Proprioceptive and cutaneous sensations in humans elicited by intracortical microstimulation.
Proprioceptive and cutaneous sensations in humans elicited by intracortical microstimulation.
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DOI：
10.7554/elife.32904
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发表时间：
2018-04-10
期刊：
影响因子：
7.7
通讯作者：
Andersen RA
中科院分区：
文献类型：
--
作者：
Armenta Salas M;Bashford L;Kellis S;Jafari M;Jo H;Kramer D;Shanfield K;Pejsa K;Lee B;Liu CY;Andersen RA
非人类灵长类动物的开创性工作和最近的人类研究建立了初级体感皮层（S1）的皮质内微刺激（ICMS）作为诱导可辨别人工感觉的方法。然而，这些人工感觉还不能提供通过自然刺激可获得的皮肤和本体感觉的广度。在一个四肢瘫痪的人与两个微电极阵列植入S1，我们报告可复制的启发的感觉，在皮肤和本体感觉的方式定位到对侧手臂，依赖于幅度和频率的刺激。此外，我们发现了一个子集的电极，表现出多模态特性，这些电极上的本体感觉与更高的振幅，无论频率。这些新的结果表明，通过ICMS提供自然感知的能力，可以更接近地模仿身体的自然生理能力。此外，通过人工体感反馈传递皮肤和本体感觉可以改善脑机接口的性能和体现。遍布全身的神经通过脊髓向大脑发送关于触摸、温度、身体位置和疼痛的信息。大脑中一个叫做躯体感觉皮层的部分处理这些信息。脊髓损伤破坏了这些信息。即使躯体感觉皮层没有受损，受影响的身体区域也会失去感觉。没有治疗方法可以修复脊髓，所以感觉的丧失是永久性的。将电流施加到躯体感觉皮层可以产生人工感觉。科学家们正在测试这种方法，以恢复脊髓损伤患者的触觉。早期的实验表明，使用不同模式的电刺激会在不同的身体部位产生不自然的感觉。接受刺激的人将其描述为刺痛或电击。科学家们想知道他们是否可以改进这项技术，模仿触摸或身体位置等感觉，使脊柱损伤的人更容易移动或使用假肢。现在，Armenta Salas等人在脊髓损伤的人身上产生了更自然的感觉。他们没有采用通常的方法将大电流输送到皮层表面，而是将小电极插入皮层内部，用小电流刺激它。在实验中，电极被植入一名志愿者的躯体感觉皮层，该志愿者因脊髓损伤而失去了四肢和躯干的使用。Armenta Salas等人应用了不同的电刺激模式，志愿者报告了他们的感觉。患者描述了前臂或上臂有特定模式的捏或挤压感。在某些情况下，患者报告了手臂移动时电流更强的感觉。实验表明，对大脑的电刺激可以重现一些自然的感觉。这些感觉可以帮助使用机器人或假肢的患者变得更加灵巧。它还可以帮助患者将假肢视为身体的一部分，这可以提高他们的幸福感。
Pioneering work with nonhuman primates and recent human studies established intracortical microstimulation (ICMS) in primary somatosensory cortex (S1) as a method of inducing discriminable artificial sensation. However, these artificial sensations do not yet provide the breadth of cutaneous and proprioceptive percepts available through natural stimulation. In a tetraplegic human with two microelectrode arrays implanted in S1, we report replicable elicitations of sensations in both the cutaneous and proprioceptive modalities localized to the contralateral arm, dependent on both amplitude and frequency of stimulation. Furthermore, we found a subset of electrodes that exhibited multimodal properties, and that proprioceptive percepts on these electrodes were associated with higher amplitudes, irrespective of the frequency. These novel results demonstrate the ability to provide naturalistic percepts through ICMS that can more closely mimic the body’s natural physiological capabilities. Furthermore, delivering both cutaneous and proprioceptive sensations through artificial somatosensory feedback could improve performance and embodiment in brain-machine interfaces. Nerves throughout the body send information about touch, temperature, body position and pain through the spinal cord to the brain. A part of the brain called the somatosensory cortex processes this information. Spinal cord injuries disrupt these messages. Even though the somatosensory cortex has not been damaged, sensation is lost for the affected body areas. No treatment exists to repair the spinal cord so the loss of sensation is permanent. Applying electricity to the somatosensory cortex can produce artificial sensations. Scientists are testing this approach to restore a sense of touch for people with spinal cord injury. Early experiments show that using different patterns of electrical stimulation generates unnatural sensations in different body parts. People receiving the stimulation describe it as tingling or shocks. Scientists wonder if they can improve the technique to mimic feelings like touch or body position to make it easier for people with a spinal injury to move or use prostheses. Now, Armenta Salas et al. generated more natural sensations in a person with a spinal cord injury. Instead of taking the usual approach of delivering large currents to the surface of cortex, they inserted small electrodes into the inside of the cortex to stimulate it with small currents. In the experiments, electrodes were implanted in the somatosensory cortex of a volunteer who had lost the use of his limbs and torso because of a spinal injury. Armenta Salas et al. applied different patterns of electrical stimuli and the volunteer reported what they felt like. The patient described sensations like a pinch or squeeze in the forearm or upper arm with certain patterns. In some cases, the patient reported the sensation of the arm moving with stronger electrical currents. The experiments show that electrical stimulation of the brain can recreate some natural sensations. These sensations could help patients using robotic or prosthetic arms become more dexterous. It might also help patients view artificial limbs as part of their bodies, which could improve their sense of wellbeing.