Reversed hemispheric asymmetry during simple visual perception in schizophrenia

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• Sensory information processing involves hierarchical progression from primary to multimodal brain areas.
• Hemispheric dominance is established for certain sensory processing functions.
• Altered brain activity and hemispheric asymmetry are implicated in schizophrenia.

Purpose of the Study:

• To investigate differences in regional cerebral blood flow (rCBF) patterns between normal and schizophrenic subjects during a passive visual task.
• To examine the role of hemispheric asymmetry in sensory processing in schizophrenia.

Main Methods:

• Employed positron emission tomography (PET) to measure regional cerebral blood flow (rCBF).
• Subjects underwent two scanning sessions while viewing a stationary visual noise pattern.
• Compared rCBF changes between the two scanning sessions in normal and schizophrenic participants.

Main Results:

• Normal subjects demonstrated a significant reduction in right hemisphere rCBF during the second visual task.
• Schizophrenic subjects showed significant increases in right hemisphere rCBF and decreases in the left hemisphere.
• These findings suggest altered hemispheric processing in schizophrenia.

Conclusions:

• The results support the hypothesis of reversed hemispheric asymmetry in sensory information processing in schizophrenia.
• This study provides neuroimaging evidence for atypical brain function in individuals with schizophrenia.
• Understanding these hemispheric differences may offer insights into the pathophysiology of schizophrenia.