Fig. 3.

Mean classification accuracy of emotional category as a function of principal component loadings or amygdala reactivity. Bars represent standard error of the mean. Means and standard errors are based on 1000 re-samplings. The blue line represents accuracy when the classifier was trained on the loadings of the two first principal components and tested on independent subsamples of participants. The green line marks accuracy when the classifier was trained directly on amygdala reactivity to each emotional category and then tested in independent subsamples. The magenta line represents classification accuracy when categories were scrambled randomly. Accuracy is plotted for sample sizes ranging from 10 to 150 participants increasing in steps of 10. PC, principal component.