When Learning Disturbs Memory - Temporal Profile of Retroactive Interference of Learning on Memory Formation

The role of memory in counterfactual valuation

Value-based decisions are often guided by past experience. If a choice led to a good outcome, we are more likely to repeat it. This basic idea is well-captured by reinforcement-learning models. However, open questions remain about how we assign value to options we did not choose and which we therefore never had the chance to learn about directly. One solution to this problem is proposed by policy gradient reinforcement-learning models; these do not require direct learning of value, instead optimizing choices according to a behavioral policy. For example, a logistic policy predicts that if a chosen option was rewarded, the unchosen option would be deemed less desirable. Here, we test the relevance of these models to human behavior and explore the role of memory in this phenomenon. We hypothesize that a policy may emerge from an associative memory trace formed during deliberation between choice options. In a preregistered study (n = 315) we show that people tend to invert the value of unchosen options relative to the outcome of chosen options, a phenomenon we term inverse decision bias. The inverse decision bias is correlated with memory for the association between choice options; moreover, it is reduced when memory formation is experimentally interfered with. Finally, we present a new memory-based policy gradient model that predicts both the inverse decision bias and its dependence on memory. Our findings point to a significant role of associative memory in valuation of unchosen options and introduce a new perspective on the interaction between decision-making, memory, and counterfactual reasoning. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Presenting rose odor during learning, sleep and retrieval helps to improve memory consolidation: a real-life study

Improving our learning abilities is important for numerous aspects of our life. Several studies found beneficial effects of presenting cues (odor or sounds) during learning and during sleep for memory performance. A recent study applying a real-life paradigm indicated that additional odor cueing during a Final Test can further increase this cueing effect. The present online study builds on these findings with the following questions: (1) Can we replicate beneficial memory effects of additional odor cueing during tests? (2) How many odor cueing learning sessions and odor cueing nights of sleep maximize the learning success? (3) Can odor cueing also reduce the amount of forgetting over time? 160 Participants learned 40 German Japanese word pairs in four groups with separate experimental conditions over three days. Group N received no odor during the whole study. Group LS received odor cueing during learning and sleep, group LT during learning and testing and group LST during learning, sleep and testing. Participants performed intermediate tests after each learning session plus three final tests 1, 7 and 28 days after the last learning session. Results: (1) Group LST learned 8.5% more vocabulary words than the other groups overall. (2) This odor cueing effect increased across the three days of cued learning. (3) We found no clear evidence for effects of odor cueing on the forgetting dynamics. Our findings support the notion of a beneficial effect of odor cueing. They further suggest to use at least 3 days and nights of odor cueing. Overall, this study indicates that there is an easy, efficient and economical way to enhance memory performance in daily life.

Elementary math in elementary school: the effect of interference on learning the multiplication table

Memorizing the multiplication table is a major challenge for elementary school students: there are many facts to memorize, and they are often similar to each other, which creates interference in memory. Here, we examined whether learning would improve if the degree of interference is reduced, and which memory processes are responsible for this improvement. In a series of 16 short training sessions over 4 weeks, first-grade children learned 16 multiplication facts-4 facts per week. In 2 weeks the facts were dissimilar from each other (low interference), and in 2 control weeks the facts were similar (high interference). Learning in the low-similarity, low-interference weeks was better than in the high-similarity weeks. Critically, this similarity effect originated in the specific learning context, i.e., the grouping of facts to weeks, and could not be explained as an intrinsic advantage of certain facts over others. Moreover, the interference arose from the similarity between facts in a given week, not from the similarity to previously learned facts. Similarity affected long-term memory-its effect persisted 7 weeks after training has ended; and it operated on long-term memory directly, not via the mediation of working memory. Pedagogically, the effectiveness of the low-interference training method, which is dramatically different from currently used pedagogical methods, may pave the way to enhancing how we teach the multiplication table in school.

Memory Consolidation Is Similar in Waking and Sleep

Purpose of Review

I review the current status of the hypothesis that sleep is critically involved in memory consolidation and conclude that there are major methodological problems with the studies used to support this hypothesis.

