A virtual reality-based system integrated with fmri to study neural mechanisms of action observation-execution: a proof of concept study.
A virtual reality-based system integrated with fmri to study neural mechanisms of action observation-execution: a proof of concept study.
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DOI：
10.3233/rnn-2009-0471
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发表时间：
2009
影响因子：
2.8
通讯作者：
Tunik E
中科院分区：
文献类型：
--
作者：
Adamovich SV;August K;Merians A;Tunik E
新出现的证据表明，交互式虚拟环境(VES)可能是研究感觉运动过程和康复的一种很有前途的工具。然而，VES招募动作观察-执行神经网络的潜力在很大程度上是未知的。首次开发了与功能磁共振兼容的虚拟现实系统(VR)，为研究大脑与行为的相互作用提供了一个窗口。该系统能够测量手-手指运动的复杂跨度，并同时传输这些运动学数据来控制虚拟现实中手部表示的运动。在模块化的功能磁共振成像设计中，13名健康受试者为了模仿(OTI)，观察了虚拟手化身在第一人称视角下执行的手指序列，并通过预先记录的运动学数据进行了动画制作。随后，受试者模仿观察到的序列，同时实时观看由他们自己的运动生成的虚拟手的化身。这些区块与休息期交错，在此期间，受试者观看静态虚拟手的化身，而对照试验中，化身被移动的非拟人化物体取代。我们展示了三个主要发现。首先，意图模仿的观察和具有实时虚拟化身反馈的模仿都与分布式额顶网络中的激活有关，通常被招募用于观察和执行现实世界的动作。其次，我们注意到左侧岛叶皮质的激活随时间而增加，以进行观察，目的是模仿虚拟化身执行的动作。第三，具有虚拟化身反馈的模仿(相对于控制条件)与角回、楔前核和纹状体外区域的局部招募有关，这些区域(以及岛叶皮质)与代理感相关。我们的数据表明，虚拟手的化身可能在观察条件下充当了非实体的训练工具，并在模仿中作为受试者自身身体(伪工具)的具体化“延伸”。这些数据促进了我们对在VE中执行动作时大脑-行为交互作用的理解，并对基于观察和模仿的VR康复范式的发展具有启示意义。
Emerging evidence shows that interactive virtual environments (VEs) may be a promising tool for studying sensorimotor processes and for rehabilitation. However, the potential of VEs to recruit action observation-execution neural networks is largely unknown. For the first time, a functional MRI-compatible virtual reality system (VR) has been developed to provide a window into studying brain-behavior interactions. This system is capable of measuring the complex span of hand-finger movements and simultaneously streaming this kinematic data to control the motion of representations of human hands in virtual reality. In a blocked fMRI design, thirteen healthy subjects observed, with the intent to imitate (OTI), finger sequences performed by the virtual hand avatar seen in 1st person perspective and animated by pre-recorded kinematic data. Following this, subjects imitated the observed sequence while viewing the virtual hand avatar animated by their own movement in real-time. These blocks were interleaved with rest periods during which subjects viewed static virtual hand avatars and control trials in which the avatars were replaced with moving non-anthropomorphic objects. We show three main findings. First, both observation with intent to imitate and imitation with real-time virtual avatar feedback, were associated with activation in a distributed frontoparietal network typically recruited for observation and execution of real-world actions. Second, we noted a time-variant increase in activation in the left insular cortex for observation with intent to imitate actions performed by the virtual avatar. Third, imitation with virtual avatar feedback (relative to the control condition) was associated with a localized recruitment of the angular gyrus, precuneus, and extrastriate body area, regions which are (along with insular cortex) associated with the sense of agency. Our data suggest that the virtual hand avatars may have served as disembodied training tools in the observation condition and as embodied “extensions” of the subject’s own body (pseudo-tools) in the imitation. These data advance our understanding of the brain-behavior interactions when performing actions in VE and have implications in the development of observation- and imitation-based VR rehabilitation paradigms.