FIGURE 1.

Sequences of stimulus and response events in the Simon task, Type 2 task, and 2-back task. The correct hand with which to react to each stimulus is depicted in the upper right section of each stimulus. (A) Schematic illustration of the design of the study. (B) Schematic illustration of the Simon task. Participants were asked to respond with their left or right index fingers based on which character (H or S) was presented. Participants had to press with their left finger for the character “S” and with their right finger for the character “H.” (C) Schematic illustration of the Type 2 task. In the Type 2 task, participants were asked to respond with their left or right index fingers according to the type of spatial information (left or right). Participants had to press with their left finger for right-sided presentation of characters, and with their right finger for left-side presentation of characters. (D) In the 2-back task, participants had to answer whether the current stimulus was identical to the stimulus that preceded it by two. When the same stimulus as that occurring “2-back” was presented, participants were asked to respond with their right index finger. If it was different, they were to respond with their left finger. Four types of characters were used (A, H, M, S).