Is mild intellectual disability associated with a rhythmic skills impairment? A developmental perspective

BACKGROUND: While rhythm is an essential component of human development that contributes to both cognitive abilities and interactive behaviors, to date, research on rhythmic skills in individuals with mild intellectual disability (MID) - whose intellectual and adaptive functioning is impaired - is almost non-existent. If rhythmic abilities were deficient in these individuals, they could constitute a factor limiting their social integration and autonomy in daily life, that clinicians cannot neglect in their support. AIMS: The aim of our study was to better understand rhythm perception and production abilities and their development between 10 and 15 years and 16-21 years in individuals with idiopathic MID, compared to typically developing (TD) individuals. METHODS AND PROCEDURES: Fifty-seven MID and sixty-eight TD participants matched on chronological age were tested in a rhythm discrimination task and a rhythm production task, including two spontaneous motor tempo (SMT) recording and a synchronization-continuation phase in which they had to produce rhythms that were identical, slower or faster than their own SMT, and this with three different response modalities. OUTCOMES AND RESULTS: Participants with MID performed worse than TD participants on all rhythmic tasks, while exhibiting a faster and more unstable SMT. CONCLUSIONS AND IMPLICATIONS: These findings suggest the existence of a deficit in both rhythmic perception and production skills in individuals with MID, compared to TD individuals. Our study thus helps to demonstrate the importance of a standardized assessment of rhythmic abilities and the role of these abilities in rehabilitation protocols for patients.