The influence of proprioception of limb-target processes


When moving one's limb to a target, it has been hypothesized that separate online correction processes take place, including impulse regulation and limb-target processes (Elliott et al. 2010). It has also been suggested that vision for the use of limb-target processes is optimized when the limb reaches 1.0 m/s (Tremblay et al., 2013). However, proprioception is another potential source of information that could be useful for limb-target regulation. Participants completed two blocks of trials wherein agonist-antagonist tendon vibration was applied between trials at the elbow joint. This manipulation was employed to decrease the sensitivity of the muscle spindles of the elbow joint during the interspersed movements. During both blocks of trials, participants were provided with 20 ms windows of vision when their moving limb reached either 0.6, 1.0, or 1.4 m/s while reaching to a 30 cm target. On a third of the trials, a "jumped" target (i.e., 27 cm) replaced the 30 cm target during the window. In the absence of vibration, target jumps yielded significant shifts in endpoint distributions for the 0.6 and 1.0 m/s windows. In contrast, shifts in endpoint distributions were significant in all window conditions in the vibration block. However, the times after peak velocity were longer during the vibration block, as compared to the no vibration block. These results reveal that proprioception is important for the optimization of limb-target regulation processes.

Acknowledgments: NSERC, CFI, Ontario Research Fund