title: Effects of spike sorting error on the Granger causality index.
abstract: Accurately sorting individual neurons is a technical challenge and plays an important role in identifying information flow among neurons. Spike sorting errors are almost unavoidable and can roughly be divided into two types: false positives (FPs) and false negatives (FNs). This study investigates how FPs and FNs affect results of the Granger causality (GC) analysis, a powerful method for detecting causal interactions between time series signals. We derived an explicit formula based on a first order vector autoregressive model to analytically study the effects of FPs and FNs. The proposed formula was able to reveal the intrinsic properties of the GC, and was verified by simulation studies. The effects of FPs and FNs were further evaluated using real experimental data from the ventroposterior medial nucleus of the thalamus. Some practical suggestions for spike sorting are also provided in this paper.
authors.affiliation: Department of Mathematics, National Central University, Jhongli 32001, Taiwan.
authors.forename: Pei-Chiang
authors.initials: PC
authors.lastname: Shao
authors.forename: Wan-Ting
authors.initials: WT
authors.lastname: Tseng
authors.forename: Chung-Chih
authors.initials: CC
authors.lastname: Kuo
authors.forename: Wei-Chang
authors.initials: WC
authors.lastname: Shann
authors.forename: Meng-Li
authors.initials: ML
authors.lastname: Tsai
authors.forename: Chien-Chang
authors.initials: CC
authors.lastname: Yen
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D001921:Brain / Q000502:physiology; D003198:Computer Simulation; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*
keywords: Granger causality index; Spike sorting; Vector autoregressive model