Altered First- but not Higher-Order Motion Aftereffect Strength in Individuals With Schizophrenia.

Area of Science:

• Neuroscience
• Visual Perception
• Psychiatric Disorders

Background:

• Schizophrenia (SZ) is characterized by altered integration of sensory input and prior knowledge, potentially affecting reality perception.
• Visual aftereffects, driven by neuronal adaptation, reveal how recent experiences influence perception and may be altered in SZ.
• Previous work showed stronger tilt aftereffects in SZ, suggesting altered cortical adaptation.

Purpose of the Study:

• To investigate alterations in neuronal adaptation within the visual hierarchy in individuals with schizophrenia (SZ).
• To determine if motion aftereffects differ between SZ and healthy controls (HC) and where in the visual cortex these differences are most pronounced.

Main Methods:

• Measured "first-order" (luminance-defined motion) and "higher-order" (non-luminance-defined motion) aftereffects in 55 individuals with SZ and 43 HC.
• First-order aftereffects are linked to adaptation in early visual cortex; higher-order aftereffects involve extrastriate areas.

Main Results:

• Individuals with SZ demonstrated significantly stronger first-order motion aftereffects compared to HC.
• No significant differences in higher-order motion aftereffects were observed between SZ and HC.
• These findings were not attributable to differences in task sensitivity, response bias, or visual acuity.

Conclusions:

• Altered neuronal adaptation in SZ appears more pronounced in earlier visual cortical stages (e.g., V1) than later stages (e.g., V5/MT).
• These results suggest that early visual processing alterations may play a role in the pathophysiology and clinical presentation of schizophrenia.