Functional cognitive and cortical abnormalities in chronic and first-admission schizophrenia

Area of Science:

• Neuroscience
• Cognitive Science
• Psychiatry

Background:

• Neural oscillations are increasingly recognized as fundamental to higher-order cognition.
• Schizophrenia (SZ) is characterized by cognitive decline and impaired sensory gating, observable in chronic (CHR) and first-admission (FA) patients.

Purpose of the Study:

• To investigate if altered event-related neural oscillations occur in early stages of schizophrenia.
• To determine if these oscillatory changes underpin sensory gating deficits and psychopathology development.

Main Methods:

• Compared cognitive performance (MCCB), neuromagnetic sensory gating (M50 ratio), and alpha oscillations (8-12Hz) in CHR (n=35), FA (n=31) patients, and healthy controls (HC, n=28).
• Utilized a paired-click task to assess evoked and induced oscillatory dynamics.

Main Results:

• Both CHR and FA groups showed poorer cognitive function, higher M50 ratios (impaired gating), and reduced induced alpha modulation compared to HC.
• Alpha power decrease correlated with M50 ratio in HC (posterior regions) but not SZ, while orbitofrontal alpha decrease correlated with M50 ratio in SZ but not HC.

Conclusions:

• Disrupted neural oscillatory dynamics are present even in early stages of schizophrenia.
• These alterations may contribute to deficits in information processing, memory, and overall cognitive function in schizophrenia.