Some researchers claim that uncertainty prolongs the duration of emotional experiences because uncertainty toward an emotion-eliciting event prolongs attention to that event. However, some results contradict this claim. We assumed that curiosity rather than uncertainty prolongs the duration of emotional experience via attention, and that attention and emotional experience are prolonged only when uncertainty elicits curiosity. This assumption is based on the information gap theory, which proposes that curiosity increases with uncertainty, but that curiosity decreases at a certain level of (...) uncertainty. We conducted a survey study to investigate the relationships among curiosity, uncertainty, attention and duration of positive and negative emotional experiences. The results showed that curiosity, but not uncertainty, prolonged the duration of emotional experiences and the process was completely mediated by attention both for positive and negative emotions. Moreover, uncertainty prolonged the duration of emotional experiences only when uncertainty elicited curiosity, which in turn prolonged attention to the emotion-eliciting event. (shrink)