The effects of memory load on event-related EEG desynchronization and synchronization
The effects of memory load on event-related EEG desynchronization and synchronization
复制标题
DOI：
10.1016/s1388-2457(00)00429-6
复制
发表时间：
2000-11-01
影响因子：
4.7
通讯作者：
Hämäläinen, H
中科院分区：
文献类型：
--
作者：
Krause, CM;Sillanmäki, L;Hämäläinen, H
目的：探讨工作记忆负荷对几个窄频段脑电信号事件相关去同步(ERD)和同步(ERS)的影响。方法：研究24名正常受试者在4-6、6-8、8-10和10-12赫兹脑电频段的事件相关去同步(ERD/ERS)反应。在6-8和8-10 Hz频段，前向ERS在2-Back(最高记忆负荷)条件下的诱发更为明显。与8-10赫兹频段的反应相比，在10-12赫兹频段，2-BACK实验条件诱发的ERD最大。结论：在最高记忆负荷(2-BACK)实验条件下，极有可能超出注意能力，导致6-8和8-10 HZ的ERS。这可能反映了当需要和利用替代策略时，不再参与任务完成的大脑区域(额叶皮质)受到抑制。这些更“认知”的策略随后被反映为10-12赫兹ERD的增加。此外，我们的结果支持这样的假设，即不同窄频段的同时记录的ERD/ERS响应是不同的，反映了信息处理的不同方面。(C)2000爱思唯尔爱尔兰科学有限公司。保留所有权利。
Objectives: To examine the effects of working memory load on the event-related desynchronization (ERD) and synchronization (ERS) of several narrow EEG frequency bands.Methods: ERD/ERS responses of the 4-6, 6-8, 8-10 and 10-12 Hz EEG frequency bands were studied in 24 normal subjects performing a visual sequential letter task (so-called n-back task) in which memory load was varied from 0 to 2.Results: In the 3-6 Hz theta frequency band, a long-lasting synchronization was observed in the anterior electrodes, especially after the presentation of targets. In the 6-8 and 8-10 Hz frequency bands, anterior ERS was elicited especially in the 2-back condition (highest memory load). In contrast to the responses of the 8-10 Hz frequency band, in the 10-12 Hz frequency band the 2-back experimental condition elicited the greatest ERD.Conclusions: In the highest memory load (2-back) experimental condition the attentional capacities were most probably exceeded, resulting in 6-8 and 8-10 Hz ERS. This might reflect an inhibition of such brain areas (frontal cortices) no longer involved in task completion when alternative strategies are needed and utilized. These more 'cognitive' strategies were then reflected as an increase in 10-12 Hz ERD. Additionally, our results support the assumption that the simultaneously recorded ERD/ERS responses of different narrow EEG frequency bands differ and reflect distinct aspects of information processing. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.