Retrieval fluency inflates perceived preparation for difficult problems.

When faced with a difficult problem, people often rely on past experiences. While remembering clearly helps us reach solutions, can retrieval also lead to misperceptions of our abilities? In three experiments, participants encountered "worst case scenarios" they likely had never experienced and that would be difficult to navigate without extensive training (e.g., bitten by snake). Learning brief tips improved problem-solving performance later, but retrieval increased feelings of preparation by an even larger margin. This gap occurred regardless of whether people thought that tips came from an expert or another participant in the study, and it did not reflect mere familiarity with the problems themselves. Instead, our results suggest that the ease experienced while remembering, or retrieval fluency, inflated feelings of preparation.

Timing matters when correcting fake news.

Countering misinformation can reduce belief in the moment, but corrective messages quickly fade from memory. We tested whether the longer-term impact of fact-checks depends on when people receive them. In two experiments (total N = 2,683), participants read true and false headlines taken from social media. In the treatment conditions, "true" and "false" tags appeared before, during, or after participants read each headline. Participants in a control condition received no information about veracity. One week later, participants in all conditions rated the same headlines' accuracy. Providing fact-checks after headlines (debunking) improved subsequent truth discernment more than providing the same information during (labeling) or before (prebunking) exposure. This finding informs the cognitive science of belief revision and has practical implications for social media platform designers.

Judging Truth.

Deceptive claims surround us, embedded in fake news, advertisements, political propaganda, and rumors. How do people know what to believe? Truth judgments reflect inferences drawn from three types of information: base rates, feelings, and consistency with information retrieved from memory. First, people exhibit a bias to accept incoming information, because most claims in our environments are true. Second, people interpret feelings, like ease of processing, as evidence of truth. And third, people can (but do not always) consider whether assertions match facts and source information stored in memory. This three-part framework predicts specific illusions (e.g., truthiness, illusory truth), offers ways to correct stubborn misconceptions, and suggests the importance of converging cues in a post-truth world, where falsehoods travel further and faster than the truth.

Neural basis of goal-driven changes in knowledge activation.

Depending on a person's goals, different aspects of stored knowledge are accessed. Decades of behavioral work document the flexible use of knowledge, but little neuroimaging work speaks to these questions. We used representational similarity analysis to investigate whether the relationship between brain activity and semantic structure of statements varied in two tasks hypothesized to differ in the degree to which knowledge is accessed: judging truth (semantic task) and judging oldness (episodic task). During truth judgments, but not old/new recognition judgments, a left-lateralized network previously associated with semantic memory exhibited correlations with semantic structure. At a neural level, people activate knowledge representations in different ways when focused on different goals. The present results demonstrate the potential of multivariate approaches in characterizing knowledge storage and retrieval, as well as the ways that it shapes our understanding and long-term memory.

Memory Meets Control in Hippocampal and Striatal Binding of Stimuli, Responses, and Attentional Control States.

The human brain encodes experience in an integrative fashion by binding together the various features of an event (i.e., stimuli and responses) into memory "event files." A subsequent reoccurrence of an event feature can then cue the retrieval of the memory file to "prime" cognition and action. Intriguingly, recent behavioral studies indicate that, in addition to linking concrete stimulus and response features, event coding may also incorporate more abstract, "internal" event features such as attentional control states. In the present study, we used fMRI in healthy human volunteers to determine the neural mechanisms supporting this type of holistic event binding. Specifically, we combined fMRI with a task protocol that dissociated the expression of event feature-binding effects pertaining to concrete stimulus and response features, stimulus categories, and attentional control demands. Using multivariate neural pattern classification, we show that the hippocampus and putamen integrate event attributes across all of these levels in conjunction with other regions representing concrete-feature-selective (primarily visual cortex), category-selective (posterior frontal cortex), and control demand-selective (insula, caudate, anterior cingulate, and parietal cortex) event information. Together, these results suggest that the hippocampus and putamen are involved in binding together holistic event memories that link physical stimulus and response characteristics with internal representations of stimulus categories and attentional control states. These bindings then presumably afford shortcuts to adaptive information processing and response selection in the face of recurring events. SIGNIFICANCE STATEMENT: Memory binds together the different features of our experience, such as an observed stimulus and concurrent motor responses, into so-called event files. Recent behavioral studies suggest that the observer's internal attentional state might also become integrated into the event memory. Here, we used fMRI to determine the brain areas responsible for binding together event information pertaining to concrete stimulus and response features, stimulus categories, and internal attentional control states. We found that neural signals in the hippocampus and putamen contained information about all of these event attributes and could predict behavioral priming effects stemming from these features. Therefore, medial temporal lobe and dorsal striatum structures appear to be involved in binding internal control states to event memories.

