Résumé
The one-target advantage (OTA), in which participants perform single-target reaching movements faster compared to two-target sequential movements, is well-established in younger adults. Older adults, however, adjust their aiming movements to account for age-related changes in sensory and motor systems. Recently, we demonstrated that older adults exhibit the OTA and that vibrotactile feedback improves two-target aiming performance. The present study extends this research by examining if auditory (A) or vibrotactile (VT) feedback affects planning and execution of various bimanual OTA tasks. Twenty-four older adults (Aged 60-82 years) performed 5 target tasks under 3 feedback conditions: no feedback (NF), (A), and (VT). Position data were captured via an Optotrak 3D motion-tracker and analyzed using repeated measures ANOVAs. Reaction time (RT) was significantly influenced by task complexity (F4,92=10.83, p=.001), with the shortest RT in the two-target extension with single hand 2T1He condition. A significant Feedback × Task interaction (F8, 184 = 2.92p=.004), showed that VT reduced RT in 2T1He compared to all other conditions.Movement time to the second target increased with task complexity (F3,69=26.81, p=.001),especially in bimanual reversal tasks. Kinematic analyses revealed that VT increased peak velocity (PV2) and shortened time after PV(TAPV2).Notably, time to PV in the second sequential movement (TTPV2) was prolonged with VT in complex sequences (F6,138=3.57, p=.003), implying strategic modulation of acceleration under increased task demands. These findings suggest VT feedback enhances older adult movement planning and execution, particularly under moderate task demands, demonstrating promise for improving sensorimotor function during sequential movements.
