Albanese Giulia Aurora, Marini Francesca, Morasso Pietro, Campus Claudio, Zenzeri Jacopo
Department of Robotics, Brain and Cognitive Sciences, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy.
Department of Informatics, Bioengineering, Robotics and Systems Engineering (DIBRIS), University of Genoa, Genoa, Italy.
Front Hum Neurosci. 2023 Mar 15;17:1000832. doi: 10.3389/fnhum.2023.1000832. eCollection 2023.
Position sense, which belongs to the sensory stream called proprioception, is pivotal for proper movement execution. Its comprehensive understanding is needed to fill existing knowledge gaps in human physiology, motor control, neurorehabilitation, and prosthetics. Although numerous studies have focused on different aspects of proprioception in humans, what has not been fully investigated so far are the neural correlates of proprioceptive acuity at the joints.
Here, we implemented a robot-based position sense test to elucidate the correlation between patterns of neural activity and the degree of accuracy and precision exhibited by the subjects. Eighteen healthy participants performed the test, and their electroencephalographic (EEG) activity was analyzed in its μ band (8-12 Hz), as the frequency band related to voluntary movement and somatosensory stimulation.
We observed a significant positive correlation between the matching error, representing proprioceptive acuity, and the strength of the activation in contralateral hand motor and sensorimotor areas (left central and central-parietal areas). In absence of visual feedback, these same regions of interest (ROIs) presented a higher activation level compared to the association and visual areas. Remarkably, central and central-parietal activation was still observed when visual feedback was added, although a consistent activation in association and visual areas came up.
Summing up, this study supports the existence of a specific link between the magnitude of activation of motor and sensorimotor areas related to upper limb proprioceptive processing and the proprioceptive acuity at the joints.
位置觉属于本体感觉这一感觉信息流，对于正确执行运动至关重要。全面理解位置觉对于填补人类生理学、运动控制、神经康复和假肢领域现有的知识空白是必要的。尽管众多研究聚焦于人类本体感觉的不同方面，但迄今为止尚未充分研究关节处本体感觉敏锐度的神经关联。
在此，我们实施了一项基于机器人的位置觉测试，以阐明神经活动模式与受试者表现出的准确性和精确程度之间的相关性。18名健康参与者进行了该测试，并分析了他们在μ频段（8 - 12赫兹）的脑电图（EEG）活动，因为该频段与自主运动和体感刺激相关。
我们观察到，代表本体感觉敏锐度的匹配误差与对侧手部运动和感觉运动区域（左中央区和中央顶叶区）的激活强度之间存在显著正相关。在没有视觉反馈的情况下，与联合区和视觉区相比，这些相同的感兴趣区域（ROIs）呈现出更高的激活水平。值得注意的是，当添加视觉反馈时，仍观察到中央区和中央顶叶区的激活，尽管联合区和视觉区也出现了一致的激活。
总之，本研究支持与上肢本体感觉处理相关的运动和感觉运动区域的激活程度与关节处本体感觉敏锐度之间存在特定联系。
