Crespo-García Maité, Zeiller Monika, Leupold Claudia, Kreiselmeyer Gernot, Rampp Stefan, Hamer Hajo M, Dalal Sarang S
Department of Psychology, University of Konstanz, 78464 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78464 Konstanz, Germany.
Department of Psychology, University of Konstanz, 78464 Konstanz, Germany.
Neuroimage. 2016 Nov 15;142:533-543. doi: 10.1016/j.neuroimage.2016.08.021. Epub 2016 Aug 10.
Human hippocampal theta oscillations play a key role in accurate spatial coding. Associative encoding involves similar hippocampal networks but, paradoxically, is also characterized by theta power decreases. Here, we investigated how theta activity relates to associative encoding of place contexts resulting in accurate navigation. Using MEG, we found that slow-theta (2-5Hz) power negatively correlated with subsequent spatial accuracy for virtual contextual locations in posterior hippocampus and other cortical structures involved in spatial cognition. A rare opportunity to simultaneously record MEG and intracranial EEG in an epilepsy patient provided crucial insights: during power decreases, slow-theta in right anterior hippocampus and left inferior frontal gyrus phase-led the left temporal cortex and predicted spatial accuracy. Our findings indicate that decreased slow-theta activity reflects local and long-range neural mechanisms that encode accurate spatial contexts, and strengthens the view that local suppression of low-frequency activity is essential for more efficient processing of detailed information.
人类海马体θ振荡在精确的空间编码中起着关键作用。联想编码涉及相似的海马体网络,但矛盾的是,其特征也是θ功率降低。在这里,我们研究了θ活动如何与地点背景的联想编码相关,从而实现精确导航。使用脑磁图(MEG),我们发现慢θ(2 - 5Hz)功率与后海马体及其他参与空间认知的皮质结构中虚拟背景位置的后续空间准确性呈负相关。在一名癫痫患者中同时记录脑磁图和颅内脑电图的罕见机会提供了关键见解:在功率降低期间,右前海马体和左额下回的慢θ相位领先于左颞叶皮质,并预测了空间准确性。我们的研究结果表明,慢θ活动的降低反映了编码精确空间背景的局部和远程神经机制,并强化了这样一种观点,即局部抑制低频活动对于更有效地处理详细信息至关重要。