Feelings of curiosity are foundational to learning and memory, with curiosity potentially motivating information-seeking behaviors; in turn, self-motivated information-seeking subsequently strengthens the encoding of the to-be-learned information (e.g., Gruber et al. 2014
; Kang et al. 2009
; Wade and Kidd 2019
). Research has demonstrated that information that originally prompted intense levels of curiosity is more likely to be recollected in a subsequent memory test even after a delay of two weeks (Kang et al. 2009
). Further, Gruber et al. showed that, when experiencing intense levels of curiosity, participants were more likely to encode incidental information, such as a face interleaved between to-be-learned trivia information (see also Murphy et al. 2021
). Findings such as these have implications for learning in educational settings, including informing instructors on how best to motivate learners within classroom settings (e.g., Arnone and Small 1995
; Engel 2011
; Lindholm 2018
; Malone 1981
; Maw and Maw 1966
; Pluck and Johnson 2011
The mechanisms and origins of curiosity, though, are still not well understood. Gruber and Ranganath
) argue that curiosity is a cognitive state, and some theorists have proposed that curiosity is a momentary emotional–motivational state that emerges due to metacognitive monitoring (Litman 2009
), which is awareness of one’s own cognitive processes (e.g., Koriat 2007
; Nelson and Narens 1990
). Specifically, Litman
) proposed that curiosity arises from metacognitive monitoring, emerging due to a perceived gap between one’s current knowledge needs and the current accessible knowledge state; in turn, this perceived gap motivates the person to resolve the gap, with curiosity serving as an emotional–motivational experience that is directly influenced by one’s metacognitive processes. In this view, curiosity is thought to involve a match between the to-be-learned information and the participant’s capacity or urgent need to encode or discover it (e.g., Wade and Kidd 2019
). Importantly, curiosity does not appear to result from merely realizing that one does not know something. Research suggests that curiosity increases as one feels closer to attaining the as yet unknown piece of information. For example, curiosity has been shown to increase with (1) having pieces of relevant information available (Van Dijk and Zeelenberg 2007
), (2) having high relevant knowledge related to the topic at hand (Witherby and Carpenter 2022
), and (3) feeling as if a piece of information is on the tip of one’s tongue (Metcalfe et al. 2017
). These types of findings have led to the supposition that curiosity can result from a feeling-of-closeness to the as yet unattained information (Litman et al. 2005
; Loewenstein 1994
; Metcalfe et al. 2020
; Noordewier and van Dijk 2020
; Van Dijk and Zeelenberg 2007
). From this perspective, if one feels close to the unattained information, the likelihood of curiosity should be high.
An unexplored possible source of curiosity that fits with this perspective is déjà vu—the feeling of having experienced something before despite that simultaneously seeming impossible (see Cleary and Brown 2022
, for a review). Although déjà vu is a seemingly quirky aspect of memory, Schwartz and Cleary
) argued that a possible adaptive purpose of feelings of déjà vu is to prompt a search for relevant information in memory that could indicate why the situation seems so familiar. This idea, taken together with the theory that curiosity involves a feeling-of-closeness to an unattained piece of information, led us to investigate the possibility that déjà vu (and déjà vu-like states) involve curiosity. Toward this end, in the present study, we examined whether feelings of déjà vu (and its auditory analog—déjà entendu) are associated with curiosity and information-seeking behaviors.
Metacognition is the ability to think about one’s own cognitive processes, knowledge, and memory processes (e.g., Koriat 2007
; Nelson and Narens 1990
; Rhodes 2019
). It is thought to consist of two components: monitoring and control (Nelson and Narens 1990
involves the act of reflecting on one’s current state of knowledge or cognitive processes, while control
involves decisions made about how to proceed in light of the information gleaned from the monitoring. Gruber and Ranganath
) suggestion that curiosity is a cognitive state and Litman
) proposal that curiosity emerges due to metacognitive processes both fit with the idea that curiosity may be the result of metacognitive monitoring. Specifically, the state of curiosity may arise from inner reflection on one’s own knowledge in relation to a current problem at hand (the monitoring component of metacognition). In turn, the emergence of the state of curiosity might motivate a desire to discover the as yet unknown piece of information and expend resources to engage in information-seeking behaviors (the control aspect of metacognition). In the present study, we aim to arrive at a better understanding of the metacognitive monitoring factors that can lead to the state of curiosity and its corresponding information-seeking behaviors. In our effort to do so, we build upon a relatively recent theoretical suggestion in the literature—that curiosity may be driven by metacognitive feelings of being close to accessing a piece of information that has not yet been forthcoming (Litman 2019
; Metcalfe et al. 2020
1.2. Theories of Curiosity
Until quite recently, curiosity and metacognition studies have been largely separate from one another (see Goupil and Proust 2023
for a comprehensive review connecting the two domains). However, as with many cognitive phenomena, curiosity has been a topic of study since the dawn of cognitive psychology, with researchers examining not just the circumstances under which it occurs and the consequences of it, but also why humans exhibit curiosity and information-seeking behavior (e.g., Berlyne 1950
Curiosity has been described as a desire to know or experience new information, whereby accessing that information results in a reward, whether it be an external reward, such as discovering a new piece of information that will ensure survival, or an internal reward, such as the resolution of uncertainty or merely the pleasure found in acquiring information (FitzGibbon et al. 2020
; Kang et al. 2009
; Litman 2005
). In fact, the notion of merely finding pleasure in acquiring non-essential information is what has puzzled researchers of curiosity for some time, as it seems at odds with the more evolutionarily plausible purpose of curiosity: to explore one’s environment and discover crucial pieces of information for survival (e.g., Litman 2005
; Silvia 2012
). For this reason, a number of theories have attempted to capture the purpose, function, and phenomenology of curiosity as a cognitive construct.
1.2.1. Curiosity Drive Theory
One of the earliest classes of theories examining curiosity is known as curiosity-drive theory
, sometimes referred to as drive reduction theory
(see Litman 2005
). This class of theories proposes that curiosity can be equated with rather unpleasant experiences of uncertainty and reducing those feelings of uncertainty is rewarding. The main assumption behind this class of theories is that humans strive for coherence, such that there are little to no unknowns in their environment, as those could be potentially threatening for survival. Thus, whenever one encounters a novel, complex, and/or ambiguous stimulus, such as a new peculiar insect, this elicits a sense of uncomfortable uncertainty that must be resolved. The individual will seek out information, such as by inspecting or interacting with the stimulus, in order to learn about its properties and characteristics, leading to the resolution of uncertainty that could potentially threaten survival. Indeed, early research on curiosity provided support for this viewpoint, as can be seen in a series of experiments summarized by Berlyne
), who described curiosity as a “condition of discomfort, due to inadequacy of information, that motivates specific exploration” (p. 26).
