Influence of age on left-hand grasping in different behavioral contexts

Our group recently introduced a paradigm for comparing the execution of grasping movements
with the same physical constraints in two different behavioral contexts, once as a
typical laboratory task and once as an everyday-like task. We found that movement kinematics
differed substantially between contexts, and the differences were reduced by factor
analysis to five orthogonal components. The context difference was even larger in elderly
participants; here we investigate if this holds even if the left (non-dominant) hand is used
for grasping. We found that with the left hand, context-dependence of grasping still existed
but was no longer larger in old age. Factor analysis again traced the context-dependence
back to multiple orthogonal factors.
We suggest that young subjects possibly improve their left-hand performance in the laboratory
context by devoting substantial attention to the task; this strategy is not available in
the everyday context, which increases the context dependence of that age group.