Time Course of Fidelity and Contributing Factors to Long-Term Memory

Various models have been implemented to explain long-term memory (Brady, et al., 2013; Lew, et al., 2015), withsome being derived from studies of visual working memory (Bays, et al. 2009; Zhang & Luck, 2008). The implicit assumptionis that processes and mechanisms of working memory also exist in long-term memory. However, the findings of fidelity andcontributing factors are highly varied (e.g., Persaud & Hemmer, 2014; Schurgin & Flombaum, 2015) To address what happensto memory traces as they transition from visual working into long-term memory and what factors, such as prior knowledgeand guessing, contribute to the “lifespan” of long-term memory, we implemented three models: the standard remember-guessmodel, a three-component remember-guess model, and a Bayesian mixture model and evaluated these models against data froma continuous recall task. The results clarify the time course of fidelity in long-term memory and pinpoints specific factors thatcontribute to memory

The Role of Surprise in Memory: Assessing the Impact of Levels of Surprise on Children's Episodic Memory

Expectations play a critical role in children's learning. Prior studies suggest that children selectively focus on and better remember details of expectation-violating events (Stahl & Feigenson, 2017; 2019). Yet, it remains unclear whether this enhanced memory persists across varying degrees (e.g., somewhat vs. very surprising) and types of expectation violations (core-knowledge vs. schema-based violations). Adapting a surprise storybook paradigm from Foster and Keane (2019), we measure children’s (5-8 years; N=20) surprise and recognition memory for six stories that span different expectation-related domains and contain outcomes that are expectation-congruent, somewhat expectation-violating, or completely violating. While preliminary data revealed no significant difference in recognition accuracy by level of surprise, a trend towards better memory for violations of well-entrenched versus schema-based expectations was observed. This preliminary work points to potential differences in how varying types of expectations influence memory in young children and has important implications for learning

Great Expectations: Evaluating the Role of Object-Color Expectations on Visual Memory

Previous research has shown that category expectations can improve recall, by reducing absolute average error (e.g. Hut-tenlocher, et.al., 1991; Hemmer & Steyvers, 2009), particularly when expectations are consistent with studied information.However, studied information that is expectation-inconsistent may also boost memory (e.g. Sakamoto & Love, 2004).Using a cued-recall task, we manipulated the degree to which studied object-color pairs aligned with peoples (N=29)expectations to explore the role of expectations in delayed recall. Our preliminary results show greater recall accuracyfor expectation-consistent items (e.g. yellow bananas) compared to expectation-inconsistent (purple bananas), and no-expectation items (yellow toothbrushes). However, there was no difference in accuracy between expectation-inconsistentand no-expectation items, nor was there a difference between weak and strong expectation-inconsistent items (orangish-yellow and purple bananas, respectively). This preliminary work shows that in delayed recall, the benefit of categoryexpectations might not extend to instances when studied information is misaligned with those expectations

How Bizarre: Does the color bizarreness effect extend to long-term memory?

A well-known phenomenon of memory is the bizarreness effect which refers to enhanced memory for objects that are highly incongruent with people’s prior expectations. This phenomenon was recently extended into the visual domain of color, showing enhanced memory for objects paired with expectation-incongruent (or bizarre) colors. Here, we explore whether the enhanced memory for bizarre/expectation-incongruent objects extends to memory for the object-color binding and whether this binding is well-preserved long-term. Using a 4-Alternative forced choice task, we assessed memory for object colors as a function of expectation-congruency on one day and 3 days later. Our results revealed no significant difference in recognition memory for bizarre colors compared to expectation-congruent colors, and no enhanced memory for bizarre colors in long-term memory. These findings highlight conditions where the enhanced memory for expectation-incongruent information is limited, providing an interesting challenge to current mechanistic accounts of memory for expectation-related information

