Load-dependent functional connectivity deficits during visual working memory in first-episode psychosis

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Aberrant network connectivity is a key deficit in schizophrenia, potentially causing cognitive impairments.
• Previous studies indicate working memory network function is preserved in early illness but declines with increased task complexity.

Purpose of the Study:

• To investigate visual network connectivity in first-episode schizophrenia (FESz).
• To determine the contribution of network connectivity to working memory deficits that worsen with cognitive load.

Main Methods:

• Magnetoencephalography (MEG) recorded from 35 FESz patients and 28 healthy controls (HC) during a change detection task.
• Alpha-band connectivity analyzed using phase-locking value (PLV) with bilateral dorsal occipital (Occ) regions as seeds.
• Load-dependent connectivity modulation compared between FESz and HC groups.

Main Results:

• Occ exhibited significant load-modulated connectivity in HC but not FESz.
• FESz patients showed impaired PLV modulation between right Occ and specific frontal, temporal, and parietal regions.
• Reduced PLV in these connections correlated with increased reality distortion in FESz.

Conclusions:

• FESz patients cannot enhance visual working memory network communication with increasing cognitive demands.
• Impaired network communication is linked to positive symptoms in early psychosis.
• Findings highlight brain dysconnectivity in FESz and suggest potential therapeutic targets.