A Framework for the Comparative Assessment of Neuronal Spike Sorting Algorithms towards More Accurate Off-Line and On-Line Microelectrode Arrays Data Analysis

Figure 9

Performances of the methods on real data. (a) Outcome of the visual inspection on the results of the methods, where the percentage of nonclassified spikes and the ratio between the number of correctly identified clusters and the real number of clusters are reported. Each symbol represents a combination of algorithms, as indicated by the legend and annotations in the graph. -means is not represented since it does not provide unclassified spikes. (b) Box-plots (median and IQR with whiskers delimited by the maximum and minimum nonoutliers values) of the intracluster variance (ICV) for each of the FE and clustering combinations and O-sort applied to all the real signals (). The statistically significant differences are indicated as the numbers above each box-plot, the box-plot being marked with “1” referring to the methods with lowest ICV compared to all the others and the box-plot marked with “4” referred to the methods with highest ICV compared to all the others (Friedman’s test followed by Wilcoxon’s matched pair test, ).

(a)

(b)