On Known Unknowns: Fluency and the Neural Mechanisms of Illusory Truth.

The "illusory truth" effect refers to the phenomenon whereby repetition of a statement increases its likelihood of being judged true. This phenomenon has important implications for how we come to believe oft-repeated information that may be misleading or unknown. Behavioral evidence indicates that fluency, the subjective ease experienced while processing information, underlies this effect. This suggests that illusory truth should be mediated by brain regions previously linked to fluency, such as the perirhinal cortex (PRC). To investigate this possibility, we scanned participants with fMRI while they rated the truth of unknown statements, half of which were presented earlier (i.e., repeated). The only brain region that showed an interaction between repetition and ratings of perceived truth was PRC, where activity increased with truth ratings for repeated, but not for new, statements. This finding supports the hypothesis that illusory truth is mediated by a fluency mechanism and further strengthens the link between PRC and fluency.

Fighting misinformation among the most vulnerable users.

Misinformation undermines trust in the integrity of democratic elections, the safety of vaccines, and the authenticity of footage from war zones. Social scientists have proposed many solutions to reduce individuals' demand for fake news, but it is unclear how to evaluate them. Efficacy can mean that an intervention increases discernment (the ability to distinguish true from false content), works over a delay, scales up, and engages users. I argue that experts should also consider differences in exposure prevalence before declaring success. Misleading content makes up a small fraction of the average person's news diet, but some groups are at increased risk - conservatives and older adults see and share the most fake news. Targeting the whole population (universal prevention) could concentrate benefits among the users who already see the least misinformation to begin with. In complement to these approaches, we should design interventions for the people who need them most - conservatives and older adults (selective prevention), as well as users who have already shared low-quality news (indicated prevention).

Do conspiracy theorists think too much or too little?

Conspiracy theories explain distressing events as malevolent actions by powerful groups. Why do people believe in secret plots when other explanations are more probable? On the one hand, conspiracy theorists seem to disregard accuracy; they tend to endorse mutually incompatible conspiracies, think intuitively, use heuristics, and hold other irrational beliefs. But by definition, conspiracy theorists reject the mainstream explanation for an event, often in favor of a more complex account. They exhibit a general distrust of others and expend considerable effort to find 'evidence' supporting their beliefs. In searching for answers, conspiracy theorists likely expose themselves to misleading information online and overestimate their own knowledge. Understanding when elaboration and cognitive effort might backfire is crucial, as conspiracy beliefs lead to political disengagement, environmental inaction, prejudice, and support for violence.

Linking creativity and false memory: Common consequences of a flexible memory system.

Episodic retrieval plays a functional-adaptive role in supporting divergent thinking, the ability to creatively combine different pieces of information. However, the same constructive memory process that provides a functional-adaptive benefit can also leave memory prone to error. In two experiments, we employed an individual differences approach to examine the relationship between different forms of creative thinking (divergent and convergent thinking) and false memory generation in the Deese-Roediger-McDermott paradigm. In Experiment 1, and replicating prior findings, false recognition was significantly predicted by convergent thinking performance. Critically, we also observed a novel predictive relationship between false recognition and quantitative metrics of divergent thinking performance. In Experiment 2, these findings were replicated and we further showed that false recall was predicted by quantitative metrics of divergent thinking. Our findings suggest that constructive memory processes link creative thinking with the production of memory errors.

Aging in an Era of Fake News.

Misinformation causes serious harm, from sowing doubt in modern medicine to inciting violence. Older adults are especially susceptible - they shared the most fake news during the 2016 US election. The most intuitive explanation for this pattern blames cognitive deficits. While older adults forget where they learned information, fluency remains intact and decades of accumulated knowledge helps them evaluate claims. Thus, cognitive declines cannot fully explain older adults' engagement with fake news. Late adulthood also involves social changes, including general trust, difficulty detecting lies, and less emphasis on accuracy when communicating. In addition, older adults are relative newcomers to social media, who may struggle to spot sponsored content or manipulated images. In a post-truth world, interventions should consider older adults' shifting social goals and gaps in their digital literacy.