In his experiments examining curiosity and information-seeking behaviors for visual stimuli, Berlyne
) presented participants with images of varying levels of ambiguity. The images he used were of animals, such as an elephant or bird, but were altered in a way, such that some of the animal’s features, such as the legs, were incongruent. Participants were presented with two images side-by-side, with one being the image of a congruent animal (e.g., a tiger) and the other being the altered, incongruent version of that animal (e.g., a tiger with the body of a camel). In monitoring eye movements and fixations, Berlyne found that participants tended to spend more time fixating on the ambiguous, strange animal containing incongruent body parts.
From these patterns of results, Berlyne
) proposed that, when presented with surprising, complex, or ambiguous stimuli, people will experience perceptual curiosity, which is interpreted as subjective uncertainty. As this is an aversive state, resolving any feelings of curiosity is desirable. Beyond perceptual curiosity, though, Berlyne also proposed that individuals can experience conceptual conflicts that lead to curiosity-resolving behaviors, such as when internal thought processes conflict, which he coined “epistemic curiosity.” This form of curiosity is thought to reflect a more intense desire to acquire new information, and this thus motivates exploratory behaviors that result in knowledge acquisition (Litman 2005
). Of specific interest to the current study is the finding that participants tended to be most curious about information that they felt was most familiar to them (Berlyne 1954
In his 1954 study examining epistemic curiosity, Berlyne first presented participants with a list of questions concerning invertebrate animals with the task being that they were to choose the correct answer from two potential answers. Participants were also prompted to indicate to which questions they would most prefer to know the answer. Upon completing this list of questions, participants reviewed a list of statements about invertebrate animals, which contained the correct answers to the previously presented list. Finally, participants were given the first list of questions again, but in the form of a free recall task. Berlyne’s results showed that participants were more likely to correctly produce the answer in the final free recall phase of the experiment for questions that prompted a desire to learn the answer (interpreted as curiosity) during the initial forced-choice recognition phase, suggesting that curiosity serves as an adaptive cognitive function for future memory access. Additionally, of great interest to the current study was Berlyne’s finding that, during the initial forced-choice recognition phase, participants were most curious about questions for which they indicated felt most familiar. When participants felt a sense of familiarity with the concept, this led to the greatest level of conflict, as it signaled that they were missing information for something that was stored within memory. Collectively, these results provide an early link between familiarity-detection, a form of metacognition, and feelings of curiosity.
) proposed that not all novel stimuli prompt a sense of curiosity, but rather the ones that contain familiar and
novel elements are the ones most likely to elicit curiosity. Berlyne
) proposed that instances of relative novelty
, in which a novel stimulus contains familiar patterns of elements, might prompt greater feelings of curiosity, as it signals conflict to the individual that their knowledge structures are not complete in terms of the current concept. This might encourage further information-seeking behaviors in order to resolve the conflict and learn new, important information that might fill the gap in terms of what is missing.
While curiosity-drive theories offered a compelling explanation of the function of curiosity, specifically that it motivates the individual to engage in information-seeking behaviors, there is extant research that offers a challenge to curiosity-drive theories. Specifically, a common, universally observed behavior in both non-human animals and humans is that organisms tend to seek out new or novel situations (Litman 2005
). Whenever an individual is in an environment that lacks novel or complex stimuli, they are motivated to seek out stimuli that offer new, ambiguous, or complex information (i.e., uncertainty). This frequently observed behavior is a challenge for curiosity-drive theorists, whose central tenet is that individuals seek to reduce uncertainty, and thus resolve curiosity. If individuals are only engaging in information-seeking behaviors to find certainty, then why would they also engage in information-seeking behaviors to find situations that present uncertainty?
1.2.2. Optimal-Arousal Theory
The shortcomings of curiosity-drive theories inspired an alternative account to why organisms demonstrate information-seeking behavior even when the information is not relevant for survival and there are currently no elements prompting a sense of uncertainty. These optimal-arousal theories
proposed that organisms aim to have an optimal level of arousal in which they are not over- or under-aroused, as both situations are unpleasant (Litman 2005
; Litman and Jimerson 2004
; Silvia 2012
). The optimal-arousal theories are similar to curiosity-drive theories in that they encompass the behaviors that organisms exhibit when faced with uncertainty (e.g., a highly ambiguous stimulus that results in over-stimulation), but with the added component of boredom. When individuals lack arousal and feel bored, they tend to seek out new experiences or stimuli that generate arousal and positive feelings of curiosity. As opposed to the curiosity-drive theorists, optimal-arousal theorists propose that the experience of curiosity itself is rewarding and involves feelings of interest and pleasure rather than negative feelings of uncertainty, although those can still occur. Individuals are motivated to seek out and engage in the learning of new information, as this is considered to be the optimal level of arousal.
Although the optimal-arousal theories are not without their own shortcomings (see Silvia 2012
for a detailed discussion), a major contribution of the optimal-arousal theories is its proposal that curiosity can emerge from boredom, not just due to survival-threatening uncertainty, which inspired a new way of thinking about curiosity. Specifically, it suggested that curiosity can occur due to both a drive-reduction state and an induction (or optimal arousal) state (Litman 2005
). This new perspective on curiosity, as discussed below, offers a means by which to frame curiosity as a form of metacognition, which is a primary goal of the current study.
1.2.3. Information Gap Theory
) proposed that humans can experience both sensory curiosity (due to surprising or complex visual patterns in the world) and cognitive curiosity (the prospect of modifying higher-order cognitive knowledge structures). Malone argued that one of the main purposes of curiosity is to signal opportunity to the individual. In other words, curiosity signals to the experiencer that their current knowledge structure lacks completeness or contains a gap, but that there is an opportunity to discover and learn new information that can be used to fill this gap. Along similar lines, Loewenstein
) proposed that people might experience curiosity due to metacognitive monitoring. When people detect that there is an information gap (formally called information gap theory
), they seek to fill that void (exerting metacognitive control). The size of the information or knowledge gap is inversely related to the intensity of curiosity. In short, the smaller the perceived gap (or the closer one feels to arriving at the needed information), the greater the curiosity. Information that is perceived to be very far from the current state of knowledge results in low levels of curiosity because the learner senses having only an incredibly small amount of knowledge about the topic and thus feels overwhelmed about the amount of information that must be learned in order to fill the void. It is when a person feels as if they are on the verge of discovering, learning, or accessing the needed information that high or intense feelings of curiosity occur. In turn, the strong sense of curiosity prompts the person to search further until resolution is found.
