Participants in the visual-based oddball task (OBT, task 1) comprised 22 right-handed, healthy children (15 boys, 7 girls; , , and range: 6 to 13 years). Those for the verbal category fluency task (CFT, task 2) comprised 22 right-handed, healthy volunteers (6 participants were excluded; 16 males, 6 females; , , and range: 22 to 57 years). Those for the naming task (NMT, task 3) comprised 26 right-handed, healthy volunteers (4 participants were excluded; 19 males, 7 females; , , and range: 22 to 57 years). Written informed consent was given by all participants and, in the case of the OBT experiment, their parents. The study was approved by the Jichi Medical University ethics committee.