An initial accuracy focus prevents illusory truth.

News stories, advertising campaigns, and political propaganda often repeat misleading claims, increasing their persuasive power. Repeated statements feel easier to process, and thus truer, than new ones. Surprisingly, this illusory truth effect occurs even when claims contradict young adults' stored knowledge (e.g., repeating The fastest land animal is the leopard makes it more believable). In four experiments, we tackled this problem by prompting people to behave like "fact checkers." Focusing on accuracy at exposure (giving initial truth ratings) wiped out the illusion later, but only when participants held relevant knowledge. This selective benefit persisted over a delay. Our findings inform theories of how people evaluate truth and suggest practical strategies for coping in a "post-truth world."

Knowledge supports memory retrieval through familiarity, not recollection.

Semantic memory, or general knowledge of the world, guides learning and supports the formation and retrieval of new episodic memories. Behavioral evidence suggests that this knowledge effect is supported by recollection-a more controlled form of memory retrieval generally accompanied by contextual details-to a greater degree than familiarity-a more automatic form of memory retrieval generally absent of contextual details. In the current study, we used functional magnetic resonance imaging (fMRI) to investigate the role that regions associated with recollection and familiarity play in retrieving recent instances of known (e.g., The Summer Olympic Games are held four years apart) and unknown (e.g., A flaky deposit found in port bottles is beeswing) statements. Our results revealed a surprising pattern: Episodic retrieval of known statements recruited regions associated with familiarity, but not recollection. Instead, retrieval of unknown statements recruited regions associated with recollection. These data, in combination with quicker reaction times for the retrieval of known than unknown statements, suggest that known statements can be successfully retrieved on the basis of familiarity, whereas unknown statements were retrieved on the basis of recollection. Our results provide insight into how knowledge influences episodic retrieval and demonstrate the role of neuroimaging in providing insights into cognitive processes in the absence of explicit behavioral responses.

Magical thinking decreases across adulthood.

Magical thinking, or illogical causal reasoning such as superstitions, decreases across childhood, but almost no data speak to whether this developmental trajectory continues across the life span. In four experiments, magical thinking decreased across adulthood. This pattern replicated across two judgment domains and could not be explained by age-related differences in tolerance of ambiguity, domain-specific knowledge, or search for meaning. These data complement and extend findings that experience, accumulated over decades, guides older adults' judgments so that they match, or even exceed, young adults' performance. They also counter participants' expectations, and cultural sayings (e.g., "old wives' tales"), that suggest that older adults are especially superstitious. (PsycINFO Database Record

Competing cues: Older adults rely on knowledge in the face of fluency.

Consumers regularly encounter repeated false claims in political and marketing campaigns, but very little empirical work addresses their impact among older adults. Repeated statements feel easier to process, and thus more truthful, than new ones (i.e., illusory truth). When judging truth, older adults' accumulated general knowledge may offset this perception of fluency. In two experiments, participants read statements that contradicted information stored in memory; a post-experimental knowledge check confirmed what individual participants knew. Unlike young adults, older adults exhibited illusory truth only when they lacked knowledge about claims. This interaction between knowledge and fluency extends dual-process theories of aging. (PsycINFO Database Record

Knowledge does not protect against illusory truth.

In daily life, we frequently encounter false claims in the form of consumer advertisements, political propaganda, and rumors. Repetition may be one way that insidious misconceptions, such as the belief that vitamin C prevents the common cold, enter our knowledge base. Research on the illusory truth effect demonstrates that repeated statements are easier to process, and subsequently perceived to be more truthful, than new statements. The prevailing assumption in the literature has been that knowledge constrains this effect (i.e., repeating the statement "The Atlantic Ocean is the largest ocean on Earth" will not make you believe it). We tested this assumption using both normed estimates of knowledge and individuals' demonstrated knowledge on a postexperimental knowledge check (Experiment 1). Contrary to prior suppositions, illusory truth effects occurred even when participants knew better. Multinomial modeling demonstrated that participants sometimes rely on fluency even if knowledge is also available to them (Experiment 2). Thus, participants demonstrated knowledge neglect, or the failure to rely on stored knowledge, in the face of fluent processing experiences.