The purpose of this experiment is to investigate thefine motor performance of young and older adults on
a reach to grasp task in a desktop virtual environment with increasing precision requirements. Aging
brings about potential loss of an individual
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s function due to disease, injury, or the degenerative nature of
aging itself. Three-dimensional virtual environments have been identified as systems with good potential
to ameliorate such problems in older individuals, and precise fine motor skills represent an important
class of functional skills. Two groups of participants (Young,n¼10, mean age 21.3 years, range 20–24,
senior, n¼10, mean age 70.7 years, range 60–85) performed a reach to grasp in a desktop virtual
environment with simple, low contrast graphics. Results indicate that visual feedback of the hand for
sensory guidance of movement did not improve motor performance for either group, and that as
precision requirements of the task increased, age group differences in movement time and peak grasp
aperture also increased. Thesefindings extend the literature on age group differences in human motor
control across the lifespan and differ from previous studies which showed presence of visual feedback of
the hand improved motor performance in young adults. Differences in luminance contrast levels in past
studies and the current one suggest that control over this feature of the visual scene is an important
design consideration for all end-users and warrants additional investigation. Additional recommenda-tions for age-specific design of three dimensional user interfaces include usage of tangibles that are
sufficient in size to limit detrimental effects for older adults.