MySpace Lab, Department of Clinical Neurosciences, Lausanne University Hospital (CHUV) and University of Lausanne, Avenue Pierre Decker 5, 1011 Lausanne, Switzerland.
Center of Advanced Technologies in Rehabilitation (CATR), Sheba Medical Center, Tel Hashomer 52621, Israel.
Cereb Cortex. 2023 Apr 25;33(9):5163-5180. doi: 10.1093/cercor/bhac407.
Our everyday life summons numerous novel sensorimotor experiences, to which our brain needs to adapt in order to function properly. However, tracking plasticity of naturalistic behavior and associated brain modulations is challenging. Here, we tackled this question implementing a prism adaptation-like training in virtual reality (VRPA) in combination with functional neuroimaging. Three groups of healthy participants (N = 45) underwent VRPA (with a shift either to the left/right side, or with no shift), and performed functional magnetic resonance imaging (fMRI) sessions before and after training. To capture modulations in free-flowing, task-free brain activity, the fMRI sessions included resting-state and free-viewing of naturalistic videos. We found significant decreases in spontaneous functional connectivity between attentional and default mode (DMN)/fronto-parietal networks, only for the adaptation groups, more pronouncedly in the hemisphere contralateral to the induced shift. In addition, VRPA was found to bias visual responses to naturalistic videos: Following rightward adaptation, we found upregulation of visual response in an area in the parieto-occipital sulcus (POS) only in the right hemisphere. Notably, the extent of POS upregulation correlated with the size of the VRPA-induced after-effect measured in behavioral tests. This study demonstrates that a brief VRPA exposure can change large-scale cortical connectivity and correspondingly bias visual responses to naturalistic sensory inputs.
我们的日常生活中会涌现出许多新颖的感觉运动体验，大脑需要适应这些体验才能正常运作。然而，跟踪自然行为的可塑性及其相关的大脑调制是具有挑战性的。在这里，我们通过虚拟现实中的棱镜适应样训练（VRPA）结合功能神经影像学来解决这个问题。三组健康参与者（N=45）接受了 VRPA（向左/右侧移动，或不移动），并在训练前后进行了功能磁共振成像（fMRI）扫描。为了捕捉自由流动、无任务的大脑活动中的调制，fMRI 扫描包括静息状态和自然视频的自由观看。我们发现，仅在适应组中，注意力和默认模式（DMN）/额顶叶网络之间的自发功能连接显著降低，在诱导移位的对侧半球更为明显。此外，VRPA 被发现偏向于对自然视频的视觉反应：在向右适应后，我们仅在右半球发现了顶枕沟（POS）中一个区域的视觉反应上调。值得注意的是，POS 上调的程度与行为测试中测量到的 VRPA 诱导的后效大小相关。这项研究表明，短暂的 VRPA 暴露可以改变大脑的大范围连接，并相应地偏向于对自然感觉输入的视觉反应。
