Puszta András
Helgeland Hospital, Department of Neuropsychology, Mosjøen, Norway.
University of Oslo, Department of Psychology, Oslo, Norway.
Neuroimage Rep. 2022 Aug 25;2(4):100124. doi: 10.1016/j.ynirp.2022.100124. eCollection 2022 Dec.
This paper aims to establish how frontal midline theta and theta-gamma coupling are altered by memory load as well as by recall performance during a verbal digit span task using an open EEG dataset. Traditional behavioral scores, as well as new measure were used, as the recall accuracy as a function of the order of the digits followed a sigmoid curve. The new behavioral score was strongly correlated with traditional measures. The EEG results show that neither the resting state theta nor the theta during the digit span task is predictive of the task performance. However, there was a strong positive correlation between cognitive load and theta power as well as a negative correlation between cognitive load and theta peak frequency during the task. These results are in line with earlier studies indicating that frontal midline theta is modulated by cognitive load rather than memory performance. Furthermore, there was an increased alpha-beta cross frequency coupling during resting state but that was not correlated with the performance of the upcoming memory task. During the task the cross-frequency coupling was minimal, and it did not correlate with memory performance nor with task load, that raises the possibility that EEG is not sensitive enough for cross-frequency coupling measures.
本文旨在利用一个开放的脑电图数据集，确定在言语数字广度任务中，额叶中线θ波以及θ-γ耦合如何因记忆负荷和回忆表现而发生改变。使用了传统行为评分以及新的测量方法，因为数字顺序的回忆准确率呈S形曲线。新的行为评分与传统测量方法高度相关。脑电图结果表明，静息状态下的θ波以及数字广度任务期间的θ波均无法预测任务表现。然而，任务期间认知负荷与θ波功率之间存在强正相关，认知负荷与θ波峰值频率之间存在负相关。这些结果与早期研究一致，表明额叶中线θ波受认知负荷而非记忆表现的调节。此外，静息状态下α-β交叉频率耦合增加，但这与即将进行的记忆任务的表现无关。任务期间交叉频率耦合最小，且与记忆表现和任务负荷均无关联，这增加了脑电图对交叉频率耦合测量不够敏感的可能性。
