the effect of sensory feedback on the transition of the relative phase in bimanual coordination task in old adults

abstract   introduction: the purpose of present research was the study of the effect of sensory feedback on speed of the relative phase transition in anti-phase bimanual coordination pattern across old adults. materials and methods: therefore 15 intact male old adults selected in available with age range 60-70 years that were all of them hand-right. participants started their movement on bimanual coordination device with anti-phase at frequency 0/75 hz and was increased to it 0/25 hz by step 5 seconds and final frequency was 5 hz. present task performed under 8 sensory conditions. for investigating data used repeated measures analysis of variance 2×2×2 and paired-samples t-test with bonferroni correction for pair comparisons of the interaction effects. results: the findings revealed that main effects of proprioception (p=0/001), audition (p=0/001) and two-way interaction (p=0/022) were significant.these results implied to positive effects of audition and proprioception feedback and also more effect of exist of audition information along with lack of vision onthe speed of relative phase transition. conclusion: the findings reflected that the performance of present bimanual coordination task was under close-loop control system. also the results reflect the role of control parameter in performing coordinated movement and relative phase transition from one inconsistence pattern to another more consistence pattern as movement speed increased. with regard to older adults revealed more impairments in audition and proprioception than vision condition and also more variability and the speed of the phase transition, we could conclude thatthese population relied on audition and proprioception to perform bimanual coordination patterns.