Visual Deficits in Contrast and Depth Perception in Psychotic Disorders: Implications for a Neural Hierarchy.

Area of Science:

• Neuroscience
• Visual Perception
• Psychiatric Disorders

Background:

• Understanding psychotic disorders (PDs) requires identifying affected brain regions and their interactions.
• The hierarchical visual system, from retina to visual cortex, models neurobehavioral mechanisms.
• Assessing visual contrast detection and binocular depth perception offers insights into PDs.

Purpose of the Study:

• To investigate visual processing deficits in individuals with psychotic disorders (PDs).
• To compare performance on contrast detection and depth perception tasks between PDs and healthy controls (HCs).
• To explore the relationship between visual deficits and cognitive/attentional functions in PDs.

Main Methods:

• Assessed psychophysical sensitivity to contrast and binocular disparity in 53 PDs and 58 HCs.
• Matched stimulus features across tasks, varying only the primary variable of interest.
• Quantified performance using normalized area under psychometric curves.

Main Results:

• PD group showed significant impairments in contrast detection (p < .007) and depth perception (p < .021) versus HCs.
• Performance on both tasks correlated in the PD group, but not in HCs.
• Depth perception deficits were more pronounced than contrast detection deficits in PDs; additional cognitive/attentional dysfunctions were noted.

Conclusions:

• Findings suggest a progressive accumulation of visual processing deficits along the visual hierarchy in psychosis.
• Visual system hierarchy provides a framework for understanding neurobiological changes in PDs.