Department of Neurobiology, Duke University Medical School, Durham, NC, 27710, USA.
Biomedical Engineering Department, Çorlu Engineering Faculty, Tekirdağ Namık Kemal University, Tekirdağ, 59860, Turkey.
J Comput Neurosci. 2023 May;51(2):207-222. doi: 10.1007/s10827-023-00844-0. Epub 2023 Jan 25.
Decoding of sensorimotor information is essential for brain-computer interfaces (BCIs) as well as in normal functioning organisms. In this study, Bayesian models were developed for the prediction of binary decisions of 10 awake freely-moving male/female rats based on neural activity in a vibrotactile yes/no detection task. The vibrotactile stimuli were 40-Hz sinusoidal displacements (amplitude: 200 µm, duration: 0.5 s) applied on the glabrous skin. The task was to depress the right lever for stimulus detection and left lever for stimulus-off condition. Spike activity was recorded from 16-channel microwire arrays implanted in the hindlimb representation of primary somatosensory cortex (S1), overlapping also with the associated representation in the primary motor cortex (M1). Single-/multi-unit average spike rate (R) within the stimulus analysis window was used as the predictor of the stimulus state and the behavioral response at each trial based on a Bayesian network model. Due to high neural and psychophysical response variability for each rat and also across subjects, mean R was not correlated with hit and false alarm rates. Despite the fluctuations in the neural data, the Bayesian model for each rat generated moderately good accuracy (0.60-0.90) and good class prediction scores (recall, precision, F1) and was also tested with subsets of data (e.g. regular vs. fast spike groups). It was generally observed that the models were better for rats with lower psychophysical performance (lower sensitivity index A'). This suggests that Bayesian inference and similar machine learning techniques may be especially helpful during the training phase of BCIs or for rehabilitation with neuroprostheses.
感觉运动信息的解码对于脑机接口(BCIs)以及正常功能的生物体都是至关重要的。在这项研究中,基于振动触觉检测任务中的神经活动,我们为 10 只清醒自由移动的雄性/雌性大鼠的二元决策预测开发了贝叶斯模型。振动触觉刺激为 40-Hz 正弦位移(幅度:200 µm,持续时间:0.5 s),施加在无毛皮肤。任务是按下右侧杠杆来检测刺激,按下左侧杠杆来检测刺激关闭。记录了从植入初级躯体感觉皮层(S1)后肢代表区的 16 通道微丝阵列的尖峰活动,该区域也与初级运动皮层(M1)的相关区域重叠。在刺激分析窗口内的单个/多单位平均尖峰率(R)被用作基于贝叶斯网络模型的每个试验的刺激状态和行为反应的预测因子。由于每个大鼠和跨受试者的神经和心理物理反应变异性很高,因此平均 R 与击中率和虚报率无关。尽管神经数据存在波动,但每个大鼠的贝叶斯模型产生了中等的准确性(0.60-0.90)和良好的类别预测分数(召回率、精度、F1),并且还使用数据子集进行了测试(例如,常规尖峰组与快速尖峰组)。一般来说,观察到模型对于心理物理性能较低的大鼠(较低的敏感性指数 A')更好。这表明贝叶斯推断和类似的机器学习技术可能在 BCI 的训练阶段或神经假体康复期间特别有帮助。