Task-based default mode network connectivity predicts cognitive impairment and negative symptoms in first-episode...

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Schizophrenia (SZ) is characterized by impaired source monitoring, affecting the ability to distinguish internal from external stimuli.
• Aberrant default mode network (DMN) connectivity is hypothesized to underlie these source monitoring deficits.
• Deficits in selective attention and inhibitory processing, indexed by the N100 event-related potential, are also prominent in SZ.

Purpose of the Study:

• To investigate the relationship between DMN connectivity and N100 measures in first-episode schizophrenia.
• To clarify the role of task-based DMN function in schizophrenia.

Main Methods:

• Electroencephalography (EEG) was used to assess DMN connectivity and N100 in 52 first-episode SZ patients and 25 healthy controls (HC).
• Participants underwent auditory paired-stimulus paradigms to elicit event-related potentials and measure DMN activity.

Main Results:

• First-episode SZ patients exhibited reduced theta-band DMN connectivity compared to HC during auditory stimulus presentation.
• Increased DMN connectivity in SZ was associated with better sustained attention and working memory performance, and lower negative symptom severity.
• DMN connectivity was not found to predict N100 measures in SZ.

Conclusions:

• Findings suggest reduced task-based DMN connectivity in first-episode schizophrenia, indicating disrupted neural networks supporting cognitive functions.
• Attentional processes, as measured by N100, appear to rely on neural mechanisms distinct from those implicated in DMN connectivity disruptions in SZ.