脑机接口（brain-computer interface, BCI），有时也称作direct neural interface或者brain-machine interface，它是在人或动物脑（或者脑细胞的培养物）与外部设备间建立的直接连接通路。在单向脑机接口的情况下，计算机或者接受脑传来的命令，或者发送信号到脑（例如视频重建），但不能同时发送和接收信号。
脑-机接口是治疗因脊髓损伤造成的瘫痪的一种很有希望的方法，该方法可将控制信号从大脑重新路由到肌肉。2000年，科学家曾成功实现了一个能够在夜猴操纵一个游戏杆来获取食物时重现其手臂运动的脑机接口。
日前，美国华盛顿大学科学家研究表明，猴子可学习利用从脑中单个神经元人工路由出的信号来移动一个暂时瘫痪的手腕，人们以前并没有将这些神经元与该运动联系起来。这一结果对于今后脑-机接口的设计可能会有重要意义，这种接口的设计传统上依赖于专门的神经元类群的活动。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 456, 639-642 (4 December 2008) | doi:10.1038/nature07418
Direct control of paralysed muscles by cortical neurons
Chet T. Moritz1, Steve I. Perlmutter1 & Eberhard E. Fetz1
1 Department of Physiology & Biophysics and Washington National Primate Research Center, University of Washington, Seattle, Washington 98195, USA
Top of pageA potential treatment for paralysis resulting from spinal cord injury is to route control signals from the brain around the injury by artificial connections. Such signals could then control electrical stimulation of muscles, thereby restoring volitional movement to paralysed limbs1, 2, 3. In previously separate experiments, activity of motor cortex neurons related to actual or imagined movements has been used to control computer cursors and robotic arms4, 5, 6, 7, 8, 9, 10, and paralysed muscles have been activated by functional electrical stimulation11, 12, 13. Here we show that Macaca nemestrina monkeys can directly control stimulation of muscles using the activity of neurons in the motor cortex, thereby restoring goal-directed movements to a transiently paralysed arm. Moreover, neurons could control functional stimulation equally well regardless of any previous association to movement, a finding that considerably expands the source of control signals for brain-machine interfaces. Monkeys learned to use these artificial connections from cortical cells to muscles to generate bidirectional wrist torques, and controlled multiple neuron–muscle pairs simultaneously. Such direct transforms from cortical activity to muscle stimulation could be implemented by autonomous electronic circuitry, creating a relatively natural neuroprosthesis. These results are the first demonstration that direct artificial connections between cortical cells and muscles can compensate for interrupted physiological pathways and restore volitional control of movement to paralysed limbs.
