Memory-Based Prediction Deficits and Dorsolateral Prefrontal Dysfunction in Schizophrenia.

Background: Theories suggest that people with schizophrenia (SZ) have problems generating predictions based on past experiences. The dorsolateral prefrontal cortex (DLPFC) and hippocampus participate in memory-based prediction. We used functional magnetic resonance imaging to investigate DLPFC and hippocampal function in healthy control (HC) subjects and people with SZ during memory-based prediction.

Disrupted Modulation of Alpha and Low Beta Oscillations Mediates Temporal Sequence Memory Deficits in People With Schizophrenia.

Background: People with schizophrenia (SZ) exhibit impaired episodic memory when relating objects to each other in time and space. Empirical studies and computational models suggest that low-frequency neural oscillations may be a mechanism by which the brain keeps track of temporal relationships during encoding and retrieval, with modulation of oscillatory power as sequences are learned. It is unclear whether sequence memory deficits in SZ are associated with altered neural oscillations.

Disruption of the anterior thalamic head direction signal following reduction of the hippocampal theta rhythm.

There is overlap between the structures containing head direction (HD) cells and those mediating the hippocampal theta rhythm, and both signals are thought to play an important role in spatial navigation. Previous research has shown that reversible inactivation of the medial septum attenuates hippocampal theta activity and disrupts path integration-based navigation. Although the HD signal reflects navigational performance, it is unclear whether theta rhythm contributes to the direction-specific activity of HD cells.

Task-specific Disruptions in Theta Oscillations during Working Memory for Temporal Order in People with Schizophrenia.

Prior studies demonstrated that neural oscillations are enhanced during working memory (WM) maintenance and that this activity can predict behavioral performance in healthy individuals. However, it is unclear whether the relationship holds for people with WM deficits. People with schizophrenia have marked WM deficits, and such deficits are most prominent when patients are required to process relationships between items, such as temporal order.