Haptic Responses to Angry and Happy Faces

Abstract

The present aim was to investigate if angry, neutral, and happy facial expressions have different effects on haptic responses. Two experiments were conducted. In Experiment 1, participants (N = 24) were to respond as fast as they could to images of angry, neutral, and happy faces using a haptic device that measured the amount of applied force in newton units and the duration of touch in milliseconds. Experiment 2 was identical to Experiment 1, except that ratings of emotion-related experiences evoked by the stimuli were also collected in terms of valence and arousal. The results from both studies showed that the force of touch in response to angry expressions was significantly stronger than in response to happy expressions. The ratings of valence showed that angry, neutral, and happy faces were experienced statistically significantly different from each other along the dimension of valence. Ratings of arousal showed that angry faces were experienced as significantly more arousing than neutral and happy faces. The results suggest a relationship between the processing of emotion-related facial expressions and haptic response systems. The force of touch could be used as one of the measures conveying information about the user’s state of mind when interacting with haptic user interfaces.