The Influence of Pop-Culture on Misattribution of Memory

Social media platforms provide a source for transmittinginformation that can become widely accepted. However, inthis process of transmission, information becomes susceptibleto distortion. In this study, we assessed people’s semantic(i.e., prior expectations) and recognition memory for popculture content, as a function of confidence and perceivedinformation source. In Experiment 1, we investigatedsemantic memory for ubiquitous movie quotes (e.g., thefamous Star Wars quote “Luke I am your father”). Notablythis quote is incorrect, but we found that a majority ofparticipants accepted these lure quotes as true with highconfidence and indicated they had experienced the originalsource. In Experiment 2, participants viewed the originalmovie sources before a recognition test of the quotes. Wefound that while there was some improvement, people stillpreferred the lure quote with high confidence. We discuss thefindings in terms of the strength of people’s prior expectationswhen reconstructing events from memory

Age-Related Differences in the Influence of Category Expectations on EpisodicMemory in Early Childhood

Previous research evaluating the influence of category knowl-edge on memory found that children, like adults, rely on cat-egory information to facilitate recall (Duffy, Huttenlocher, &Crawford, 2006). A model that combines category and targetinformation (Integrative) provides a superior fit to preschoolersrecall data compared to a category only (Prototype) and targetonly (Target) model (Macias, Persaud, Hemmer, & Bonawitz,in revision). Utilizing data and computational approaches fromMacias et al., (in revision), we explore whether individual andage-related differences persist in the model fits. Results re-vealed that a greater proportion of preschoolers recall was bestfit by the Prototype model and trials where children displayedindividuating behaviors, such as spontaneously labeling, werealso best fit by the Prototype model. Furthermore, the best fit-ting model varied by age. This work demonstrates a rich com-plexity and variation in recall between developmental groupsthat can be illuminated by computationally evaluating individ-ual differences

[Pre-Print] Evaluating Recall Error in Preschoolers: Category Expectations Influence Episodic Memory for Color

Despite limited memory capacity, children are exceptional learners. How might children engage in meaningful learning despite limited memory systems? Past research suggests that adults integrate category knowledge and noisy episodic traces to aid recall when episodic memory is noisy or incomplete (e.g. Hemmer & Steyvers, 2009). We suspect children utilize a similar process but integrate category and episodic traces in recall to a different degree. Here we conduct two experiments to empirically assess children’s color category knowledge (Study 1) and recall of target hue values (Study 2). In Study 1, although children’s generated hue values appear to be noisier than adults, we found no significant difference between children and adult’s generated color category means (prototypes), suggesting that preschool-aged children’s color categories are well established. In Study 2, we found that children’s (like adult’s) free recall of target hue values regressed towards color category means. We implemented three probabilistic memory models: one that combines category knowledge and specific target information (Integrative), a category only (Noisy Prototype) model, and a target only (Noisy Target) model to computationally evaluate recall performance. Consistent with previous studies with older children (Duffy, Huttenlocher, & Crawford, 2006), quantitative fits of the models to aggregate group-level data provided strong support for the Integrative process. However, at the individual subject level, a greater proportion of preschoolers’ recall was better fit by a Prototype only model. Our results provide evidence that the integration of category knowledge in episodic memory comes online early and strongly. Implications for how the greater reliance on category knowledge by preschoolers relative to adults might track with developmental shifts in relational episodic memory are discussed

Inferring the Tsimane's use of color categories from recognition memory

Knowledge of color has strong individual, environmental, and cultural differences that may systematically influence performance in cognitive tasks. For example, color knowledge has been shown to influence recall of color (Persaud & Hemmer, 2014). This manifests as a systematic regression to the mean effect, where memory is biased towards the mean hue of each universal color category. What remains unclear is whether differences, such as culture and environment, might differentially influence memory. We tested recognition memory for color in the Tsimane’ of Bolivia; an indigenous population with little or no modern schooling, whose environment is very different from industrialized societies. We found that recognition regressed towards the mean of some universal color categories, but for others was systematically biased toward neighboring categories. A cluster analysis suggested that the Tsimane’ use five underlying color categories—not the standard universals. This might be shaped by education, language and the environmen