Attentional rather than sensory differences characterize auditory processing in Williams syndrome.

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Developmental Neuroscience

Background:

• Individuals with Williams Syndrome (WS) often display atypical sensory processing, particularly in the auditory domain.
• Previous research suggests potential differences in auditory perception, but detailed electrophysiological evidence is limited.

Purpose of the Study:

• To investigate early sensory and later cognitive stages of auditory cortical processing in adults with Williams Syndrome (WS) using event-related potentials (ERPs).
• To compare auditory processing between adults with WS and age-matched typical peers using an auditory oddball task.

Main Methods:

• Two experiments employed a three-stimulus auditory oddball task with event-related potentials (ERPs) to measure cortical auditory processing.
• Stimuli included piano chords (Study 1) and varied non-piano sounds (Study 2) as standard, target, and novel sounds.
• Measured early sensory ERPs (P1, N1, P2) and later cognitive ERPs (P3a, P3b) in participants with WS and controls.

Main Results:

• No significant group differences were observed in early sensory ERPs (P1, N1).
• Participants with WS showed larger P2 responses, indicating atypical early sensory encoding.
• Williams Syndrome participants exhibited larger P3a responses when novel stimuli were perceptually distinct, but not when stimuli were similar.
• A reduced P3b response in the WS group suggested diminished goal-directed attention.

Conclusions:

• Auditory processing in Williams Syndrome is more complex than previously thought, with differences emerging in later cognitive stages.
• Group differences in ERPs were not correlated with IQ, highlighting a specific neurodevelopmental profile in WS.
• Findings suggest atypical stimulus categorization and evaluation, but not early sensory detection, in individuals with Williams Syndrome.