Steinl S M, Johannsen L
Department of Sport and Health Science, Technical University Munich, Munich, Germany.
Department of Sport and Health Science, Technical University Munich, Munich, Germany; School of Health Sciences, University of East Anglia, Norwich, United Kingdom.
Gait Posture. 2017 Mar;53:17-24. doi: 10.1016/j.gaitpost.2016.12.029. Epub 2016 Dec 30.
Caregiver-patient interactions rely on interpersonal coordination (IPC) involving the haptic and visual modalities. We investigated in healthy individuals spontaneous IPC during joint maximum forward reaching. A 'contact-provider' (CP; n=2) kept light interpersonal touch (IPT) laterally with the wrist of the extended arm of a forward reaching, blind-folded 'contact-receiver' (CR; n=22). Due to the stance configuration, CP was intrinsically more stable. CR received haptic feedback during forward reaching in two ways: (1) presence of a light object (OBT) at the fingertips, (2) provision of IPT. CP delivered IPT with or without vision or tracked manually with vision but without IPT. CR's variabilities of Centre-of-Pressure velocity (CoP) and wrist velocity, interpersonal cross-correlations and time lags served as outcome variables. OBT presence increased CR's reaching amplitude and reduced postural variability in the reach end-state. CR's variability was lowest when CP applied IPT without vision. OBT decreased the strength of IPC. Correlation time lags indicated that CP retained a predominantly reactive mode with CR taking the lead. When CP had no vision, presumably preventing an effect of visual dominance, OBT presence made a qualitative difference: with OBT absent, CP was leading CR. This observation might indicate a switch in CR's coordinative strategy by attending mainly to CP's haptic 'anchor'. Our paradigm implies that in clinical settings the sensorimotor states of both interacting partners need to be considered. We speculate that haptic guidance by a caregiver is more effective when IPT resembles the only link between both partners.
照顾者与患者的互动依赖于涉及触觉和视觉模式的人际协调（IPC）。我们在健康个体中研究了联合最大前伸过程中的自发IPC。一名“接触提供者”（CP；n = 2）与一名前伸且蒙眼的“接触接受者”（CR；n = 22）伸出的手臂手腕保持轻微的人际接触（IPT）。由于姿势配置，CP本质上更稳定。CR在前伸过程中通过两种方式接收触觉反馈：（1）指尖处有一个轻物体（OBT），（2）提供IPT。CP在有视觉或无视觉的情况下提供IPT，或者在有视觉的情况下手动跟踪但不提供IPT。CR的压力中心速度（CoP）和手腕速度的变异性、人际交叉相关性和时间滞后作为结果变量。OBT的存在增加了CR的前伸幅度，并降低了前伸终末状态下的姿势变异性。当CP在无视觉的情况下应用IPT时，CR的变异性最低。OBT降低了IPC的强度。相关时间滞后表明CP主要保持反应模式，CR起主导作用。当CP没有视觉时，可能会阻止视觉优势的影响，OBT的存在产生了质的差异：在没有OBT的情况下，CP引领CR。这一观察结果可能表明CR通过主要关注CP的触觉“锚点”而改变了协调策略。我们的范式意味着在临床环境中需要考虑两个互动伙伴的感觉运动状态。我们推测，当IPT类似于两个伙伴之间的唯一联系时，照顾者的触觉引导更有效。