1.2.4. Conflict Detection
Gruber and Ranganath
) recently proposed a theory that could be considered a variant of Information Gap Theory. Specifically, they proposed the Prediction Appraisal Curiosity Exploration (PACE) framework, according to which the initial trigger of curiosity is a prediction error, whereby a person makes an error in their anticipation of something, and the conflict detection that occurs in response to the incongruency between the anticipated outcome and the actual outcome leads the experiencer to seek resolution through further information-seeking and exploration. According to this view, curiosity (and its corresponding information-seeking) is primarily brought on by conflict detection (also see Gruber and Fandakova 2021).
1.2.5. Interest-Deprivation Theory
Building on the aforementioned theories of curiosity, such as curiosity drive theories (e.g., Berlyne 1950
), optimal arousal theories (e.g., Litman 2005
; Litman and Jimerson 2004
; Silvia 2012
), and Loewenstein
) information gap theory, Litman and Jimerson
) developed the interest-deprivation theory of curiosity
. They propose that curiosity can emerge due to either the individual feeling as though they are deprived of information and wish to reduce or resolve that gap, or due to feeling a general interest that is not caused by a specific deficit or threat, but rather an enjoyment of learning something new. The latter form of curiosity, called curiosity as a feeling-of-interest
, involves positive feelings of interest and joy, along with the anticipation of learning something new. Litman and Jimerson proposed that curiosity as a feeling-of-interest is experienced when the person does not feel as though they are suffering from a lack of knowledge, but rather that it would be pleasurable to discover something new and avoid boredom. In a similar vein as the drive-reduction theory and optimal-arousal theory, curiosity as a feeling-of-interest is associated with the anticipated pleasure of finding out new information.
1.2.6. Curiosity as a Feeling-of-Deprivation
Of primary interest to the current study, though, is the form of curiosity that Litman and Jimerson
) coined curiosity as a feeling-of-deprivation
, during which the individual senses a lack of knowledge. They proposed that curiosity as a feeling-of-deprivation is a much more intense curiosity experience that involves the individual sensing that the needed information is substantive, meaningful, and could increase their subjective feelings of competence. This might involve learning the answer to a complex question, a valuable fact, or perhaps the solution to a difficult problem. Crucially, they hypothesize that curiosity as a feeling-of-deprivation is related to very intense feelings of curiosity that more strongly motivate information-seeking behaviors. As the individual perceives themselves as being closer to obtaining the piece of missing information, they experience more intense levels of curiosity, as the needed information is on the verge of being accessed (Noordewier and van Dijk 2020
As previously mentioned, Berlyne
) proposed that curiosity may result from a conflict between familiar and novel elements of a stimulus, prompting the individual to engage in information-seeking behaviors in order to resolve the uncertainty. By incorporating the information-gap theory, this proposal by Berlyne is plausible, as the individual may sense that, despite the current stimulus having familiar components, there are unknown aspects about it, signaling to the individual that they have a gap in knowledge, while, at the same time, the familiar components signal to the individual that the gap may be small; that is, the person may be on the verge of accessing the needed information to fill the gap. As discussed by Litman
), the self-awareness that one possesses a knowledge gap (and assessing the size of that gap) is a type of metacognitive judgement, as it requires that one reflects on their current level of knowledge and then engage in search processes, either internal or external, in order to fill that gap and learn more about the novel elements of the current stimulus that also somehow feels familiar.
1.2.7. Region of Proximal Learning Framework of Curiosity
) information gap theory specifically proposed that one’s perceived proximity to the needed knowledge is what determines the intensity of the curiosity experience. Specifically, people may feel the most curious about information that is not currently accessible but feels as if it is almost
accessible. As the perceived gap in knowledge narrows, the person feels extremely curious, as the information is close and almost retrievable, and therefore the person feels motivated to discover the needed information (see also Noordewier and van Dijk 2020
). In consideration of this, it may be that any metacognitive sensations signaling to the individual that they are close to accessing the information are a necessary component for triggering feelings of curiosity, henceforth referred to as curiosity as a feeling-of-closeness
, as information that does not feel close to being accessed will not signal to the individual that it is within the realm of possibility to discover, and they will therefore not feel curious to discover the missing information. It is this approach to curiosity that motivated the present study.
A recently proposed framework that integrates the components of prior curiosity theories, while also building on the idea that curiosity emerges when the experiencer feels on the verge of accessing relevant information, is the Region of Proximal Learning Framework of Curiosity (Metcalfe 2023
; Metcalfe et al. 2017
). The central feature of the region of proximal learning framework is that people are the most curious when they feel that they are close to knowing the desired target information. In this framework, in order to arrive at a decision (such as deciding on the answer to a question), an initial probe leads the experiencer to compile all available information, both internal and external, that is relevant to the probe. If the compiled information is sufficient enough to produce an answer, then the experiencer does so and does not have any changes in curiosity. However, if they are unable to produce an answer, or receive feedback that their provided answer was wrong, then they must make a metacognitive judgment as to their next action – give up and mind wander, which occurs when the perceived gap in knowledge is sensed to be quite large, or engage in information-seeking behaviors to resolve the gap, which occurs when the experiencer senses that the compiled information is almost
sufficient. In these moments, when the experiencer is in their region of proximal learning, they will experience heightened levels of curiosity, which motivate them to seek out and learn further information, potentially resulting in the reward of achieving the desired knowledge state. According to this framework, people will experience the strongest levels of curiosity when their metacognitive experiences suggest that they almost
know the answer. In other words, they have a sense of curiosity as a result of a metacognitive feeling-of-closeness to the sought after information.
In a compelling series of experiments examining curiosity and confidence, Metcalfe et al.
