Modulation of N1 amplitude and latency by perceptual learning and correlation with behavioral changes. (a) Grand average ERPs recorded at PO3 electrode during Session 1 (blue) and Session 2 (red). Vertical line at zero indicates the onset of TDT target array presentation, and the gray highlighted rectangle indicates the temporal window used for N1 analysis. Both N1 amplitude (mean N1 in Session 1: −2.04 μV, SD = 2.89; Session 2: −1.15 μV, SD = 2.75) and latency (Session 1: 159 ms, SD = 17.5; Session 2: 155 ms, SD = 19.4) decreased significantly following learning. (b) N1 topographical map 150 ms after stimulus onset for Session 1 (left), Session 2 (middle), and their difference (right). (c) N1 latency changes were negatively correlated with performance difference scores. Dotted lines indicate 95% confidence interval.