Theta Oscillations Support Prefrontal-hippocampal Interactions in Sequential Working Memory / 神经科学通报·英文版

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.

Neural mechanism and evaluation of decision-making function in obsessive-compulsive disorder / 上海交通大学学报（医学版）

Obsessive-compulsive disorder (OCD) is a chronic,disabling,mental disorder,which has been linked to significant abnormalities in certain brain areas,including the orbital frontal cortex and the anterior cingulate cortex.Neuroimaging studies have also shown that brain areas related to the decision-making function include the orbital frontal cortex and the dorsal prefrontal lobes.Furthermore,the association between OCD and decision-making function has been consistently demonstrated from a neurobiological perspective.Clinically,impaired decision-making ability is commonly observed in OCD patients,and there is a correlation between OCD and abnormal decision function.Decision-making tasks are typically divided into two types,decision-making under risk and decision-making under ambiguity,with the former commonly evaluated using the Iowa Gambling Task (IGT) and the latter using the Game of Dice Task (GDT).In this article the neural mechanism and evaluation methods of decision making in OCD were reviewed.