) presented participants with general knowledge questions that were each accompanied by prompts concerning whether the participant knew the answer, how curious they were, and how confident they were about their answer. When examining the relationship between confidence and curiosity, Metcalfe et al. found, unsurprisingly, that when the participant was indeed correct in their answer, curiosity and confidence followed an inverted-U relationship, such that the highest levels of confidence (e.g., 90% confident) were accompanied by lower levels of curiosity when the knowledge gap had been bridged. In short, when the participant did indeed know the answer (without receiving feedback), they were not very curious on trials associated with high confidence. However, the fascinating results are those concerning the curiosity and confidence ratings when the participant was wrong in their response. Unlike the inverted-U relationship that curiosity and confidence followed when the participant was correct, the relationship between curiosity and confidence when the participant was wrong (i.e., the knowledge gap had not yet been resolved) did not follow the same inverted-U relationship as when the participant was correct. At high levels of confidence (e.g., 90% confident), participants provided higher curiosity ratings during trials on which they were wrong in their answer as opposed to when they were correct. Critically, this relationship emerged prior to receiving feedback. The participants had not received feedback concerning whether or not their provided response was accurate, yet there was a difference in the provided curiosity ratings, as if there was some level of unconscious knowledge that their knowledge gap was not resolved, with feelings of curiosity signaling this discrepancy. In other words, it was as if they could detect that they were close to achieving the target knowledge state, but were not quite there yet.
1.2.8. What Elicits a Feeling of Closeness?
A current gap in the literature concerns how it is that people are able to metacognitively detect that they are close to arriving at a piece of information that will resolve a current gap in knowledge. The notion that there may be something akin to a feeling of closeness to a desired piece of as yet inaccessible information is reminiscent of the metacognitive phenomenon known as the tip-of-the-tongue (TOT) state.
1.3. Tip-of-the-Tongue (TOT) States
A TOT state occurs when a person feels on the verge of retrieving a word that currently eludes them; the word is said to feel “on the tip of the tongue,” as if about to come to mind at any moment (e.g., Brown 2012
; Schwartz 2002a
). Indeed, recent research has suggested that the TOT state involves a feeling of closeness to the sought after target information (Rousseau and Kashur 2021
), and a growing body of studies suggests that TOT states are linked to increased curiosity to discover the sought after information relative to when there is no TOT state for an unknown answer (Metcalfe et al. 2017
) and to corresponding information-seeking behaviors (Cleary et al. 2021b
; Metcalfe et al. 2017
; Schwartz 2002b
1.3.1. An Association between TOT States and Curiosity
A study conducted by Litman et al.
) provided initial evidence for a relationship between feelings of curiosity and TOT states. In their experiment, participants were presented with general knowledge questions and asked to make a “Know”, “TOT”, or “Don’t Know” response, along with the intensity of their confidence in being able to select the correct answer from a list of potential options and how they were curious to see the correct answer. Upon completing the general knowledge phase (and potentially a recognition memory test), all participants completed an exploratory behavior phase, during which they were given envelopes containing all of the correct answers to the general knowledge questions. Participants were told that they were free to open any of the envelopes but should focus on opening the ones for which they were genuinely interested in seeing the answers. Of most interest to the current study was the finding that participants were more curious to discover the unretrievable answer to a general knowledge question and were subsequently more willing to use limited resources to discover that answer when experiencing a TOT for that answer than when not. Additionally, when participants made a “Don’t Know” response, they showed intermediate levels of curiosity and information-seeking behaviors. “I Know” responses were accompanied by the lowest levels of curiosity and information-seeking behaviors. However, Litman et al.’s design choices did not allow for a clear connection between in-the-moment decision-making processes and TOT states, as participants were given the opportunity to discover the answers at the end of the experiment as opposed to in the moment of retrieval failure. Additionally, Litman et al. only presented 12 general knowledge questions in their experiment.
In a follow-up to this initial study, Metcalfe et al.
) used a larger number of stimuli (82 general knowledge questions) and a design that allowed for the examination of in-the-moment changes to decision-making processes as a result of TOT states. After attempting to answer each question, participants were asked to indicate whether they were in a TOT state and also whether they were curious to discover the answer. However, participants were informed that, although they could see the correct answer at a later time, they could only see the correct answer for up to 10% of the questions. Overall, although this design did not allow for immediate resolution to participants’ perceived knowledge gaps, Metcalfe et al. found that, when failing to recall the correct answer, participants were twice as likely to want to see the answer when they were in a TOT state as opposed to a non-TOT state, suggesting that participants are more curious when experiencing a TOT state and are more inclined to devote limited experimental resources toward discovering the target.
1.3.2. An Association between TOT States and Information-Seeking Behavior
The idea that TOTs might prompt information-seeking behavior has been supported in other studies as well. Schwartz
) found that participants were more likely to engage in retrieval search efforts when experiencing a TOT relative to when not. Additionally, Cleary et al.
) found that, when offered the opportunity to select the target answer from multiple-choice options despite being faced with the possibility of losing or gaining points depending on the correctness of their selection, participants were more likely to choose to see the multiple-choice options and were also more likely to select the correct answer if they were in a TOT state compared to a non-TOT state. These findings are consistent with other research examining knowledge gaps and information-seeking behaviors (e.g., FitzGibbon et al. 2020
; Gruber et al. 2014
; Kang et al. 2009
; Wade and Kidd 2019
), suggesting that participants should be more likely to spend limited resources when experiencing a perceived gap in knowledge, as they are curious to discover the missing piece of information.
Taken together, the aforementioned studies (Cleary et al. 2021b
; Litman et al. 2005
; Metcalfe et al. 2017
; Rousseau and Kashur 2021
; Schwartz 2002b
) suggest that one possible means by which people experience a feeling of closeness to a desired piece of information that could resolve a perceived small knowledge gap is the TOT state. Moreover, these studies suggest a direct link between TOT states, curiosity, and information-seeking behaviors. This points toward the possibility that metacognitive sensations of memory that occur during retrieval failure, such as the TOT state, are a cognitive means by which curiosity and its corresponding information-seeking behavior can emerge.
1.4. Déjà vu-Like States
Another way in which a sensation of closeness to a piece of information that has the potential to resolve a current knowledge gap might emerge through metacognitive monitoring is through déjà vu-like states. Déjà vu is the feeling of having experienced a current situation before, while simultaneously believing that this is the first time the situation has ever been encountered (e.g., Brown 2003
; Cleary and Brown 2022
). Whereas, the TOT state is described as a feeling of being on the verge of retrieving an as yet unretrievable word. Cleary et al.
) describe the déjà vu state as possibly involving a feeling of being on the verge of recollecting from memory how a scene or scenario is going to unfold before a person (or being on the “tip of an experience,” p. 1439).
