Results of the eleven psychological/physiological variables for the eight observations. (A) Scree plot. (B and C) Score plots of the eight observations in the PC1 vs. PC2 plane (B) and the PC1 vs. PC3 plane (C). Open symbols represent pre-treatments and closed symbols represent post-treatments: control (circle), combination of BB and IT (triangle), BB (square), and IT (diamond). The arrows between data points indicate the effects of each treatment. (D and E) PCA loadings plot of the eleven variables. (F) Distances between pre- and post-treatment in each group in the PC1. PC: principal component; BB: binaural beats; IT: isochronic tones; PCA: principal component analysis