Figure 1.

Apparatus and Task schedules. (A) Task schedules and apparatus: we adopted two conditions in which the temporal parameters of the visuotactile stimulation were varied. In the Synchronous condition, synchronous brush strokes were applied to the rubber hand and the actual hand at a constant 2-s interval. In the Asynchronous condition, the interval was randomly assigned and ranged between 1 and 3 s. Each condition included 4 blocks. The Synchronous and Asynchronous conditions were conducted on separate days. Before and after the behavioral tasks, 2 mL of saliva were collected from each participant in a centrifuge tube. In each condition, brush strokes were applied to the rubber hand and the participant's hand using a PC-controlled brush. A touch screen was placed above the rubber hand and the participant's hand. Details regarding the apparatus were described in a previous report (Ide and Wada, 2016). (B) Subjective feeling of the RHI (Items 1–3) and proprioceptive drift were calculated in each block. Filled squares indicate scores in the Synchronous condition; open circles indicate scores in the Asynchronous condition. Each point indicates the average of each block from 15 participants.