Abstract
It has been reported that the presence of others facilitates or inhibits an individual's performance. To investigate the neural bases of the effect of the presence of others, using near-infrared spectroscopy (NIRS), we measured bilateral prefrontal activation (BA 10) in humans while they performed a simulated driving task. Participants were divided into four groups according to the combination of the presence of others (Single vs. Paired) and the game experience (High vs. Low): S-H, S-L, P-H, and P-L groups. The participant's task was to drive from start to goal using a route map either driving alone without a paired partner (single condition) or driving with a paired partner as an observer (paired condition). The results revealed that the single groups (S-H, S-L) yielded more errors than the paired groups (P-H, P-L) regardless of the game experience. However, the NIRS data demonstrated an interaction between the presence of others (S, P) and the game experience (H, L): The P-H showed higher brain activity than the S-H, whereas the P-L showed lower brain activity than the S-L. These results suggest that the presence of others functions distinctively in the prefrontal cortex in participants according to their prior experience in the relevant task.