Abstract
Current theories in curiosity research propose that our sense of curiosity is determined by the learning progress, or information gain, that our cognitive system expects to make. However, few studies have explicitly tried to quantify subjective information gain and link it to measures of curiosity. Here, we asked people to report their curiosity about the intrinsically engaging perceptual ‘puzzles’ known as Mooney images, and to report the strength of their aha experience upon revealing the solution image (curiosity relief). We also asked our participants (N = 279) to make a guess concerning the solution of the image, and we used the distribution of these guesses to compute the crowdsourced semantic entropy (or ambiguity) of the images, as a measure of the potential for information gain. We did this by computing the Shannon entropy of the probability distribution of different guesses across the total number of guesses. For example, an image with many different guess labels across participants will have a high semantic entropy, while an image with the same guess label across all participants would have low semantic entropy. Our results confirm that this semantic information gain measure is substantially associated with curiosity (r = 0.38, p < .001) and, even more so, with the aha experience (r = .55, p < .001). These findings support the expected information gain theory of curiosity and suggest that the aha experience, or intrinsic reward, is driven by the actual information gain. In an unannounced memory task after the main experiment, we also established that the often reported influence of curiosity on memory is fully mediated by the aha experience or curiosity relief (B = .01, p < .001). Our results have implications for the burgeoning fields of curiosity and psychoaesthetics.