Figure 1.

Experimental setup and design. A, Baseline perceptual sensitivity to discriminate between MPs and IPs was assessed on day 1, followed by a training over 3 days where participants were trained intensively on half of the stimuli (n = 100). During the first 20 min of each training session, either tDCS over IFG, IPC, or sham stimulation was applied. After training (day 4), perceptual sensitivity of all stimuli (trained and untrained) were tested again. B, Single trial design of the same-different forced-choice paradigm during both pretest and post-test (top row) and training (bottom row). C, For tDCS, neuronavigation was used to target brain areas (left IFG and IPC) based on the subjects' individual structural MRI scans.