P3 amplitude was measured using a Visual Oddball Task in which participants were instructed to respond as quickly as possible to rare target stimuli (letter X) by pressing a button and to ignore frequent nontarget (squares) and novel (a different colored geometric figure) stimuli. The task has been previously described in detail (Pandey et al., 2020). Briefly, a total of 35 (12.5%) target stimuli, 210 (75%) nontarget stimuli, and 35 (12.5%) novel stimuli trials were randomly presented. Speed and accuracy of response were equally emphasized. Trials with baseline-corrected amplitudes greater than 75 μV were marked as artifact contaminated and not analyzed further. A minimum of 20 artifact-free correct trials to targets were selected for analysis. The peak P3 amplitude between 300 and 700 milliseconds at the midline parietal (Pz) electrode was used for analysis.
