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Published on: July 21, 2020
Visual depth processing in Williams-Beuren syndrome
J N Van der Geest1, G C Lagers-van Haselen, J M van Hagen
1Department of Neuroscience, Erasmus MC, PO Box 1738, 3000 DR Rotterdam, The Netherlands. j.vandergeest@erasmusmc.nl
Experimental Brain Research
|June 21, 2005
Summary
Patients with Williams-Beuren Syndrome (WBS) can perceive depth but struggle using it for movement guidance without visual feedback. This suggests WBS motor deficits aren't due to poor distance judgment.
Area of Science:
- Neuroscience
- Developmental Psychology
- Ophthalmology
Background:
- Williams-Beuren Syndrome (WBS) is associated with visuo-motor integration deficits, impacting activities like stair navigation.
- The underlying cause of these motor challenges in WBS remains unclear, with potential links to visual perception or motor control.
Purpose of the Study:
- To investigate whether visuo-motor deficits in WBS stem from impaired visual depth perception or difficulties in utilizing depth information for movement guidance.
- To differentiate between perceptual and motor utilization deficits in WBS patients.
Main Methods:
- Assessed monocular and binocular visual depth perception in 33 WBS patients and controls.
- Recorded hand movements towards targets with and without visual feedback of hand position.
- Compared performance between WBS patients and a control group.
Main Results:
- WBS patients could perceive depth cues requiring global processing but 49% lacked stereopsis.
- Without visual feedback, WBS patients overshot target movements on average.
- Visual feedback restored normal hand movement accuracy in WBS patients.
Conclusions:
- WBS patients can derive depth from complex spatial relationships.
- Impairments in using depth information for movement guidance, particularly without visual feedback, are evident in WBS.
- Difficulties with tasks like stair descent in WBS are likely not due to an inability to judge distance but rather impaired sensorimotor integration.
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