Curiosity during learning increases information-seeking behaviors and subsequent memory retrieval success, yet the mechanisms that drive curiosity and its accompanying information-seeking behaviors remain elusive. Hints throughout the literature suggest that curiosity may result from a metacognitive signal-possibly of closeness to a not yet accessible piece of information-that in turn leads the experiencer to seek out additional information that will resolve a perceptibly small knowledge gap. We examined whether metacognition sensations thought to signal the likely presence of an as yet unretrieved relevant memory (such as familiarity or déjà vu) might be involved. Across two experiments, when cued recall failed, participants gave higher curiosity ratings during reported déjà vu (Experiment 1) or déjà entendu (Experiment 2), and these states were associated with increased expenditure of limited experimental resources to discover the answer. Participants also spent more time attempting to retrieve information and generated more incorrect information when experiencing these déjà vu-like states than when not. We propose that metacognition signaling of the possible presence of an as yet unretrieved but relevant memory may drive curiosity and prompt information-seeking that includes further search efforts.

Previous research has shown that even when famous people's identities cannot be discerned from faces that have been filtered with monochromatic noise, these unidentifiable famous faces still tend to receive higher familiarity ratings than similarly filtered non-famous faces. Experiment 1 investigated whether a similar face recognition without identification effect would occur among faces whose identification was hindered through the wearing of a surgical mask. Among a mixture of famous and non-famous faces wearing surgical masks and hoods, participants rated how familiar each person seemed then attempted to identify the person. Though surgical masks significantly impaired identification of the famous faces, unidentified masked famous faces received higher familiarity ratings on average than the non-famous masked faces, suggesting that a sense of familiarity could still occur even when identification was impaired by the mask. Experiment 2 compared faces covered by surgical masks with faces covered by sunglasses. Though sunglasses impaired face identification more than surgical masks, the magnitude of the face recognition without identification effect was the same in both cases. This pattern suggests that holistic face processing is not a requirement for the sense of familiarity with a face, and that different facial feature types can contribute.