Moreover, Schwartz and Cleary
) proposed that, as has been proposed for TOT states, an adaptive function of both TOT and déjà vu states might be to engage in further information-seeking behaviors. That is, the déjà vu state, while seeming jarring and puzzling in the moments that it is being experienced, might serve the useful function of prompting the experiencer to direct attention and cognitive effort toward a search of memory to discover the reason for the sensation. From this perspective, the déjà vu state (and déjà vu-like states) might be expected to be associated with curiosity and information-seeking behaviors similarly to how TOTs have been shown to have such an association. Establishing such a connection would add another missing puzzle piece that will help to link the curiosity literature with the metacognition literature in the growing effort to understand the mechanisms behind curiosity. Additionally, as noted by Litman
), a remaining gap in the literature is attempting to link curiosity and metacognition concerns when a person fails to retrieve visual or auditory information, as research to date has only focused on instances in which the individual fails to remember the answers to general knowledge questions.
1.5. The Present Study
The present study examined whether déjà vu and déjà vu-like states (i.e., the auditory version of déjà vu known as déjà entendu) are associated with curiosity and information-seeking behaviors. Toward this end, the present study combined a paradigm that has been used to study reports of déjà vu (Experiment 1)—and also a paradigm that has been used to study reports of déjà entendu (Experiment 2)—with the method of examining curiosity and information-seeking behavior used by Metcalfe et al.
) in their study of TOT states.
1.5.1. A Paradigm for Studying Déjà vu Reports
The paradigm used in Experiment 1 of the present study follows from past empirical work on déjà vu reports. In past work, researchers have used a test paradigm in which otherwise novel test scenes share spatial features with earlier viewed scenes. For example, Cleary et al.
) used immersive three-dimensional scenes in a virtual reality environment to examine how novel scenes that share a spatial configuration (e.g., a hedge garden scene with a particular spatial layout) with a previously viewed scene (e.g., a junkyard scene with that same spatial layout) might prompt a sense of déjà vu in cases of recall failure (see Figure 1
). Participants were more likely to report déjà vu if a test scene spatially mapped onto a studied scene that failed to be recalled than if it did not. Later, Cleary and Claxton
) and Cleary et al.
) demonstrated a similar pattern with dynamic video-based first-person virtual tours through the same scenes. This general paradigm has also shown strong associations between déjà vu reports and other metacognitive judgments, such as feelings of prediction (Cleary and Claxton 2018
; Cleary et al. 2021a
) and feelings of postdiction (Cleary et al. 2019
In Experiment 1 of the present study, we searched for an association between déjà vu reports and feelings of curiosity regarding the potential experimental source of any perceived familiarity with a test scene. We also searched for an association between déjà vu reports and information-seeking behaviors. One way that we did this was to examine participant inclinations to expend limited experimental trials toward discovering the source of any perceived familiarity with a scene, analogously to what was done in Metcalfe et al.
) investigation of TOT state. Another way that we did this was to examine possible proxies for memory retrieval search effort, such as the tendency to make commission errors while trying to retrieve relevant information, which has been shown to be associated with TOT states (Huebert et al. 2023
) and with increases in perceived stimulus familiarity (Carlaw et al. 2022
), as well as the amount of time spent at the prompt trying to retrieve a possible source for any perceived familiarity.
1.5.2. A Paradigm for Studying Déjà Entendu Reports
As previously discussed, Litman
) called for additional research examining the mechanisms and consequences of curiosity for auditory information, an under-investigated area. Therefore, in Experiment 2, we instead used an auditory paradigm as a means of investigating an auditory déjà vu-like experience, often termed déjà entendu. Déjà entendu is the feeling of having heard something before despite believing that it is new (Brown 2003
; Cleary and Brown 2022
; McNeely-White and Cleary 2019
). In the first study to empirically examine déjà entendu, McNeely-White and Cleary
) sought to use auditory analogs to the visual scenes used in the aforementioned déjà vu experiments. Toward this end, they used Piano Puzzlers, which are re-writes of original famous modern songs, such as children’s tunes, pop-songs, or folk songs, in the style of a classical composer, such as Mozart, Chopin, or Bach, by composer Bruce Adolphe for a program on NPR in which callers attempt to identify the song and genre from the Piano Puzzler. The original song is embedded within the Piano Puzzler, such that some of the original features are intact yet masked by the chosen classical composer’s genre. For example, the familiar song “The Girl from Ipanema” might be turned into a Piano Puzzler by embedding phrases of the original melody within a novel song written in the style of Brahms. Piano Puzzlers often elicit a feeling of being on the verge of identifying the song, as illustrated by people who call into the radio program to try to identify the song, and Piano Puzzlers can be seen as auditory analogs to the juxtaposition of novel and familiar scene aspects in the aforementioned studies of déjà vu.
) experiment was an auditory analog to the aforementioned scene-based déjà vu paradigm used by Cleary and colleagues (Cleary et al. 2012
; Cleary and Claxton 2018
). Participants received an auditory study list with the original versions of clips of well known songs (e.g., “London Bridge”, “Pop Goes the Weasel”) before being presented with a test list of Piano Puzzlers. Half of the Piano Puzzlers corresponded to song clips that had been presented during the study, while the other half corresponded to original song clips that were not studied. Participants were asked to indicate whether they were experiencing déjà entendu for the Piano Puzzler, how familiar they found the song to be, and whether they could identify the song. Although having recently heard the original song clip during the study phase did not significantly increase the probability of reporting déjà entendu for the Piano Puzzler at test, a further analysis revealed that, when familiarity ratings provided during test song identification failure were examined as a function of both déjà entendu reports and study status (whether or not the original song clip was presented at study), a significant effect emerged. Specifically, while experiencing test song identification failure, participants were able to use feelings of familiarity to discriminate between Piano Puzzlers whose original song clips were experimentally familiarized during the study phase versus those that were not, but only during instances in which they also reported a sense of déjà entendu. This pattern of discrimination was not shown among non-déjà entendu reports.
