Serial representation of items during working memory maintenance at letter-selective cortical sites.
Serial representation of items during working memory maintenance at letter-selective cortical sites.
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DOI：
10.1371/journal.pbio.2003805
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发表时间：
2018-08
期刊：
影响因子：
9.8
通讯作者：
Lisman J
中科院分区：
文献类型：
--
作者：
Bahramisharif A;Jensen O;Jacobs J;Lisman J
工作记忆的一个关键组成部分是同时记住多个项目的能力。为了了解人类大脑是如何在记忆中维持多个项目的，我们检查了神经外科患者在执行工作记忆任务时神经振荡的直接大脑记录。我们对数据进行了分析，通过识别具有宽带伽马活动的记录位点来识别单个记忆项目的神经表征，这些记录位点根据受试者所看到的字母的身份而变化。接下来，我们测试了先前提出的工作记忆模型，该模型假设单个记忆项目的神经表征顺序发生在θ / α循环的不同阶段。与该模型一致的是，维持过程中刺激相关的伽马活动发生时的θ / α振荡的相位反映了列表呈现的顺序。这些结果表明，工作记忆是由一个由耦合的θ / α和γ振荡协调的皮层相编码组织的，更广泛地说，为工作记忆中的项目序列表征提供了支持。在我们的日常生活中，我们经常需要在工作记忆中保持多个活动项目——例如，电话号码中的一系列数字。大脑是如何完成这项任务的？1995年，Lisman和Idiart提出了一种支持多项目工作记忆的机制，即单个记忆项目按顺序重复激活。在theta/alpha （7 - 13hz）和gamma （> - 30hz）范围内的耦合振荡脑活动支持了激活的时间协调性。利用人类大脑的颅内记录，我们现在报告了对这一方案的实验支持。特别是，当受试者记住一系列工作记忆项目时，它会激活θ / α振荡。与此同时，大脑显示出特定项目的伽马活动激活，出现在与项目在序列中的位置相对应的θ / α阶段。研究表明，皮质耦合振荡对协调多项目工作记忆的维持是重要的。
A key component of working memory is the ability to remember multiple items simultaneously. To understand how the human brain maintains multiple items in memory, we examined direct brain recordings of neural oscillations from neurosurgical patients as they performed a working memory task. We analyzed the data to identify the neural representations of individual memory items by identifying recording sites with broadband gamma activity that varied according to the identity of the letter a subject viewed. Next, we tested a previously proposed model of working memory, which had hypothesized that the neural representations of individual memory items sequentially occurred at different phases of the theta/alpha cycle. Consistent with this model, the phase of the theta/alpha oscillation when stimulus-related gamma activity occurred during maintenance reflected the order of list presentation. These results suggest that working memory is organized by a cortical phase code coordinated by coupled theta/alpha and gamma oscillations and, more broadly, provide support for the serial representation of items in working memory. In our daily lives, we often have to keep multiple items active in our working memory—for instance, a series of digits in a phone number. How does the brain perform this task? In 1995, Lisman and Idiart proposed that multi-item working memory was supported by a mechanism in which individual memory items are repeatedly activated in sequence. The temporal coordination of the activation was supported by coupled oscillatory brain activity in the theta/alpha (7–13 Hz) and gamma range (>30 Hz). Using intracranial recordings from the human brain, we now report experimental support for this scheme. In particular, when subjects remembered a list of working memory items, it activated theta/alpha oscillations. Simultaneously, the brain showed item-specific activations of gamma activity that appeared at a theta/alpha phase corresponding to the item’s position in the sequence. The work demonstrates that coupled cortical oscillations are important for coordinating the maintenance of multi-item working memory.
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影响因子：
13.9
作者：
Buzsáki G;Wang XJ
通讯作者：
Wang XJ
影响因子：
56.9
作者：
FUSTER, JM;ALEXANDER, GE
通讯作者：
ALEXANDER, GE
DOI：
10.1523/jneurosci.4122-11.2012
发表时间：
2012-01-11
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Belluscio MA;Mizuseki K;Schmidt R;Kempter R;Buzsáki G
通讯作者：
Buzsáki G
影响因子：
2
作者：
Chaieb, Leila;Leszczynski, Marcin;Fell, Juergen
通讯作者：
Fell, Juergen
影响因子：
16.2
作者：
Atallah, Bassam V.;Scanziani, Massimo
通讯作者：
Scanziani, Massimo