Ronga I, Sarasso P, Raineri F, Duhamel J-R, Becchio C, Neppi-Modona M
SAMBA (SpAtial, Motor & Bodily Awareness) Research Group, Department of Psychology, University of Turin, Via Po, 14, 10123, Torino, Italy.
Institut des Sciences Cognitives Marc Jeannerod, CNRS, Bron, Lyon, France.
Exp Brain Res. 2017 Jun;235(6):1759-1770. doi: 10.1007/s00221-017-4934-3. Epub 2017 Mar 11.
Wedge prisms shifting the visual field laterally create a mismatch between the straight ahead position signalled by vision and that encoded by extraretinal and head-on-trunk proprioceptive information. Short-term adaptation to left-deviating prisms in normal subjects results in a visuomotor attentional bias towards the right-hand side (aftereffect). Prismatic adaptation (PA) is usually induced through a training consisting in repeated ballistic movements of the dominant arm towards visual targets, while participants are wearing prismatic goggles. The present study demonstrates that an original oculomotor PA procedure with leftward deviating prisms-without pointing movements and only consisting in repeated gaze shifts towards visual targets-can induce a rightward bias in normal subjects as assessed by visual straight ahead and line bisection tasks (Experiments 1 and 2). We show that oculomotor PA induces a bias in line bisection similar to that reported after visuomotor PA (Experiment 2). We suggest that a conflict between retinal, extraretinal and proprioceptive information about the straight ahead location causes the observed effects. In follow-up experiments 3, 4, and 5, we demonstrate that neither eye deviation without prisms nor shift of the visual field without eye deviation induces PA biases. We propose that an optimal integration model of visual and proprioceptive inputs can best account for the observed results.
向外侧移动视野的楔形棱镜会在视觉所信号的正前方位置与视网膜外和头部与躯干本体感受信息所编码的正前方位置之间造成不匹配。正常受试者对向左偏斜棱镜的短期适应会导致视觉运动注意力偏向右侧（后效应）。棱镜适应（PA）通常是通过一种训练来诱发的，即让受试者戴着棱镜护目镜，同时优势手臂朝着视觉目标进行重复的弹道式运动。本研究表明，一种使用向左偏斜棱镜的原始动眼神经PA程序——无需指向动作，仅包括朝着视觉目标的重复注视转移——在通过视觉正前方和直线二等分任务评估时，可在正常受试者中诱发向右的偏向（实验1和2）。我们表明，动眼神经PA在直线二等分中诱发的偏向与视觉运动PA后所报告的偏向相似（实验2）。我们认为，关于正前方位置的视网膜、视网膜外和本体感受信息之间的冲突导致了所观察到的效应。在后续的实验3、4和5中，我们证明，无棱镜时的眼偏斜和无眼偏斜时的视野转移均不会诱发PA偏向。我们提出，视觉和本体感受输入的最佳整合模型能够最好地解释所观察到的结果。
