Cognition and Brain Plasticity Unit, Institute of Biomedical Research of Bellvitge (IDIBELL), L'Hospitalet, Barcelona, Spain; Department of Basic Psychology, University of Barcelona, Barcelona, Spain.
Neuroimage. 2014 Jan 15;85 Pt 2:730-7. doi: 10.1016/j.neuroimage.2013.08.029. Epub 2013 Aug 23.
Remembering autobiographical events can be associated with detailed visual imagery. The medial temporal lobe (MTL), precuneus and prefrontal cortex are held to jointly enable such vivid retrieval, but how these regions are orchestrated remains unclear. An influential prediction from animal physiology is that neural oscillations in theta frequency may be important. In this experiment, participants prospectively collected audio recordings describing personal autobiographical episodes or semantic knowledge over 2 to 7 months. These were replayed as memory retrieval cues while recording brain activity with magnetoencephalography (MEG). We identified a peak of theta power within a left MTL region of interest during both autobiographical and General Semantic retrieval. This MTL region was selectively phase-synchronized with theta oscillations in precuneus and medial prefrontal cortex, and this synchrony was higher during autobiographical as compared to General Semantic knowledge retrieval. Higher synchrony also predicted more detailed visual imagery during retrieval. Thus, theta phase-synchrony orchestrates in humans the MTL with a distributed neocortical memory network when vividly remembering autobiographical experiences.
回忆自传事件可能与详细的视觉意象有关。内侧颞叶（MTL）、楔前叶和前额叶皮层被认为共同实现了这种生动的检索，但这些区域是如何协调的仍然不清楚。动物生理学的一个有影响力的预测是，θ频率的神经振荡可能很重要。在这项实验中，参与者前瞻性地收集了 2 到 7 个月的音频记录，描述个人自传事件或语义知识。当使用脑磁图（MEG）记录大脑活动时，这些被回放作为记忆检索线索。我们在自传和一般语义检索过程中都在左 MTL 感兴趣区域内发现了一个 theta 功率峰值。这个 MTL 区域与楔前叶和内侧前额叶皮层的 theta 振荡选择性地相位同步，并且在自传式回忆中比在一般语义知识回忆中同步性更高。更高的同步性也预示着在检索过程中会产生更详细的视觉意象。因此，当生动地回忆自传体经历时，theta 相位同步在人类中协调了 MTL 与分布式新皮层记忆网络。
