This study examined the effects of social signals on human impulse control functions using go/stop tasks. The study subjects were 12 healthy people. In this study, the go stimulus was either (1) an arrow image or (2) a gaze image (a social signal). The go stimulus image was shown pseudo-randomly to each subject, together with a stop stimulus. The electroencephalogram (EEG) of each subject were recorded during the go/stop task and the event-related potential was extracted. The personality traits of each subject were investigated using the Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI). The range of the error rate was smaller in the gaze trial than in the arrow-direction trial. The difference in the error rate between the gaze and arrow-direction trials decreased as the difference in the reaction time between them increased. A subject with a higher extroversion score in the NEO-FFI had a longer reaction time. How much the reaction time was prolonged was related to the early-stage component (80-115ms)and the recognition-related component (205-280ms) of the event-related potential. Therefore, the differences in the EEG of the arrow-direction and gaze trials might play a role in the occurrence of errors in association with scores for extroversion. Social signals were shown to affect human impulse control functions. It is possible that social signals affect human attention functions.

We examined the effects of viewing clown videos on physical functions and psychological conditions by comparing them with viewing landscapes videos. The subjects were seven healthy adult women and men. Each participant watched a clown and a landscape video at intervals of one to three weeks. The participants' mood evaluation, blood pressure, heart rate, autonomic nervous function and salivary amylase were compared before and after watching the videos, and the participants were asked for their impression of viewing the clown video. The salivary amylase was significantly lowered after viewing the clown video, and the depression-dejection and tension-anxiety of POMS 2 were also significantly reduced in five subjects who answered that “it was very fun” and “it was fun.” The anger-hostility and tension-anxiety of POMS 2 were significantly reduced after viewing the landscapes video. No changes in blood pressure, heart rate and autonomic nervous function were found after watching both videos The results suggested that the clowning expression was effective in relieving mood tension when it was positively felt as “fun” and was effective in reducing physical stress regardless of mood changes.