Age-related Differences In Control Research Articles

Age-related differences in control of a visuomotor coordination task: a preliminary study

[Purpose] The purpose of the current study was to examine age-related differences in control of a perception-action coordination skill. We adapted a visuomotor tracking experiment requiring various coordination patterns between a limb’s motion and an external signal. [Subjects and Methods] A total of 12 subjects (6 elderly and 6 young) voluntarily participated in the study. The experimental session consisted of 3 trials for 3 different relative phase patterns: 0°, 90°, and 180°, defined by the relationship between the online visual feedback of the joystick motion and the white dot signal. [Results] The 0° and 180° tracking patterns were stable compared with the 90° tracking pattern for both age groups. The present results also showed that the elderly subjects were less stable than were young subjects for all tracking patterns. [Conclusion] The intrinsic coordination dynamics predicted by the Haken-Kelso-Bunz (HKB) mathematical model did not change with age, whereas utilization of visual feedback information declined overall. Further research is needed regarding methods for increasing utilization of visual feedback information from the perspective of rehabilitation.

Age-related differences in force variability and visual display

It is well established that older adults are more variable in their force output and that this age-related decrement is mediated by visuomotor processing. The purpose of this investigation was to examine whether the type of visual display impacts age-related differences in the control of force output. In order to address this question, young and old participants produced constant isometric force via index finger abduction to 3 force levels [5, 10, and 20% of their maximal voluntary contraction (MVC)]. Visual feedback was presented with either a compensatory or a pursuit display. A compensatory display provides visual feedback about force amplitude in relation to the criterion target whereas a pursuit display provides visual feedback about the force trajectory in relation to the criterion target and preview of the target path of the force trajectory. The magnitude of force variability was indexed with standard deviation and coefficient of variation. The structure of force output was indexed with spectral slope and approximate entropy. As expected, older adults were more variable and had more structured force output compared to younger adults. Moreover, this age-related difference in force control was paramount in pursuit displays. Overall, the findings suggest that age-related differences in force control are centrally mediated. It is proposed that older adults have deficits in visuomotor processing and this may be partly related to age-related decrements in the control of eye movements.

Age-Related Differences in Control Processes in Verbal and Visuospatial Working Memory: Storage, Transformation, Supervision, and Coordination

We explored age differences in transformation, supervision, and coordination processes in verbal and visuospatial repetition-detection tasks. Older adults processed information more slowly and less accurately than did younger adults, especially in the visuospatial task. However, there were no process-specific age-related differences in the visuospatial domain. In the verbal domain, task conditions requiring supervision and coordination showed larger age effects than the baseline or transformation conditions. Taken together, the findings provide support for a process- and domain-specific account of age-related differences in cognitive control, which may be tied to an age-related deficit in the maintenance of two separate sets of representations.