Department of Electrical and Computer Engineering, Duke University, Durham, NC, United States of America. Author to whom any correspondence should be addressed.
J Neural Eng. 2020 Feb 19;17(1):016067. doi: 10.1088/1741-2552/ab6df3.
We consider the cross-subject decoding problem from local field potential (LFP) signals, where training data collected from the prefrontal cortex (PFC) of a source subject is used to decode intended motor actions in a destination subject.
We propose a novel supervised transfer learning technique, referred to as data centering, which is used to adapt the feature space of the source to the feature space of the destination. The key ingredients of data centering are the transfer functions used to model the deterministic component of the relationship between the source and destination feature spaces. We propose an efficient data-driven estimation approach for linear transfer functions that uses the first and second order moments of the class-conditional distributions.
We apply our data centering technique with linear transfer functions for cross-subject decoding of eye movement intentions in an experiment where two macaque monkeys perform memory-guided visual saccades to one of eight target locations. The results show peak cross-subject decoding performance of [Formula: see text], which marks a substantial improvement over random choice decoder. In addition to this, data centering also outperforms standard sampling-based methods in setups with imbalanced training data.
The analyses presented herein demonstrate that the proposed data centering is a viable novel technique for reliable LFP-based cross-subject brain-computer interfacing and neural prostheses.
我们考虑从局部场电位 (LFP) 信号进行跨主体解码问题,其中从源主体的前额叶皮层 (PFC) 收集的训练数据用于解码目标主体中的预期运动动作。
我们提出了一种新的监督迁移学习技术,称为数据中心化,用于适应源特征空间到目标特征空间的特征空间。数据中心化的关键要素是用于建模源和目标特征空间之间关系的确定性分量的转移函数。我们提出了一种用于线性转移函数的高效数据驱动估计方法,该方法使用类条件分布的一阶和二阶矩。
我们在一项实验中应用了具有线性转移函数的数据中心化技术,该实验中两只猕猴执行记忆引导的视觉扫视,以指向八个目标位置之一。结果显示跨主体解码性能的峰值为[公式:见文本],与随机选择解码器相比有了显著提高。除此之外,数据中心化在训练数据不平衡的设置中也优于标准基于抽样的方法。
本文的分析表明,所提出的数据中心化是一种可靠的基于 LFP 的跨主体脑机接口和神经假体的可行新技术。