Shannon D. Ringenbach, Romeo Chua, Brian K. V. Maraj, James C. Kao and Daniel J. Weeks
Previous experiments involving discrete unimanual tasks have shown that individuals with Down syndrome (DS) have auditory/verbal-motor deficits. The present study investigated unimanual and bimanual continuous perceptual-motor actions in adults with DS. Ten adults with DS, 10 typical adults, and 10 children drew continuous circles at increasing periods bimanually and unimanually with each hand. Movement was paced by either a visual or an auditory metronome. The results revealed that for circle shape and coordination measures, children and adults were more accurate with the visual metronome, whereas adults with DS were more accurate with the auditory metronome. In the unimanual tasks, adults with DS displayed hand asymmetries on spatial measures. In the bimanual task, however, adults with DS adopted an in-phase coordination pattern and stability more similar to adults than children. These results suggest that bimanual coordination in adults with DS is functioning effectively despite hand asymmetries evident in unimanual performance.
Shannon D.R. Ringenbach, Kristina Zimmerman, Chih Chia Chen, Genna M. Mulvey, Simon D. Holzapfel, Daniel J. Weeks and Michael H. Thaut
The present study used a synchronization-continuation paradigm during continuous bimanual drumming with different cues in 17 persons with Down syndrome, eight typical persons with similar mental age and eight typical persons with similar chronological age. The task required participants to hit two drums with their hands at the same time following music (e.g., a tune with various decibel drum beats), auditory (e.g., sound of drumbeat), verbal (e.g., voice saying “drum”), and visual (e.g., video of both hands moving up and down and hitting the drums together) cues for 10 seconds, then continue drumming in the absence of cues for another 10 seconds. In general, when all groups were following the music cues their movements were faster as compared with their movements in the auditory, verbal, and visual conditions. In addition, when following visual cues all groups produced more accurate and consistently coordinated movements than with the other cue types. Further, participants with Down syndrome often stopped moving when the pacing cues were eliminated indicating a need for continuous cues for continuous movements.