Reduced parietal and visual cortical activation during global processing in Williams syndrome.

Area of Science:

• Neuroscience
• Genetics
• Cognitive Psychology

Background:

• Williams syndrome (WS) is a neurodevelopmental disorder with known genetic causes.
• Previous research indicates individuals with WS have difficulties integrating local visual details into global patterns.

Purpose of the Study:

• To investigate global visual processing abilities in individuals with Williams syndrome.
• To compare brain activity using fMRI between individuals with WS and a typically developed (TD) group during a global processing task.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan 10 participants with WS and 10 age- and sex-matched TD controls.
• Participants performed a task requiring the integration of local image elements into global configurations.

Main Results:

• Behaviorally, participants with WS were less accurate in global processing compared to the TD group.
• fMRI revealed reduced activation in the visual and parietal cortices of individuals with WS.
• Elevated activation was observed in posterior thalamic nuclei in the WS group, with normal activation in the ventral occipitotemporal cortex.

Conclusions:

• Findings support neurodevelopmental abnormalities in visual processing pathways in Williams syndrome.
• Results implicate extended subcortical and cortical visual systems, particularly dorsal-stream pathways, in WS.
• The study confirms previous research and neural models of visual integration deficits in WS.