In Experiment 2, we aimed to potentially create a stronger manipulation of auditory familiarity in order to increase the likelihood of déjà entendu reports. Specifically, because Piano Puzzlers do not allow for experimental control over the musical feature overlap between recently heard song clips and the Piano Puzzler test clips, in the present study, we aimed to have a high degree of experimental control over the degree of auditory feature overlap between the study clips and the test clips. Because the degree of feature overlap has been shown to be a major contributing factor to how familiar a test cue seems during retrieval failure (Huebert et al. 2022
; McNeely-White et al. 2021
; Ryals and Cleary 2012
), and because this is grounded in theory regarding the purported computational mechanisms behind perceived cue familiarity (Clark and Gronlund 1996
; McNeely-White et al. 2022
), in Experiment 2, we used differing degrees of global auditory feature overlap between the test song clips and study song clips as our means of systematically attempting to increase perceived test song clip familiarity during retrieval failure (e.g., McNeely-White et al. 2021
To achieve this in the present study, during the test, participants were presented with isolated tonal features from a well known song clip (e.g., “Mary Had a Little Lamb”). These were the notes from the song clip in their correct order but attached to an arbitrary rhythm (Kostic and Cleary 2009
; McNeely-White et al. 2021
), making the song difficult to identify, but potentially familiar-seeming. Each test song clip corresponded to an unaltered piano song clip that had been played in its original rhythm either three times throughout the study phase (Exposure 3x), once throughout the study phase (Exposure 1x), or not at all during study (Exposure 0x). Our logic was that increasing perceived test song clip familiarity during retrieval failure through increased auditory global feature matching to the study phase would increase the likelihood of reporting déjà entendu, thereby enabling us to examine the potential relationship between déjà entendu and curiosity, and between déjà entendu and the information seeking behaviors examined in Experiment 1 (i.e., (1) expenditure of limited experimental opportunities for learning the answer to whether an experimental source potentially produced any sense of familiarity and, if so, what are (2) the rate of commission errors and (3) the amount of time spent at the prompt trying to retrieve a possible experimental source of any potential familiarity).
1.5.3. Resemblance of Our Methods to Berlyne’s Proposal
Note that our methods of studying déjà vu and déjà entendu are reminiscent of the aforementioned proposal put forward by Berlyne decades ago regarding curiosity (e.g., Berlyne 1950
). Berlyne proposed that some forms of curiosity might emerge when the individual is presented with a novel stimulus that contains familiar elements, creating a strange juxtaposition between old and new elements. Although this specific proposal has yet to be experimentally investigated, the paradigms used to study déjà vu and déjà entendu involve this type of juxtaposition of familiarized and novel elements, and in this way, present yet another means by which the present study adds an important puzzle piece to the overall literature to help to further tighten the link between curiosity and metacognition studies.
8. General Discussion
In the present study, we present two experiments designed to examine the relationships between metacognitive sensations of closeness to an as yet unretrieved memory (i.e., déjà vu and déjà entendu), curiosity, and subsequent information-seeking behaviors. We specifically examined whether participants experiencing déjà vu-like states would provide higher curiosity ratings and additionally demonstrate altered decision-making behaviors, such as being more inclined to use limited resources to discover the target information or spending longer amounts of time attempting to internally retrieve the target information. In each experiment, we used the RWI paradigm to manipulate whether the current test stimulus, either a novel visual environment or novel song, contained experimentally familiarized features, such as spatial layout (Experiment 1) or tonal sequences (Experiment 2) from the study phase. After each test stimulus was presented, participants were given the opportunity to use limited experimental opportunities to discover the corresponding information from the study phase, even at the risk of being told that there was no corresponding information.
In Experiment 1, we replicated prior findings from the déjà vu literature (e.g., Cleary et al. 2012
), demonstrating that participants were more likely to report a sense of déjà vu for novel test scenes that contained the same spatial layout as an unrecalled study scene compared to test scenes that did not. In Experiment 2, we demonstrated that participants were more likely to report a sense of déjà entendu for unidentified novel test songs that contained experimentally familiarized tonal information compared to those that did not, extending the prior work examining déjà entendu (e.g., McNeely-White 2020
; McNeely-White and Cleary 2019
Critically, though, the present experiments demonstrate novel findings pertaining to retrieval-failure-based metacognitive states and curiosity as a feeling-of-closeness. When participants reported experiencing déjà vu-like states, which have been considered a metacognitive state reflective of momentary retrieval failure, they concurrently reported heightened levels of curiosity compared to when they did not report experiencing déjà vu-like states. Additionally, instances of déjà vu and déjà entendu were associated with alterations in information-seeking behaviors, both internal and external. While experiencing déjà vu (Experiment 1) or déjà entendu (Experiment 2), participants across both experiments spent longer amounts of time attempting to retrieve the target information, as evidenced by the longer time spent on the Recall prompt. They also made significantly more commission errors, suggesting increased internal search efforts to conjure up potentially relevant target information. Finally, they were also more likely to expend their limited experimental opportunities to potentially receive the target information and thus resolve their metacognitive sensations of curiosity and déjà vu or déjà entendu. Overall, these findings demonstrate that metacognitive sensations of déjà vu-like states are associated with increased curiosity and information-seeking behaviors. Our experimental findings have implications for the mechanisms that may give rise to curiosity as a feeling-of-closeness and also the potential purpose that the metacognitive states of déjà vu and déjà entendu may serve in the larger memory system.
Emerging research within the metacognitive domain has begun to suggest that curiosity may emerge due to metacognitive processes, sometimes emerging as a metacognitive signal to the experiencer that their perceived knowledge gap may be close to resolution (e.g., Brooks et al. 2021
; Kang et al. 2009
; Litman and Jimerson 2004
; Metcalfe et al. 2017
). In his formal theory proposing that curiosity may arise due to metacognitive monitoring, Litman
) proposed that curiosity may emerge when the experiencer perceives a gap in their current knowledge state and the target knowledge state, which in turn motivates them to resolve the gap. From a metacognitive perspective, these two states (perceiving a gap and attempting to resolve the gap) might be viewed as monitoring and control processes. In support of this perspective, research has indeed demonstrated that metacognitive states often associated with momentary retrieval failure but simultaneously feeling close to retrieval success (e.g., TOT) are linked with heightened levels of curiosity. In their 2017 study, Metcalfe et al. demonstrated that the retrieval-failure-based metacognitive sensation of TOT is associated with heightened levels of curiosity and inclinations to spend limited resources to resolve the state. In the present experiments, we provide further support for the viewpoint that curiosity can emerge as a feeling-of-closeness, signaling to the experiencer that they should continue in their search efforts for the target information, either internally or externally, particularly during the metacognitive states of déjà vu and déjà entendu.
From a theoretical perspective, these relationships may be emerging due to the participant detecting that their knowledge gap is small, therefore making it attainable to achieve the desired knowledge state if further search efforts are undertaken (Loewenstein 1994
). According to Loewenstein’s information gap theory of curiosity, the size of the perceived knowledge gap is inversely related to the intensity of experienced curiosity, with small perceived gaps in knowledge producing intense levels of curiosity, which in turn motivate information-seeking behaviors. The results found in the present experiments are consistent with Loewenstein’s theory. During instances of déjà vu or déjà entendu, the experiencer is feeling both intense levels of subjective familiarity and novelty, which signals to them that, although there are unknowns about the current situation and they have not yet resolved the gap in knowledge, resolution is possible, as the familiarity sensations signal to the experiencer that there is relevant knowledge held within their memories which can potentially be accessed given further searching. Additionally, based on Litman and Jimerson
) interest-deprivation theory of curiosity, moments in which participants detect that they do not know something (i.e., curiosity as a feeling-of-deprivation) should be associated with intense levels of curiosity, as the experiencer is detecting that the information will meaningfully increase their knowledge structures and be rewarding to obtain.
