Exploring the time-course and the reference frames of adaptation to optical prisms and its aftereffects
Exploring the time-course and the reference frames of adaptation to optical prisms and its aftereffects
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探索光学棱镜适应的时间过程和参考系及其后果
DOI：
10.1016/j.cortex.2021.04.002
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发表时间：
2021
期刊：
影响因子：
3.6
通讯作者：
G. Vallar
中科院分区：
文献类型：
--
作者：
Stefano Terruzzi;D. Crivelli;E. Campana;A. Pisoni;L. R. Romero Lauro;N. Bolognini;G. Vallar
棱镜适应（PA）用于研究视觉运动可塑性并康复单侧空间忽视（USN）综合征。PA后，参与者显示后效（AE），对侧的光学位移在几个任务。本研究探讨了这些不良事件的特征，特别是“自我中心”与“以他人为中心，以对象为基础”，涉及的参考框架，以及它们的时间过程。在三个实验中，健康的参与者适应棱镜镜片诱导视野的水平位移。在实验#1中，参与者适应了移动棱镜。使用了四个任务，需要重复指向参与者的主观自我中心的直线前进，具有本体感受或视觉本体感受信号的可用性，并且在某些情况下，具有外部的非自我中心视觉框架（即，矩形纸张）。实验#2探索了位置的allocentric框架的作用，与AE进行测试的直线前进和帧平分任务，需要指向外部的视觉框架，放置在不同的位置的工作空间。在棱镜移除后和执行非自我中心任务后，进行自我中心视觉本体感受任务，以评估PA的有效性（根据AE指数）及其持续性（直至非自我中心任务给药结束）。实验#3与实验#2的不同之处在于参与者适应了非置换镜片。与来自USN患者的证据一致，在实验#1中，在自我中心任务中，发现PA后持续长达30分钟的AE。在实验#2中，无论帧位置如何，“非自我中心”任务中均未发生AE。实验#3在“自我中心”和“非自我中心”任务中都显示出AE，后者的大小较小。这些研究结果表明，PA调制的空间参考系统在个人以外的空间主要是在空间的“自我中心”的参考框架，与一个相对较小的和特定方向的“allocentric”框架的作用。
Prism adaptation (PA) is used to investigate visuo-motor plasticity and to rehabilitate the syndrome of Unilateral Spatial Neglect (USN). After PA, participants show aftereffects (AEs), contralateral to the side of the optical displacement in several tasks. This study explored the features of these AEs, specifically the “egocentric” versus “allocentric, object-based”, reference frames involved, and their time course. In three experiments, healthy participants adapted to prismatic lenses inducing a horizontal displacement of the visual field. In Experiment #1, participants adapted to rightward displacing prisms. Four tasks were used requiring repeated pointings towards the participant's subjective egocentric straight-ahead, with the availability of proprioceptive or visual-proprioceptive signals, and, in some conditions, of an external allocentric visual frame (i.e., a rectangular paper sheet). Experiment #2 explored the role of the position of the allocentric frame, with AEs being tested by straight-ahead and frame bisection tasks, requiring pointing toward the external visual frame, placed in different positions of the working space. An egocentric visual proprioceptive task was administered after prism removal and after the execution of the allocentric tasks, to assess the effectiveness of the PA, as indexed by the AEs, and their persistence up to the end of the administration of the allocentric tasks. Experiment #3 differed from #2 in that participants adapted to leftward displacing lenses. Consistent with evidence from USN patients, in Experiment #1, in the egocentric tasks, AEs lasting up to 30 min after PA were found. In Experiment #2, AEs in “allocentric” tasks did not occur, regardless of frame position. Experiment #3 showed AEs in both the “egocentric” and the “allocentric” tasks, with the latter being minor in size. These findings illustrate that the spatial reference systems modulated by PA in extra-personal space primarily operate in spatial “egocentric” reference frames, with a comparatively minor and direction-specific role of “allocentric” frames.