When two identical objects move toward each other, overlap completely, and continue toward opposite ends of a space, observers might perceive them as streaming through or bouncing off each other. This phenomenon is known as 'stream/bounce perception'. In this study, we investigated the effect of the presentation of emoticons on stream/bounce perception in five experiments. In Experiment 1, we used emoticons representing anger ('('∧')'), a smile ('(^_^)'), and a sober face ('(°_°)', as a control), and observers were asked to judge whether two objects unrelated to the emoticon had streamed through or bounced off each other. The anger emoticon biased perception toward bouncing when compared with the smile or sober face emoticon. In Experiments 2 and 3, we controlled for the valence and arousal of emoticons, and found that arousal influenced stream/bounce perception but valence did not. Experiments 4 and 5 ruled out the possibility of attentional capture and response bias for the emoticon with higher arousal. Taken together, the findings indicate that emoticons with higher arousal evoke a mental image of a 'collision' in observers, thereby eliciting the bounce perception.
