One hundred thirty-four undergraduate psychology students reacted to an advertisement to join a laboratory experiment about interhemispheric interaction and ADHD symptoms. With an emphasis on ADHD symptoms in the advertisement we aimed to attract a larger than usual proportion of subjects with ADHD that would result in a sample with a wide range of ADHD symptoms from zero to full diagnosis. Based on the questionnaire information the following exclusion criteria were applied: (a) reported former diagnosis with ADHD and/or depression and/or anxiety but currently reporting few ADHD symptoms (i.e., CAARS score ≤65), (b) being under medication related to ADHD and/or mood disorders, and (c) self-reported left handedness.