Yordanova J, Kolev V
Institute of Physiology, Bulgarian Academy of Science, Sofia.
Neuroreport. 1998 Oct 5;9(14):3159-64. doi: 10.1097/00001756-199810050-00007.
Recent findings indicate that the electroencephalographic alpha (7-14 Hz) activity is functionally involved in cognitive brain functioning, but the issue of whether and how event-related alpha oscillations may relate to the processes indexed by the P300 component of the event-related brain potentials (ERPs) has not been addressed. The present study assessed the effect of auditory oddball task processing on slow (7-10 Hz) and fast (10-14 Hz) alpha activity from the P300 latency range. ERPs from mentally counted targets (20%) and uncounted non-targets (80%) were recorded at Fz, Cz, and Pz in nine subjects Single-sweep phase-locking, power of phase-locked, and power of non-phase-locked alpha responses during P300 activity were quantified. The results demonstrated that larger and more synchronized phase-locked fast alpha components at anterior (frontal-central) locations, with reduced non-phase-locked slow alpha responses at the parietal site were produced by targets relative to non-targets. Because the simultaneously recorded P300 and alpha activity manifested a similar sensitivity to the oddball task, event-related alpha appears to be functionally associated with the cognitive processing demands eliciting P300. Also, evidence is provided for the functional involvement of frontally synchronized and enhanced alpha oscillations in task processing.
最近的研究结果表明，脑电图α波（7-14赫兹）活动在大脑认知功能中发挥作用，但事件相关的α振荡是否以及如何与事件相关脑电位（ERP）的P300成分所索引的过程相关这一问题尚未得到解决。本研究评估了听觉oddball任务处理对P300潜伏期范围内慢（7-10赫兹）和快（10-14赫兹）α波活动的影响。在九名受试者的Fz、Cz和Pz处记录了心理计数目标（20%）和未计数非目标（80%）的ERP。对P300活动期间的单次扫描锁相、锁相功率和非锁相α反应功率进行了量化。结果表明，与非目标相比，目标在前部（额中央）位置产生了更大且更同步的锁相快α成分，同时顶叶部位的非锁相慢α反应减少。由于同时记录的P300和α活动对oddball任务表现出相似的敏感性，事件相关α似乎在功能上与引发P300的认知处理需求相关。此外，还提供了额叶同步增强的α振荡在任务处理中发挥功能作用的证据。
