Morphological differences in the mirror neuron system in Williams syndrome

Area of Science:

• Neuroscience
• Genetics
• Developmental Psychology

Background:

• Williams syndrome (WS) is a genetic disorder with distinct social behaviors, including high gregariousness and empathy.
• Both WS and autism spectrum disorder (ASD) exhibit social communication and cognition deficits.
• The mirror neuron system (MNS) is implicated in ASD social dysfunction, but its role in WS is unexplored.

Purpose of the Study:

• To investigate the structural integrity of the MNS in adults with WS compared to typically developing (TD) individuals.
• To examine the relationship between MNS morphology and social functioning in WS.

Main Methods:

• Magnetic resonance imaging (MRI) was used to analyze MNS structural integrity.
• The Social Responsiveness Scale (SRS) assessed social functioning in WS participants.

Main Results:

• WS individuals displayed reduced MNS cortical surface area but preserved cortical thickness compared to TD adults.
• Increased inferior parietal lobule (IPL) cortical thickness correlated with greater social communication, awareness, and cognition deficits, and autistic mannerisms in WS.
• Social motivation in WS was not associated with MNS anatomical features.

Conclusions:

• Aberrant MNS structure may underlie shared social deficits in WS and ASD.
• Distinct neural substrates likely support the pronounced social drive observed in WS, separate from the MNS.