Fronto-parietal network function during cued visual search in the first-episode schizophrenia spectrum

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Cognitive impairments, particularly in selective attention, are prominent in schizophrenia from disease onset.
• These deficits significantly impact patient morbidity and daily functioning.

Purpose of the Study:

• To investigate fronto-parietal attention network (FPAN) functioning during visual search cueing in first-episode schizophrenia spectrum patients (FE).
• To examine the relationship between FPAN activity, symptom burden, and community functioning in FE patients.

Main Methods:

• Magnetoencephalography (MEG) recorded brain activity in 38 FE patients and 38 healthy controls (HC).
• Participants completed a visual search task with pop-out and serial search conditions.
• Activity was compared between groups in bilateral FPAN regions (FEF, IFG, MCC, IPS) during cue presentation.

Main Results:

• FE patients showed greater right hemisphere inferior frontal gyrus (IFG) activity than HC, despite poorer performance.
• In FE patients, heightened activity in right frontal eye fields (FEF) and IFG correlated with faster response times.
• Increased right intraparietal sulcus (IPS) and left IFG activity in FE patients was linked to reduced negative symptoms and better community functioning, respectively.

Conclusions:

• First-episode schizophrenia patients exhibit altered FPAN activity, suggesting inefficient cognitive control possibly as a compensatory mechanism.
• This compensatory strategy may be associated with less severe illness presentations.
• Findings highlight neural substrates of negative symptoms and cognitive deficits at schizophrenia onset.