Neurophysiology of Human Perceptual Learning Figure 6. Effect of training on mean ABA amplitude over ROI-1 or left hemisphere sites. The left side of the figure depicts TF charts obtained for each of the five training sessions. The right side of the figure depicts, from top to bottom, the TF chart obtained for the control session, head plot showing the approximate position of electrodes identified for ROI-1 and quantification of the amplitude profile along training (1-5) and during control (6) session. doi:10.1371/journal.pone.0019221.g006 Figure 7. Relationship between ERP waves amplitude and perceptual learning. Top left panel shows the block-level correlation between P3 amplitude and sensitivity. Top right panel shows the block-level correlation between P3 amplitude and RT. Bottom left panel shows the block- level correlation between N2pc amplitude and sensitivity. Bottom right panel shows the block-level correlation between N2pc amplitude and RT. doi:10.1371/journal.pone.0019221.g007 PLoS ONE | www.plosone.org 10 April 2011 | Volume 6 | Issue 4 | e19221