Klinik für Neurochirurgie, UniversitätsSpital und Universität Zürich, 8091 Zürich, Switzerland.
Zentrum für Neurowissenschaften Zürich, ETH Zürich, Zürich, Switzerland.
Sci Adv. 2019 Mar 27;5(3):eaav3687. doi: 10.1126/sciadv.aav3687. eCollection 2019 Mar.
The maintenance of items in working memory relies on persistent neural activity in a widespread network of brain areas. To investigate the influence of load on working memory, we asked human subjects to maintain sets of letters in memory while we recorded single neurons and intracranial encephalography (EEG) in the medial temporal lobe and scalp EEG. Along the periods of a trial, hippocampal neural firing differentiated between success and error trials during stimulus encoding, predicted workload during memory maintenance, and predicted the subjects' behavior during retrieval. During maintenance, neuronal firing was synchronized with intracranial hippocampal EEG. On the network level, synchronization between hippocampal and scalp EEG in the theta-alpha frequency range showed workload dependent oscillatory coupling between hippocampus and cortex. Thus, we found that persistent neural activity in the hippocampus participated in working memory processing that is specific to memory maintenance, load sensitive and synchronized to the cortex.
项目在工作记忆中的维持依赖于大脑广泛区域网络中持续的神经活动。为了研究负荷对工作记忆的影响，我们要求人类受试者在记忆中保持字母集，同时在大脑中颞叶内侧和头皮脑电图记录单个神经元和颅内脑电图。在试验期间，海马神经放电在刺激编码期间区分成功和错误试验，预测记忆维持期间的工作量，并预测受试者在检索期间的行为。在维持期间，神经元放电与颅内海马 EEG 同步。在网络层面上，海马和头皮 EEG 在 theta-alpha 频率范围内的同步显示了海马和皮层之间与工作量相关的振荡耦合。因此，我们发现海马体中持续的神经活动参与了特定于记忆维持的工作记忆处理，对负荷敏感且与皮层同步。
