Algorithmic Spaced Retrieval Enhances Long-Term Memory in Alzheimer Disease: Case-Control Pilot Study.

BACKGROUND: Spaced retrieval is a learning technique that involves engaging in repeated memory testing after increasingly lengthy intervals of time. Spaced retrieval has been shown to improve long-term memory in Alzheimer disease (AD), but it has historically been difficult to implement in the everyday lives of individuals with AD. OBJECTIVE: This research aims to determine, in people with mild cognitive impairment (MCI) due to AD, the efficacy and feasibility of a mobile app that combines spaced retrieval with a machine learning algorithm to enhance memory retention. Specifically, the app prompts users to answer questions during brief daily sessions, and a machine learning algorithm tracks each user's rate of forgetting to determine the optimal spacing schedule to prevent anticipated forgetting. METHODS: In this pilot study, 61 participants (young adults: n=21, 34%; healthy older adults: n=20, 33%; people with MCI due to AD: n=20, 33%) used the app for 4 weeks to learn new facts and relearn forgotten name-face associations. Participation during the 4-week period was characterized by using the app once per day to answer 15 questions about the facts and names. After the 4-week learning phase, participants completed 2 recognition memory tests approximately 1 week apart, which tested memory for information they had studied using the app as well as information they had not studied. RESULTS: After using the mobile app for 1 month, every person with MCI due to AD demonstrated improvements in memory for new facts that they had studied via the app compared to baseline (P<.001). All but one person with MCI due to AD (19/20, 95%) showed improvements of more than 10 percentage points, comparable to the improvements shown by young adults and healthy older adults. Memory for name-face associations was similarly improved for all participant groups after using the app but to a lesser degree. Furthermore, for both new facts and name-face associations, we found no memory decay for any participant group after they took a break of approximately 1 week from using the app at the end of the study. Regarding usability, of the 20 people with MCI due to AD, 16 (80%) self-adhered to the app's automated practice schedule, and half of them (n=10, 50%) expressed an interest in continuing to use it. CONCLUSIONS: These results demonstrate early evidence that spaced retrieval mobile apps are both feasible for people with early-stage AD to use in their everyday lives and effective for supporting memory retention of recently learned facts and name-face associations.

Are witnesses able to avoid highly accessible misinformation? Examining the efficacy of different warnings for high and low accessibility postevent misinformation.

The reliability of eyewitness memory continues to be an area of concern, particularly in situations that involve conflicting sources of information (e.g., the misinformation effect; Loftus et al., 1978, Journal of Experimental Psychology: Human Learning and Memory, 4[1], 19-31). To mitigate the negative effects of misinformation, researchers have examined the efficacy of warnings that highlight the unreliability of postevent information. However, warnings have proven less effective for highly accessible misinformation (Eakin et al., 2003, Journal of Experimental Psychology: Learning, Memory, and Cognition, 29[5], 813-825). In the present study, we examined the effects of different types of warnings for low accessibility misinformation in a standard single test misinformation paradigm, and highly accessible misinformation in a repeated testing misinformation paradigm (Chan et al., 2009, Psychological Science, 20[1], 66-73). We modeled these warnings after Eakin et al. (2003) to include both general warnings and specific question-by-question warnings. We found that warnings were effective in both types of misinformation paradigms. Additionally, memory accuracy in situations where participants were exposed to misleading information was improved when specific and general warnings were combined. We argue that both retrieval blocking of low accessibility items and enhanced contextual discrimination account for these findings.

Visual category learning: Navigating the intersection of rules and similarity.

Visual categorization is fundamental to expertise in a wide variety of disparate domains, such as radiology, art history, and quality control. The pervasive need to master visual categories has served as the impetus for a vast body of research dedicated to exploring how to enhance the learning process. The literature is clear on one point: no category learning technique is always superior to another. In the present review, we discuss how two factors moderate the efficacy of learning techniques. The first, category similarity, refers to the degree of featural overlap of exemplars. The second moderator, category type, concerns whether the features that define category membership can be mastered through learning processes that are implicit/non-verbal (information-integration categories) or explicit/verbal (rule-based categories). The literature on each moderator has been conducted almost entirely in isolation, such that their potential interaction remains underexplored. We address this gap in the literature by reviewing empirical and theoretical evidence that these two moderators jointly influence the efficacy of learning techniques.

Acute stress enhances general-knowledge semantic memory.

Acute psychological stress consistently impairs episodic memory, which consists of memory for events that are associated with a specific context. However, researchers have not yet established how stress influences semantic memory, which consists of general knowledge that is devoid of context. In the present study, participants either underwent stress induction or a control task prior to taking a trivia test that was designed to measure semantic memory. In contrast to the wealth of prior research on episodic memory, we found that stress enhanced semantic-memory retrieval. Supporting this finding, higher cortisol reactivity to stress was associated with better performance on the trivia test. Together with the results from previous studies of episodic memory, our findings suggest that stress differentially influences memory retrieval, depending on the degree to which the retrieval of a given memory relies on medial-temporal, neocortical, and striatal brain regions.