Early and late components of EEG delay activity correlate differently with scene working memory performance
Early and late components of EEG delay activity correlate differently with scene working memory performance
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DOI：
10.1371/journal.pone.0186072
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发表时间：
2017-10-10
期刊：
影响因子：
3.7
通讯作者：
Reichert, Chelsea P.
中科院分区：
文献类型：
--
作者：
Ellmore, Timothy M.;Ng, Kenneth;Reichert, Chelsea P.
工作记忆延迟期间持续且升高的活动长期以来一直被认为是在短时间间隔内维持信息的主要神经关联。最近，根据多种神经记录模式和分析水平产生的发现，这一想法被重新解释。为了进一步研究活动的持续或短暂性质，在具有相对较长的六秒延迟和新场景作为刺激的斯滕伯格工作记忆范式的执行过程中，对具有高密度脑电图的人类进行了延迟期活动的时间谱演化（TSE）检查。使用不同的试验窗口持续时间和不同的 TSE 计算基线期进行多项分析。传感器水平分析揭示了延迟期间的短暂活动而不是持续活动。具体来说，分析中一致的发现是，在延迟期的前三秒早期就发现了涵盖 theta 范围的高振幅活动。延迟期早期活动的增加与随后区分新旧探测场景的能力呈正相关。源级信号估计表明右顶叶区域存在短暂的早期延迟活动，与工作记忆能力呈正相关。这种结果模式增加了最近的证据，即短暂而非持续的延迟期活动支持视觉工作记忆性能。研究结果讨论了同步和异步区域内和区域间神经传递，以及选择表达时间谱延迟活动变化的最佳基线。
Sustained and elevated activity during the working memory delay period has long been considered the primary neural correlate for maintaining information over short time intervals. This idea has recently been reinterpreted in light of findings generated from multiple neural recording modalities and levels of analysis. To further investigate the sustained or transient nature of activity, the temporal-spectral evolution (TSE) of delay period activity was examined in humans with high density EEG during performance of a Sternberg working memory paradigm with a relatively long six second delay and with novel scenes as stimuli. Multiple analyses were conducted using different trial window durations and different baseline periods for TSE computation. Sensor level analyses revealed transient rather than sustained activity during delay periods. Specifically, the consistent finding among the analyses was that high amplitude activity encompassing the theta range was found early in the first three seconds of the delay period. These increases in activity early in the delay period correlated positively with subsequent ability to distinguish new from old probe scenes. Source level signal estimation implicated a right parietal region of transient early delay activity that correlated positively with working memory ability. This pattern of results adds to recent evidence that transient rather than sustained delay period activity supports visual working memory performance. The findings are discussed in relation to synchronous and desynchronous intra-and inter-regional neural transmission, and choosing an optimal baseline for expressing temporal-spectral delay activity change.