The influence of neck muscle vibration and background information on limb position across the movement trajectory during upper limb pointing


When making reaching movements towards a target, humans utilize sensory stimuli arising from the body and the environment. Manipulating proprioceptive cues (e.g., neck muscle vibration; Roll et al., 1991) and manipulating background cues (e.g., dots between the home and target positions; Coello & Magne, 2000) have both been independently shown to influence endpoint position during target aiming. Also, according to the multiple-process model, online limb control occurs first through early impulse regulation and then through limb-target regulation processes, relying on proprioceptive information of the limb and vision of the target (Elliott et al., 2010). The experimental purpose was to investigate the separate and combined influence of neck proprioception (i.e., egocentric cues) and visual background (i.e., allocentric cues) on these online control processes. Seventeen participants (9 male; Mage = 24.4 ± 3.6 y/o) performed reaching movements towards a target while posterior neck muscle vibration and a white dot grid background were manipulated. The key variables of interest were the limb positions at 25%, 50%, 75% and 100% of movement time. Vibration led to lower limb height and greater leftward trajectories after 50% of the movement while background information led to significantly farther limb position throughout the trajectory (i.e., from 25% onwards). However, no significant vibration x background interactions were found. Thus, neck proprioception influenced the later stage of the trajectories while background information influenced the earlier stage, lending further support to independent and distinct phases of online control of Elliott et al. (2010).

Acknowledgments: NSERC