Optimizing a linear algorithm for real-time robotic control using chronic cortical ensemble recordings in monkeys.
Optimizing a linear algorithm for real-time robotic control using chronic cortical ensemble recordings in monkeys.
复制标题
使用猴子的慢性皮质整体记录优化实时机器人控制的线性算法。
DOI：
10.1162/0898929041502652
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Nicolelis,MiguelAL
中科院分区：
文献类型：
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作者：
Wessberg,Johan;Nicolelis,MiguelAL
我们实验室以前的工作已经证明，一个简单的线性模型可以用来将皮层神经元活动转化为实时运动控制命令，使机器人手臂能够模仿受过训练的灵长类动物的预期手部运动。在这里，我们描述了一个全面的分析结果的单个皮层神经元的贡献，这个线性模型。这个模型的关键是观察到位于额叶和顶叶皮质区的大部分皮质神经元都被调整为手的位置。在大多数神经元中，手的位置调谐是时间依赖性的，在手部运动开始前的1秒期间连续变化。这一生理发现的相关性表明，只有当选择最佳参数的脉冲响应函数描述随时间变化的神经元位置调谐时，才能实现单个神经元对线性模型的最大贡献。最佳参数包括脉冲响应函数与1.0至1.4秒的时间长度和50至100毫秒箱。虽然在10分钟的训练后可以实现可靠的泛化和长期预测（60-90分钟），但我们注意到模型性能在长时间内会下降。这种退化的一部分是由于观察到神经元的位置调谐在整个记录会话的持续时间（60-90分钟）中显著变化。总之，这些结果表明，这里描述的实验范式可能是有用的，不仅调查方面的神经群体编码，但它也可能提供一个测试床的发展，旨在恢复运动功能的严重瘫痪患者的临床有用的皮质假体设备。
Previous work in our laboratory has demonstrated that a simple linear model can be used to translate cortical neuronal activity into real-time motor control commands that allow a robot arm to mimic the intended hand movements of trained primates. Here, we describe the results of a comprehensive analysis of the contribution of single cortical neurons to this linear model. Key to the operation of this model was the observation that a large percentage of cortical neurons located in both frontal and parietal cortical areas are tuned for hand position. In most neurons, hand position tuning was time-dependent, varying continuously during a 1-sec period before hand movement onset. The relevance of this physiological finding was demonstrated by showing that maximum contribution of individual neurons to the linear model was only achieved when optimal parameters for the impulse response functions describing time-varying neuronal position tuning were selected. Optimal parameters included impulse response functions with 1.0-to 1.4-sec time length and 50-to 100-msec bins. Although reliable generalization and long-term predictions (60–90 min) could be achieved after 10-min training sessions, we noticed that the model performance degraded over long periods. Part of this degradation was accounted by the observation that neuronal position tuning varied significantly throughout the duration (60–90 min) of a recording session. Altogether, these results indicate that the experimental paradigm described here may be useful not only to investigate aspects of neural population coding, but it may also provide a test bed for the development of clinically useful cortical prosthetic devices aimed at restoring motor functions in severely paralyzed patients.