Table 1.
Performance of the Whole-Brain SVM Classifier.
Figure 1.
Performance of the Whole-Brain SVM Classifier is Increased by a Distance Threshold.
The classifier's performance was assessed at increasing distance thresholds. As the distance threshold increased, an increasing number of stimuli were excluded on the grounds that stimuli nearest the separating hyperplane were most likely misclassified. In this figure, performance is plotted as a function of the percentage of stimuli that have been excluded from classification. Dotted lines display the performance computed at each distance threshold. Solid lines display a third degree polynomial fit to those data.
Figure 2.
Brain Regions that Most Influenced the Whole-Brain SVM Classifier.
A permutation test was run to determine which brain regions significantly affected the whole-brain SVM classification. This figure illustrates brain regions that fall within the 90th percentile of the null distribution that was determined by permutation. Regions in the 99th percentile (p<0.01) are noted in the results section. Shades of red indicate regions where greater BOLD signal influenced the SVM to classify a stimulus as painful. Shades of blue indicate regions where greater BOLD signal influenced the SVM to classify a stimulus as non-painful.
Table 2.
Performance of the ROI SVM Classifiers.
Table 3.
Retest Validation of Performance of the Whole-Brain SVM Classifier.