Sarnthein J, Petsche H, Rappelsberger P, Shaw G L, von Stein A
Institut für Neurophysiologie, Universität Wien, Währingerstrasse 17, A-1090 Wien, Austria.
Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):7092-6. doi: 10.1073/pnas.95.12.7092.
We measured coherence between the electroencephalogram at different scalp sites while human subjects performed delayed response tasks. The tasks required the retention of either verbalizable strings of characters or abstract line drawings. In both types of tasks, a significant enhancement in coherence in the theta range (4-7 Hz) was found between prefrontal and posterior electrodes during 4-s retention intervals. During 6-s perception intervals, far fewer increases in theta coherence were found. Also in other frequency bands, coherence increased; however, the patterns of enhancement made a relevance for working memory processes seem unlikely. Our results suggest that working memory involves synchronization between prefrontal and posterior association cortex by phase-locked, low frequency (4-7 Hz) brain activity.
我们在人类受试者执行延迟反应任务时，测量了不同头皮部位脑电图之间的相干性。这些任务要求保留可言语化的字符串或抽象线条图。在这两种类型的任务中，发现在4秒的保留间隔期间，前额叶和后电极之间在θ频段（4 - 7赫兹）的相干性显著增强。在6秒的感知间隔期间，发现θ相干性增加的情况要少得多。在其他频段，相干性也增加了；然而，增强模式似乎与工作记忆过程无关。我们的结果表明，工作记忆涉及通过锁相的低频（4 - 7赫兹）脑活动，使前额叶和后联合皮层之间实现同步。
