Templates and temporality: an investigation of rhythmic motor production in a young man with Down Syndrome and hearing impairment

The musical rhythmic abilities of people with Down Syndrome (DS) reportedly exceed their general cognitive abilities. Although they display atypical rhythmic production in musical motor tasks, little is known about how their developmental and cognitive differences affect temporal perception or production. Additionally, hearing impairment often excludes potential participants from studies, further limiting our understanding. This case study examined the rhythmic ability of one young adult with DS and moderate-severe hearing impairment when producing limb-motor movements to music in auditory-only and auditory-visual conditions. His temporal accuracy was observed for gross-motor movements to music. Measurements were made of his temporal accuracy and stability when tapping on a drum at three tempi, and when tapping to non-isochronous rhythms. Results revealed temporal deficits in all tasks. However, production improved in tasks that were augmented with visuo-spatial stimuli, and in isochronous beat entrainment at the fastest tempo. Findings were compared to the participant’s cognitive and perceptual profile. Results suggest that his production was limited by developmental factors, but that auditory memory deficits and hearing may account for instability in isochronous entrainment tasks and delayed onset of timing. Recommendations are made for supporting skills in production and perception of auditory rhythms within the DS population.