Oscillations in the alpha band (9-12 Hz) increase with memory load during retention in a short-term memory task
Oscillations in the alpha band (9-12 Hz) increase with memory load during retention in a short-term memory task
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DOI：
10.1093/cercor/12.8.877
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发表时间：
2002-08-01
期刊：
影响因子：
3.7
通讯作者：
Lisman, JE
中科院分区：
文献类型：
--
作者：
Jensen, O;Gelfand, J;Lisman, JE
为了研究大脑振荡在工作记忆中的作用，我们在修改后的斯滕伯格任务的保留间隔期间记录了头皮脑电图（EEG）。保留间隔期间脑电图的功率谱分析显示在 9-12 Hz 处有一个清晰的峰值，该频率位于 α 频段 (8-13 Hz)。与之前的观点（阿尔法带振荡代表大脑“闲置”）明显相冲突，我们发现阿尔法峰值随着工作记忆中保存的项目数量而系统性地增加。增强在后部和双侧中央区域显着。后部区域的增强很可能是由靠近顶枕裂的众所周知的α节律来解释的，而横向增强可以由躯体运动皮层的来源来解释。时频分析显示，在 2.8 秒保留间隔的最后 2.5 秒中存在增强，并且 α 功率在探测后迅速减弱。 α 的负载依赖性和严格的时间调节提供了强有力的证据，证明 α 生成系统直接或间接与负责工作记忆的电路相关。尽管仅在一名受试者中检测到 θ 频带（5-8 Hz）中的清晰峰值，但其他证据表明 θ 波存在并且在工作记忆中也发挥着作用。讨论了有关 α 带活动在工作记忆中的作用的假设。
To study the role of brain oscillations in working memory, we recorded the scalp electroencephalogram (EEG) during the retention interval of a modified Sternberg task. A power spectral analysis of the EEG during the retention interval revealed a clear peak at 9-12 Hz, a frequency in the alpha band (8-13 Hz). In apparent conflict with previous ideas according to which alpha band oscillations represent brain 'idling', we found that the alpha peak systematically increased with the number of items held in working memory. The enhancement was prominent over the posterior and bilateral central regions. The enhancement over posterior regions is most likely explained by the well known alpha rhythm produced close to the parietal-occipital fissure, whereas the lateral enhancement could be explained by sources in somato-motor cortex. A time-frequency analysis revealed that the enhancement was present throughout the last 2.5 s of the 2.8 s retention interval and that alpha power rapidly diminished following the probe. The load dependence and the tight temporal regulation of alpha provide strong evidence that the alpha generating system is directly or indirectly linked to the circuits responsible for working memory. Although a clear peak in the theta band (5-8 Hz) was only detectable in one subject, other lines of evidence indicate that theta occurs and also has a role in working memory. Hypotheses concerning the role of alpha band activity in working memory are discussed.