Abnormal cortical neural synchrony during working memory in schizophrenia.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Psychiatry

Background:

• Working memory (WM) impairment is a core deficit in schizophrenia.
• Understanding the neural underpinnings of WM deficits is crucial for developing targeted interventions.

Purpose of the Study:

• Investigate cortical oscillatory activity during a spatial working memory task in people with schizophrenia (PSZ).
• Identify specific neural synchrony abnormalities associated with encoding, maintenance, and retrieval/manipulation processes in PSZ.

Main Methods:

• Magnetoencephalography (MEG) was used to examine time-frequency synchronous energy of cortical source signals.
• Analysis focused on prefrontal, parietal, and visual cortices during a spatial WM task.
• Data were compared between 12 PSZ and 13 healthy controls (HC).

Main Results:

• PSZ demonstrated performance deficits across WM loads and durations compared to HC.
• Deficits in theta and delta event-related synchrony (ERS) during encoding predicted WM performance.
• Abnormalities in beta event-related desynchrony (ERD) during maintenance and reduced delta/theta and gamma ERS during retrieval were observed in PSZ.

Conclusions:

• Schizophrenia is associated with widespread cortical neural oscillatory deficits during WM tasks.
• Abnormal prefrontal theta-frequency ERS during encoding is a key predictor of WM impairment in schizophrenia.
• Time-frequency-spatial analysis reveals process- and frequency-specific neural synchrony abnormalities underlying WM deficits.