable insights into working memory function. In the computational arena, attractor networks have successfully accounted for psychophysical and neurophysiological data in numerous working memory tasks given their ability to produce a sustained elevated firing rate during a delay period. Here we investigate the mechanisms underlying working memory capacity by means of a biophysically-realistic attractor network with spiking neurons while accounting for two recent experimental observations: 1) the presence of a visually salient item reduces the number of items that can be held in working memory, and 2) visually salient items are commonly kept in memory at the cost of not keeping as many non-salient items. Our model suggests that working memory capacity is determined by two fundamental processes: encoding of visual items into working memory and maintenance of the encoded items upon their removal from the visual display. While maintenance critically depends on the constraints that lateral inhibition imposes to the mnemonic activity, encoding is limited by the ability of the stimulated neural assemblies to reach a sufficiently high level of excitation, a process governed by the dynamics of competition and cooperation among neuronal pools. Encoding is therefore contingent upon the visual working memory task and has led us to introduce the concept of effective working memory capacity (eWMC) in contrast to the maximal upper capacity limit only reached under ideal conditions.
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DOI：
10.1073/pnas.93.24.13468
发表时间：
1996-11-26
影响因子：
11.1
作者：
Baddeley, A
通讯作者：
Baddeley, A
影响因子：
56.9
作者：
FUSTER, JM;ALEXANDER, GE
通讯作者：
ALEXANDER, GE
影响因子：
3.7
作者：
Amit, DJ;Bernacchia, A;Yakovlev, V
通讯作者：
Yakovlev, V
影响因子：
1.2
作者：
Brunel, N;Wang, XJ
通讯作者：
Wang, XJ
影响因子：
64.8
作者：
Gottlieb, JP;Kusunoki, M;Goldberg, ME
通讯作者：
Goldberg, ME