Slotnick Scott D, Moo Lauren R, Kraut Michael A, Lesser Ronald P, Hart John
Department of Psychology, Johns Hopkins University, Baltimore, MD 21218, USA.
Proc Natl Acad Sci U S A. 2002 Apr 30;99(9):6440-3. doi: 10.1073/pnas.092514899. Epub 2002 Apr 23.
Human scalp electroencephalographic rhythms, indicative of cortical population synchrony, have long been posited to reflect cognitive processing. Although numerous studies employing simultaneous thalamic and cortical electrode recording in nonhuman animals have explored the role of the thalamus in the modulation of cortical rhythms, direct evidence for thalamocortical modulation in human has not, to our knowledge, been obtained. We simultaneously recorded from thalamic and scalp electrodes in one human during performance of a cognitive task and found a spatially widespread, phase-locked, low-frequency rhythm (7-8 Hz) power decrease at thalamus and scalp during semantic memory recall. This low-frequency rhythm power decrease was followed by a spatially specific, phase-locked, fast-rhythm (21-34 Hz) power increase at thalamus and occipital scalp. Such a pattern of thalamocortical activity reflects a plausible neural mechanism underlying semantic memory recall that may underlie other cognitive processes as well.
长期以来，人们一直认为，反映皮层群体同步性的人类头皮脑电图节律能够反映认知加工过程。尽管众多在非人类动物中同时进行丘脑和皮层电极记录的研究已经探讨了丘脑在调节皮层节律中的作用，但据我们所知，尚未获得人类丘脑皮质调节的直接证据。我们在一名人类执行认知任务期间，同时记录了丘脑和头皮电极的数据，发现在语义记忆回忆过程中，丘脑和头皮出现了空间广泛、锁相的低频节律（7-8赫兹）功率下降。这种低频节律功率下降之后，丘脑和枕部头皮出现了空间特定、锁相的快节律（21-34赫兹）功率增加。这种丘脑皮质活动模式反映了语义记忆回忆背后一种合理的神经机制，这种机制可能也是其他认知过程的基础。