In light of the region of proximal learning framework of curiosity, it may be that during feelings of déjà vu or déjà entendu, the participant is within their region of proximal learning and therefore feels highly curious and motivated to resolve the gap (Metcalfe 2023
; Metcalfe et al. 2017
). When presented with the test probe, either a visual scene or a song clip, the participant may sometimes detect a signal that something
about the current situation is highly familiar. This familiarity-detection in turn may be taken to indicate that relevant information likely resides within memory, making the needed information feel close to conscious access, thereby motivating the person to continue in their search efforts, either internally or externally, to resolve the state. Based on the region of proximal learning framework, participants should experience the strongest levels of curiosity when their metacognitive judgments reflect a state of almost
knowing the answer (i.e., curiosity as a feeling-of-closeness), and déjà vu-like states may afford a feeling of almost
knowing something. Along these lines, Cleary et al.
) suggested that déjà vu might be akin to feeling on the “tip of an experience,” whereby one feels as if on the verge of recalling how the entire current episode is about to unfold. All in all, the present results are consistent with these ideas, as instances in which participants reported a sense of non-déjà vu or non-déjà entendu were associated with lower levels of curiosity compared to instances in which participants did
report a sense of déjà vu or déjà entendu, perhaps suggesting that participants felt close to resolving the momentary knowledge gap that was perceived to be small during these strange metacognitive states.
An important future direction is to focus on untangling the temporal dynamics of retrieval-failure-based metacognitive sensations, curiosity as a feeling-of-closeness, and information-seeking behaviors that might in turn lead to successful retrieval. In the current experiments, we were unable to collect the dynamically unfolding mental events occurring as the participant processed a test stimulus. Based on the region of proximal learning framework of curiosity, people should be the most curious when they detect that they almost
know the answer to a question and therefore engage in search efforts to achieve that knowledge state. In our current experiments, might it be that during the timeframe of the test stimulus unfolding before the participant, they initially experienced retrieval-failure, sensed that something about the test stimulus was highly familiar, which triggered a sense of curiosity, which in turn led to internal search efforts that eventually resulted in successful retrieval? Though the current experimental design does not allow us to address this question (as participants were only prompted at the end of a given trial to indicate their metacognitive sensations, and instances of recall success that may have followed initial metacognitive sensations are undifferentiable from instances of recall success that occurred seemingly instantly upon being presented with a test stimulus), the proposition is plausible and could potentially be examined with an experimental design aimed at capturing temporal dynamics of mental experiences. An example is the Think Aloud approach (e.g., Austin and Delaney 1998
The importance of disentangling these sequences can be seen in the present data. In Experiment 1, without considering featural overlap or reported déjà vu state, participants provided the highest curiosity ratings when they successfully recalled the corresponding information from study (Mdn
= 5.11, Range
= 10.00) compared to when they failed to recall the corresponding information (Mdn
= 3.26, Range
= 9.34), W
= 1926.00, p
< .001, rrb
= 0.64, BF10
= 2.28 × 103
. These findings, at first glance, are in stark contrast with the current perspectives on curiosity and retrieval status (e.g., Loewenstein 1994
; Metcalfe et al. 2020
). According to the region of proximal learning framework of curiosity, instances of correctly knowing the answer should be accompanied by lower levels of curiosity—why would one be curious about something that they already know? Indeed, as shown by Metcalfe et al.
), instances of correctly identifying the answer to a general knowledge question were accompanied by lower levels of curiosity compared to instances of failing to identifying the answer, suggesting that participants were curious to discover the unidentified answer. However, upon closer consideration, might this discrepancy be due to the nature of the tasks? In typical experiments examining curiosity, participants are presented with static stimuli, whether it be a general knowledge question (e.g., Kang et al. 2009
; Metcalfe et al. 2017
; Wade and Kidd 2019
; Witherby and Carpenter 2022
) or a face (Brooks et al. 2021
). Once the probe appears, the participant is able to rapidly compile relevant internal information and make a metacognitive decision, which is quickly captured by the experimenters, as the relevant prompts appear soon after the probe. However, in the present study, the potential processes are complicated due to the temporally dynamic nature of the stimuli. When a test probe is presented, such as a virtual environment or a song, the participant is receiving unfolding information as time goes on, perhaps engaging in multiple compilation processes of relevant information from both the dynamically unfolding external probe playing out before them and their internal search efforts. This potential process of receiving dynamically unfolding external information that is incorporated into their compilation of evidence is not captured in the current experiments, as the participant is only prompted at the end of the trial to indicate their metacognitive judgements and retrieval attempts. Might it be that some of these trials associated with identification success were initially instances of retrieval failure
accompanied by familiarity or a déjà vu-like state, but due to the nature of the temporally dynamic probes and the timing of the experimental prompts, we are unable to capture those search processes? If curiosity does indeed breed information-seeking behaviors during instances in which the participant feels that they almost
know the answer, then it would be plausible to assume that the patterns of results previously reported (the increased curiosity ratings during instances of retrieval success as opposed to retrieval failure) are largely due to the metacognitive control processes that curiosity engenders—the participant engaged in search efforts that eventually led to retrieval success, perhaps via self-generation of candidate information, about which the participant may have been uncertain as to its correctness (thereby seeking feedback). Future research should focus on disentangling the dynamics of curiosity and search efforts during temporally unfolding stimuli, such as through the aforementioned Think Aloud approach.
