A Tactile Virtual Reality for the Study of Active Somatosensation
A Tactile Virtual Reality for the Study of Active Somatosensation
复制标题
DOI：
10.3389/fnint.2020.00005
复制
发表时间：
2020-02-18
影响因子：
3.5
通讯作者：
Braun, Christoph
中科院分区：
文献类型：
--
作者：
Bhattacharjee, Arindam;Kajal, Diljit Singh;Braun, Christoph
纹理的自然探索涉及主动传感，即，触觉传感器的自主运动（例如，人的指尖或啮齿动物的胡须）穿过目标表面。在移动触觉传感器期间的体感输入根据移动和表面纹理两者而变化。结合运动和感觉信息，大脑能够提取被探索表面的纹理特征。尽管主动感知的生态相关性，心理物理学研究主动触摸在很大程度上是失踪。缺乏研究主动触摸的信息性研究的一个原因是组装适当的实验装置的相当大的挑战。一个可能的解决方案可能是虚拟触觉现实领域，它根据手的位置和目标表面的模拟纹理提供触觉手指刺激。除了严格的行为研究，在人类中的主动触觉传感的神经元机制的调查是非常必要的，需要使用脑电图（EEG），脑磁图（MEG）和/或功能磁共振成像（fMRI）的神经生理学实验。然而，当前的神经成像技术在与所使用的神经生理学方法的兼容性方面对触觉刺激递送设备强加了特定要求。在这里，我们提出了一个用户友好的，MEG兼容，触觉虚拟现实模拟器。该模拟器由压电触觉刺激器组成，能够独立地突出16个以4 × 4矩阵排列的直径为1 mm的塑料活塞。刺激器根据手指在2维平面上移动的位置向手指的指尖递送触觉刺激的空间图案。为了展示触觉虚拟现实的功能，我们确定了参与者在主动和被动触摸条件下的检测阈值。在这两种条件下的保留时间均高于文献中的报告。很可能是活塞相关刺激的处理被将手指放在扫描探针上产生的感觉输入所掩盖。更重要的是，主动和被动任务的阈值没有显着差异。在进一步的研究中，刺激器在神经磁记录中引入的噪声被量化，并记录主动和被动触摸的体感诱发场。由于刺激器与神经成像技术（如MEG）的兼容性，并基于记录体感相关神经磁脑活动的可行性，该装置具有探索主动触觉感知神经基础的巨大潜力。
Natural exploration of textures involves active sensing, i.e., voluntary movements of tactile sensors (e.g., human fingertips or rodent whiskers) across a target surface. Somatosensory input during moving tactile sensors varies according to both the movement and the surface texture. Combining motor and sensory information, the brain is capable of extracting textural features of the explored surface. Despite the ecological relevance of active sensing, psychophysical studies on active touch are largely missing. One reason for the lack of informative studies investigating active touch is the considerable challenge of assembling an appropriate experimental setup. A possible solution might be in the realm of virtual tactile reality that provides tactile finger stimulation depending on the position of the hand and the simulated texture of a target surface. In addition to rigorous behavioral studies, the investigation of the neuronal mechanisms of active tactile sensing in humans is highly warranted, requiring neurophysiological experiments using electroencephalography (EEG), magnetoencephalography (MEG) and/or functional magnetic resonance imaging (fMRI). However, current neuroimaging techniques impose specific requirements on the tactile stimulus delivery equipment in terms of compatibility with the neurophysiological methods being used. Here, we present a user-friendly, MEG compatible, tactile virtual reality simulator. The simulator consists of a piezo-electric tactile stimulator capable of independently protruding 16 plastic pistons of 1 mm diameter arranged in a 4 x 4 matrix. The stimulator delivers a spatial pattern of tactile stimuli to the tip of a finger depending on the position of the finger moving across a 2-dimensional plane. In order to demonstrate the functionality of the tactile virtual reality, we determined participants' detection thresholds in active and passive touch conditions. Thresholds in both conditions were higher than reported in the literature. It could well be that the processing of the piston-related stimulation was masked by the sensory input generated by placing the finger on the scanning probe. More so, the thresholds for both the active and passive tasks did not differ significantly. In further studies, the noise introduced by the stimulator in neuromagnetic recordings was quantified and somatosensory evoked fields for active and passive touch were recorded. Due to the compatibility of the stimulator with neuroimaging techniques such as MEG, and based on the feasibility to record somatosensory-related neuromagnetic brain activity the apparatus has immense potential for the exploration of the neural underpinnings of active tactile perception.