Perceptual and not physical eye contact elicits pupillary dilation.

Eye contact is important to share communication during social interactions. However, how accurately humans can perceive the gaze direction of others toward themselves and whether pupils dilate when humans consciously or unconsciously perceive own eyes are looked by others remain unclear. In this study, we examined the relationship between the explicit perception of looking into each other's eyes and the implicit physiological response of pupillary dilation by using an original face-to-face method. We found that humans do not correctly detect the gaze direction of others. Furthermore, one's pupils dilated when one gazed at others' eyes. Awareness of others' gaze on one's eyes, rather than the actual focusing of other's gaze on one's eyes, enhanced pupillary dilation. Therefore, physiological responses are caused not when people actually look into each other's gaze, but when the consciousness of other's gaze is activated, which suggests that eye contact often involves one-way communication. Crown