Doctor of Philosophy (PhD)
Spatial coordination of bimanual movements is important when performing daily activities. Whereas, older adults and individuals with Parkinson’s disease (PD) commonly show difficulties in temporally coordinating the hands in bimanual coordination tasks, the effects of aging and Parkinson’s disease on the quality of spatial coordination between the hands are unclear. Thus, the present work investigated the impact of older age and PD on the spatial interference in a bimanual task in which 48 right hand-dominant participants (16 young adults, 16 older adults and 16 individuals with PD) drew simultaneously two lines with both hands with varied movement amplitudes (3 and 6 cm) and/or directions (horizontal and vertical). The dependent variables were amplitude error of the line drawn with the right hand (A-error-R), amplitude error of the line drawn with the left hand (A-error-L), directional error of the line drawn with the right hand (D-error-R) and directional error of the line drawn with the left hand (D-error-L). The results showed that older adults were able to maintain a similar level of spatial accuracy on the dominant side as young adults, but they showed reduced spatial accuracy when using the non-dominant hand. Furthermore, advanced age altered the control of movement direction in the bimanual coordination task, but not the control of movement amplitude. These results indicate that, the effects of the use of a longer standard spatial code for movement amplitude did not change in older adults, but older age does alter the control of direction in bimanual movements. Individuals with Parkinson’s disease and older adults showed similar levels of spatial accuracy, except for the directional accuracy of the lines drawn with the dominant hand; these lines showed angles with the target direction were increased about two degree in the PD group as compared to older control group. In summary, the quality of spatial coordination declined only in part in older adults, and the decline in the quality of spatial coordination was not exacerbated in individuals with PD, indicating the divergent role of basal ganglia for the control of temporal and spatial aspects.
Document Availability at the Time of Submission
Release the entire work immediately for access worldwide.
Pan, Zhujun, "The Control of Amplitude and Direction in Bimanual Coordination" (2014). LSU Doctoral Dissertations. 3673.
Van Gemmert, Arend