Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44016, USA.
Department of Neuroscience, Brown University, Providence, RI, 02912, USA.
Sci Rep. 2020 Jan 29;10(1):1429. doi: 10.1038/s41598-020-58097-1.
Hybrid kinetic and kinematic intracortical brain-computer interfaces (iBCIs) have the potential to restore functional grasping and object interaction capabilities in individuals with tetraplegia. This requires an understanding of how kinetic information is represented in neural activity, and how this representation is affected by non-motor parameters such as volitional state (VoS), namely, whether one observes, imagines, or attempts an action. To this end, this work investigates how motor cortical neural activity changes when three human participants with tetraplegia observe, imagine, and attempt to produce three discrete hand grasping forces with the dominant hand. We show that force representation follows the same VoS-related trends as previously shown for directional arm movements; namely, that attempted force production recruits more neural activity compared to observed or imagined force production. Additionally, VoS-modulated neural activity to a greater extent than grasping force. Neural representation of forces was lower than expected, possibly due to compromised somatosensory pathways in individuals with tetraplegia, which have been shown to influence motor cortical activity. Nevertheless, attempted forces (but not always observed or imagined forces) could be decoded significantly above chance, thereby potentially providing relevant information towards the development of a hybrid kinetic and kinematic iBCI.
混合运动学和运动学皮质内脑机接口（iBCIs）有可能恢复四肢瘫痪患者的功能性抓握和物体交互能力。这需要了解运动信息如何在神经活动中得到表示，以及这种表示如何受到非运动参数的影响，例如意愿状态（VoS），即观察、想象或尝试动作。为此，这项工作研究了当三名四肢瘫痪的参与者用优势手观察、想象和尝试产生三种离散的手抓力时，运动皮质神经活动如何变化。我们表明，力的表示遵循与先前针对定向手臂运动所示的相同的 VoS 相关趋势；即，与观察或想象的力产生相比，尝试的力产生会募集更多的神经活动。此外，VoS 调制的神经活动比抓握力更广泛。力的神经表示低于预期，这可能是由于四肢瘫痪患者的体感通路受损所致，这些通路已被证明会影响运动皮质活动。然而，尝试的力（但并非总是观察到或想象的力）可以在很大程度上被解码为高于随机水平，从而为开发混合运动学和运动学 iBCI 提供了相关信息。
