Altered Arm-Body Coordination with Triggered Pointing Responses as Influenced by Task Predictability. Issue 2 (3rd March 2020)

• Record Type: Journal Article
• Authors: Prout, Erik C.; Huntley, Andrew H.; Zettel, John L.
• Is Part Of: Journal of motor behavior. Volume 52:Issue 2(2020)
• Page Start: 131
• Page End: 144
• Publication Date: 2020-03-03
• Subjects: Balance -- postural control -- triggered arm reactions -- double-step pointing.; Human mechanics -- Periodicals; Movement, Psychology of -- Periodicals; Motor Activity -- Periodicals; Motor Skills -- Periodicals; Bewegingsleer; Mécanique humaine -- Périodiques; Psychomotricité -- Périodiques; 612.705
• DOI: 10.1080/00222895.2019.1596874
• Languages: English
• ISSNs: 0022-2895

Abstract

Abstract: Reaching movements generate reaction forces that affect postural stability, requiring sophisticated coordination between body and arm movement to maintain balance. In voluntary movement, this coordination involves feedforward shifts of posture, and such anticipatory postural muscle activity also accompanies the rapid modulation of an ongoing point to suddenly a shifting target (double-step). However, it is unknown if this early postural activity depends on target-shift predictability and whether arm and body motion are similar coordinated to voluntary movement. Body and arm motion coordination during double-step pointing movements from standing were done under differing conditions of target-shift predictability. In a proportion of trials, the pointing target was displaced, with the predictability of target-shift direction varied between two peripheral targets (target-shift direction known) and two central targets (target-shift direction uncertain). The target jump evoked an adjustment in the arm then body response, opposite to the pointing responses to the initial target. The triggered arm-then-body ordering was consistent across target-shift predictability, although known target-shift direction resulted in closer timing of arm and body onsets. The altered coordination in triggered corrections suggests that the body component in triggered reactions depend on response predictability, showing an altered control of arm and body motion.