Figure 1

(A) Schematic illustrations of behavioral (left) and brain imaging (right) experiments. After the presentation of a fixation point and a gray ring, a visual target whose orientation tilted either left or right was presented at the center of the ring. The ring color was also changed from gray to black as the cue for the target onset. The tactile vibrations were presented to the participant’s left index finger 50 ms after the visual target presentation. Participants were asked to judge the target’s orientation in the behavioral experiment. (B) Schematic illustrations of experimental conditions. We set the four conditions depending on the presence of the tactile stimulus and spatial position of the visual target. (C) Results of the behavioral experiment. While significant effects were not observed for all participants (left panel), we focused on the relationship between the individuals’ magnitude of TIVS (right panel) and brain activities. In the left panel, error bars denote standard error of the mean. In the right panel, the magnitude of TIVS (positive values indicate stronger effects) was plotted against the proportion of correct responses for the V-left without-touch (baseline) condition. Hand images were produced by and used with permission from Shoko Yabuki.