From: Yasser on
A Graph-Laplacian-Based Feature Extraction Algorithm for Neural Spike
Sorting

PDF: http://lyle.smu.edu/~yghanbari/EMBC09_YG.pdf

Abstract—Analysis of extracellular neural spike recordings is highly
dependent upon the accuracy of neural waveform classification,
commonly referred to as spike sorting. Feature extraction is an
important stage of this process because it can limit the quality of
clustering which is performed in the feature space. This paper
proposes a new feature extraction method (which we call Graph
Laplacian Features, GLF) based on minimizing the graph Laplacian and
maximizing the weighted variance. The algorithm is compared with
Principal Components Analysis (PCA, the most commonly-used feature
extraction method) using simulated neural data. The results show that
the proposed algorithm produces more compact and well-separated
clusters compared to PCA. As an added benefit, tentative cluster
centers are output which can be used to initialize a subsequent
clustering stage.