视觉遮挡下猕猴皮质内峰电位信号的感觉解码

Sensory neural decoding of intracortical spike signals in macaques under visual occlusion

目的研究猕猴执行抓握运动时视觉信息对不同脑功能区的神经元发放机制和神经信号解码准确率的影响。方法设计一种实验装置,可有效训练猕猴在无视觉遮挡和视觉遮挡两种条件下分辨3种不同形状物体。在猕猴大脑初级运动皮质(M1)、初级感觉皮质(S1)和后顶叶皮质(PPC)植入浮动微电极阵列(FMA),通过神经数据采集系统记录猕猴执行不同形状物体抓握任务中皮质内神经信号。对猕猴的行为学数据、峰电位数据进行统计分析,采用线性判别分析(LDA)、支持向量机(SVM)和胶囊网络(CAPSNET)3种算法对神经信号进行解码。结果视觉遮挡可增加猕猴抓握过程中形状辨别的时间,3种目标抓握辨别的时间分别延长19.48%、39.71%及14.29%;CAPSNET解码器最高可实现98.21%的多脑区解码准确率,以及97.52%的单脑区解码准确率;视觉遮挡对不同脑功能区的解码准确率可产生显著影响。结论视觉遮挡可引起不同脑功能区解码准确率的改变,视觉遮挡后触觉相关脑区的功能性会增强,而视觉相关脑区的功能性则会减弱。

Objective To study the effect of visual information on the neuron firing mechanism in different functional areas of the brain and the accuracy of neural decoding when macaques perform grasping movement.Methods An experimental device for macaques was designed which could effectively train macaques to identify three objects of different shapes under no or visual occlusion.Floating microelectrode array(FMA)were implanted in the primary motor cortex(M1),primary sensory cortex(S1),and posterior parietal cortex(PPC).The data acquisition system for neural recording was used to record the intracortical neural data when the macaques performed shape recognition tasks.The behavioral data and spike data of these monkeys were statistically analyzed,while linear discriminant analysis(LDA),support vector machine(SVM)and capsule neural network(CAPSNET)were adopted for neural decoding.Results Visual occlusion increased the time taken by shape discrimination in the process of grasping something,and the time taken to discriminate the three objects was prolonged by 19.48%,39.71%,and 14.29%,respectively.The CAPSNET decoder could achieve a maximum decoding accuracy of 98.21%in multiple brain regions,and a decoding accuracy of 97.52%in single brain areas.Visual occlusion impacted the decoding accuracy of different functional areas of the brain.Conclusion Visual occlusion can make a difference to the decoding accuracy of different functional areas of the brain.After visual occlusion,the functionality of touch-related brain areas will increase,while that of vision-related brain areas will be weakened.