Perceiving and acting in depth in Williams syndrome and typical development

Area of Science:

• Neuroscience
• Developmental Psychology
• Ophthalmology

Background:

• Individuals with Williams syndrome (WS), a neurodevelopmental disorder, often experience difficulties with depth perception and acting in depth.
• Research on the specific nature and root causes (ocular vs. perceptual) of these depth processing deficits in WS is limited.

Purpose of the Study:

• To assess the extent of deficits in stereopsis (binocular vision) and depth-action in individuals with WS compared to typically developing (TD) controls.
• To investigate the relationship between stereoacuity and performance on depth-action tasks in both groups.
• To determine if depth perception deficits in WS are ocular or perceptual in origin.

Main Methods:

• Compared stereoacuity and depth-action performance in individuals with WS and age-matched TD participants.
• Assessed monocular and binocular depth-action abilities.
• Analyzed the correlation between stereoacuity and binocular action in depth.

Main Results:

• Stereoacuity in the WS group was significantly poorer than in the TD group, with one-third of WS individuals showing no stereopsis.
• No differences were found in monocular depth-action between WS and TD groups.
• Individuals with WS and no stereopsis performed significantly worse on binocular depth-action tasks compared to TD participants and WS participants with stereopsis.

Conclusions:

• WS is characterized by significant deficits in binocular depth perception and action, not monocular depth perception.
• Binocular action in depth may serve as a screening tool for stereodeficits in WS.
• Interventions focusing on monocular depth cues could help compensate for poor stereopsis in WS.