Default mode network activity in schizophrenia studied at resting state using probabilistic ICA.

Area of Science:

• Neuroscience
• Psychiatry
• Functional Neuroimaging

Background:

• Schizophrenia is associated with widespread brain dysfunction, observable even during resting states using functional MRI.
• The default mode network (DMN) is crucial for self-referential thought and has been implicated in neuropsychiatric disorders.

Purpose of the Study:

• To investigate differences in DMN functional connectivity between individuals with schizophrenia and healthy controls using resting-state fMRI.
• To explore the relationship between DMN alterations and symptom severity in schizophrenia.

Main Methods:

• Probabilistic independent component analysis (pICA) applied to resting-state fMRI data from 25 schizophrenia patients and 25 healthy controls.
• Automated algorithm used to identify and analyze the DMN component, comparing connectivity measures between groups.
• Region of interest (ROI) and voxel-wise analyses were performed.

Main Results:

• While overall DMN fit was similar, significant differences in connectivity were observed between groups.
• Healthy controls showed stronger DMN connectivity in prefrontal, precuneus, and parietal regions.
• Schizophrenia patients exhibited stronger DMN connectivity in the amygdala, orbitofrontal cortex, anterior cingulate, and temporal cortices.
• Negative symptoms in patients inversely correlated with activity in the right anterior prefrontal cortex.

Conclusions:

• Aberrant DMN connectivity is a key feature of schizophrenia's functional brain pathology.
• These DMN alterations are significantly associated with the manifestation of core schizophrenia symptoms.