The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation. This stereoelectroencephalography (SEEG) study investigated how the dorsolateral prefrontal cortex (DLPFC) interacts with the hippocampus in the online processing of sequential information. Twenty patients with epilepsy (eight women, age 27.6 ± 8.2 years) completed a line ordering task with SEEG recordings over the DLPFC and the hippocampus. Participants showed longer thinking times and more recall errors when asked to arrange random lines clockwise (random trials) than to maintain ordered lines (ordered trials) before recalling the orientation of a particular line. First, the ordering-related increase in thinking time and recall error was associated with a transient theta power increase in the hippocampus and a sustained theta power increase in the DLPFC (3–10 Hz). In particular, the hippocampal theta power increase correlated with the memory precision of line orientation. Second, theta phase coherences between the DLPFC and hippocampus were enhanced for ordering, especially for more precisely memorized lines. Third, the theta band DLPFC → hippocampus influence was selectively enhanced for ordering, especially for more precisely memorized lines. This study suggests that theta oscillations may support DLPFC-hippocampal interactions in the online processing of sequential information.

前额叶皮层和海马体可能支持情景记忆和空间导航之外的顺序工作记忆。这项立体脑电图 (SEEG) 研究调查了背外侧前额叶皮层 (DLPFC) 在连续信息的在线处理中如何与海马体相互作用。20 名癫痫患者（8 名女性，年龄 27.6 ± 8.2 岁）通过 DLPFC 和海马区的 SEEG 记录完成了线路排序任务。当被要求在回忆特定线的方向之前顺时针排列随机线（随机试验）时，参与者表现出更长的思考时间和更多的回忆错误，而不是在回忆特定线的方向之前保持有序线（有序试验）。首先，与排序相关的思维时间和回忆错误的增加与海马体中短暂的 theta 功率增加和 DLPFC（3-10 Hz）中的持续 theta 功率增加有关。特别是，海马θ功率的增加与线方向的记忆精度相关。其次，DLPFC 和海马体之间的 θ 相一致性在排序方面得到增强，尤其是对于更精确的记忆线。第三，Theta带DLPFC→海马体的影响被选择性地增强以进行排序，特别是对于更精确地记忆的线。这项研究表明，theta 振荡可能支持 DLPFC-海马在序列信息的在线处理中的相互作用。