The patterns of results presented in the current study also have implications for the potential adaptive purposes that retrieval-failure-based metacognitive states serve within the larger memory system. In their 2016 chapter, Schwartz and Cleary proposed that one reason people might experience metacognitive sensations during retrieval failure, such as TOT or déjà vu, is due to the memory system detecting that something is amiss. The sensations may serve as a signal to action, indicating to the experiencer that something about the current situation is relevant to stored memories, and with additional metacognitive control efforts, such as internally-directed attention for retrieval attempts or externally-directed attention to one’s environment for relevant cues and clues, the discrepancy might be resolved. Within the TOT literature, such an adaptive association has been demonstrated, with researchers presenting experiments establishing the connections among curiosity and information-seeking behaviors with TOT states (e.g., Litman 2005
; Metcalfe et al. 2017
Within the déjà vu literature, though, such evidence has not yet been put forth until the present experiments. We demonstrate that déjà vu and déjà entendu are indeed associated with heightened levels of curiosity, which result in participants engaging in additional external and internal search efforts. While experiencing déjà vu-like states, participants across both experiments tended to expend their limited experimental opportunities to resolve the metacognitive sensations and also tended to exhibit increased internally-directed search efforts, such as increased time spent attempting to retrieve the target answer and increased rates of commission errors. These results are the first to formally provide support for the proposal put forth by Schwartz and Cleary
), demonstrating that déjà vu-like states may indeed signal to the experiencer to engage in additional search efforts to further complete their memory and knowledge structures for the external world. Future research should continue to examine other ways in which déjà vu-like states are associated with adaptive cognitive functions and memory outcomes.
Future research should also examine how déjà vu-like states might impact subsequent memory as a consequence of the associated curiosity and information-seeking behaviors. For example, might an initial experience of déjà vu or déjà entendu later make an item more memorable or recognizable? That is, if one is indeed engaging in increased internally-directed search efforts while experiencing déjà vu-like states for a given stimulus, might they be further strengthening any existing memory traces (and new memory traces created due to the present encoding experience) for that stimulus, which in turn will be more easily activated upon subsequent presentation of the same stimulus? One possible outcome of experiencing déjà vu-like states and accompanying curiosity and information-seeking behaviors might be that one is better able to recognize that original stimulus that prompted the sense of déjà vu, which may suggest that not only does déjà vu serve as a metacognitive signal to make additional search efforts, but also serves as an initial signal to further enforce one’s memory structures in order to avoid such a knowledge discrepancy again. Prior research within the curiosity domain, such as Kang et al.
), has demonstrated that initial curiosity for an item is associated with later memory success.
Beyond the metacognition domain, the present results also have novel implications for the curiosity domain, specifically by providing a mechanism by which curiosity as a feeling-of-closeness might emerge. In his 1950 relative novelty
proposal, Berlyne suggested that some forms of curiosity might emerge due to the current novel probe containing a subset of familiar features, creating a strange juxtaposition of old and new, signaling to the experiencer that there is an aspect of an old object that they do not yet know. Although Berlyne’s early research demonstrated some support for such a circumstance to prompt feelings of curiosity (e.g., Berlyne 1954
), there has been little research experimentally investigating the proposal since its original development. The present experiments provide direct support for such a circumstance under which curiosity can emerge. Across both experiments, we presented participants with novel test stimuli, such as virtual environments or songs, that potentially contained experimentally familiarized features, such as spatial relations among objects or tonal sequences. Upon encountering these situations, regardless of whether they were able to identify the original source of the familiarity, participants were significantly more curious about these stimuli compared to those that did not contain experimentally familiarized sub-features. Further, in Experiment 2, the magnitude of the relationship between feelings of curiosity and the experimental manipulation of feature exposure (Exposure 0x, Exposure 1x, Exposure 3x) correspondingly increased, such that as the level of featural match between one’s prior memory traces increased, so did their perceived feelings of curiosity, perhaps suggesting that some forms of curiosity emerge due to feature-matching processes. These patterns of results are similar to those found within the literature examining features held within memory traces and the use of familiarity-detection in recognition memory decisions (e.g., Huebert et al. 2022
; McNeely-White 2020
; McNeely-White et al. 2021
; Ryals and Cleary 2012
), demonstrating that as the level of featural overlap between the current probe, whether it be a song or a non-word, and prior memory traces created during the encoding phase increases, the level of familiarity-intensity during retrieval failure correspondingly increases, signaling to the experiencer that, even though they are momentarily experiencing retrieval failure, it is likely that the target information is indeed held within memory, as evidenced by the intense feelings of familiarity. Collectively, the patterns of results found in the present study, in conjunction with those previously reported in the literature, provide support for Berlyne’s relative novelty
proposal, as they offer a potential mechanism by which perceived familiarity and novelty may prompt a momentary sense of curiosity to resolve the strange sensations.
In consideration of the present findings, such as the significant, positive correlations between feelings of familiarity and curiosity during retrieval failure, there is now reason to speculate that curiosity as a feeling-of-closeness may be supported by similar mechanisms as those that support familiarity-detection during retrieval failure, namely, feature-matching. Future research should continue to examine the relationships between feature-matching, familiarity-detection, and curiosity as a feeling-of-closeness, both in their shared mechanisms and potential biases. For example, feelings of familiarity during retrieval failure have been shown to bias participants into believing that they can recollect details despite being unable to do so, known as illusory recollection (e.g., Huebert et al. 2022
). Might feelings of curiosity confer a similar bias? The present experiments demonstrated associations between intense feelings of curiosity on trials associated with commission errors as opposed to omission errors. Given the associations between feelings of familiarity and illusory recollection, it may be that curiosity as a feeling-of-closeness might confer an illusory sense of being able to recollect details, as evidenced by the increased rates of commission errors. Future research should examine whether such an association does indeed exist, as it might have implications for participants’ information-seeking behaviors and when they decided to end their search efforts. If participants are highly confident in their “recollected” details, they may potentially decide to conclude their search efforts if not given the feedback that their provided answer was actually incorrect.
Although the present results were primarily interpreted within the context of the region of proximal learning framework (Metcalfe 2023
; Metcalfe et al. 2020
), an alternative way of interpreting them might be within the conflict detection approach put forward by Gruber and Fandakova
). According to this approach, curiosity arises when a conflict is detected between one’s expected outcome and the experienced outcome. This is not unlike a recent approach to déjà vu, whereby it has been argued that déjà vu may arise from the detection of conflict between an experience with a situation and the expectation regarding that situation (Urquhart et al. 2021
). That is, perhaps the expectation is that the situation is novel, yet it is experienced as familiar, leading to the detection of a conflict in need of resolution. Perhaps in the present study, this type of conflict detection is at work, leading to the information-seeking behaviors that were observed in the present study. Future research should investigate this possibility.
Finally, the present study may have relevance for the study of consciousness. Neisser et al.
) argue that memory experience
constitutes a critical piece of the puzzle of human consciousness. Déjà vu and déjà entendu represent an experiential aspect of memory, often in the absence of memory content. These phenomena (and the feelings of curiosity that they engender) involve the conscious sense or feeling of a memory, thereby potentially providing a unique window from which to explore the essence of human consciousness.