Recent Findings

Memory consolidation is similar in quiet waking and sleep (Humiston GB, Tucker MA, Summer T, Wamsley EJ. Sci Rep 18;9(1):19345, 2019), and suppression of REM sleep for long periods is compatible with learning and highly adaptive behavior (Lyamin OI, Korneva SM, Obukhova ED, Mukhametov LM, Siegel JM. Dokl Biol Sci 463:211-4, 2015; Lyamin OI, Kosenko PO, Korneva SM, Vyssotski AL, Mukhametov LM, Siegel JM. Current Biology 28(12):2000-5, 2018); despite their considerable abilities to navigate and remember, African elephants have very small amount of sleep, and learning interference effects have not been adequately controlled for in studies purporting to show sleep-dependent memory consolidation (Sosic-Vasic Z, Hille K, Kroner J, Spitzer M, Kornmeier J. Frontiers in psychology 9:82, 2018; Yonelinas AP, Ranganath C, Ekstrom AD, Wiltgen BJ. Nat Rev Neurosci 20(6):364-75, 2019).

Summary

Memory consolidation clearly occurs in both sleep and waking. Whether, and the extent to which, consolidation might differ in these two states has not been conclusively determined.

Difficulties in retrieval multiplication facts: The case of interference to reconsolidation

OBJECTIVES

Many students have difficulties in retrieving multiplication facts from memory. The aim of the present study was to test the difficulty in retrieval of multiplication facts from the perspective of the reconsolidation of long-term memory phase, which has been found to be sensitive to interferences.

METHODS

Students learned multiplication facts and then received a reminder, which led to reactivation and reconsolidation. After the reminder, additional multiplication facts (interference) were learned and memory was tested.

RESULTS

Students who received both a reminder and interference during reconsolidation showed no significant improvement in retrieving multiplication facts from memory, whereas Students who received either a reminder or additional multiplication facts (interference) exhibited a better performance in retrieval.

CONCLUSIONS

These results indicate, for the first time, that the reconsolidation phase is sensitive to interferences in mathematical declarative memory content. The findings indicate additional possible causes for difficulties in retrieval of multiplication facts in class.

Do sequential lineups impair underlying discriminability?

Debate regarding the best way to test and measure eyewitness memory has dominated the eyewitness literature for more than 30 years. We argue that resolution of this debate requires the development and application of appropriate measurement models. In this study we developed models of simultaneous and sequential lineup presentations and used these to compare these procedures in terms of underlying discriminability and response bias, thereby testing a key prediction of diagnostic feature detection theory, that underlying discriminability should be greater for simultaneous than for stopping-rule sequential lineups. We fit the models to the corpus of studies originally described by Palmer and Brewer (2012, Law and Human Behavior, 36(3), 247-255), to data from a new experiment and to eight recent studies comparing simultaneous and sequential lineups. We found that although responses tended to be more conservative for sequential lineups there was little or no difference in underlying discriminability between the two procedures. We discuss the implications of these results for the diagnostic feature detection theory and other kinds of sequential lineups used in current jurisdictions.

How odor cues help to optimize learning during sleep in a real life-setting

Effortless learning during sleep is everybody’s dream. Several studies found that presenting odor cues during learning and selectively during slow wave sleep increases learning success. The current study extends previous research in three aspects to test for optimization and practical applicability of this cueing effect: We (1) performed a field study of vocabulary-learning in a regular school setting, (2) stimulated with odor cues during the whole night without sleep monitoring, and (3) applied the odor additionally as retrieval cue in a subsequent test. We found an odor cueing effect with comparable effect sizes (d between 0.6 and 1.2) as studies with sleep monitoring and selective cueing. Further, we observed some (non-significant) indication for a further performance benefit with additional cueing during the recall test. Our results replicate previous findings and provide important extensions: First, the odor effect also works outside the lab. Second, continuous cueing at night produces similar effect sizes as a study with selective cueing in specific sleep stages. Whether odor cueing during memory recall further increases memory performance hast to be shown in future studies. Overall, our results extend the knowledge on odor cueing effects and provide a realistic practical perspective on it.

The Effects of Acute Exercise on Retroactive Memory Interference

PURPOSE

Retroactive interference involves the disruption of previously encoded information from newly learned information and thus may impair the consolidation of long-term memory. The objective of this study was to evaluate whether acute exercise can attenuate retroactive memory interference.

DESIGN

Three experimental studies were employed. Experiment 1 employed a between-subject randomized control trial (RCT) involving moderate-intensity walking (15 minutes). Experiment 2 employed a between-subject RCT involving high-intensity jogging (15 minutes). Experiment 3 employed a within-subject RCT involving moderate-intensity walking (15 minutes).

SETTING

University setting.

PARTICIPANTS

One hundred twelve young adults.

MEASURES

After exercise, memory interference was evaluated from an episodic word-list memory task, involving the recall of 2 word lists.

RESULTS

The pooled effect size (standard difference in means: -0.35; 95% confidence interval: -0.64 to -0.06) across the 3 experiments was statistically significant (P = .01).

CONCLUSION

We provide suggestive evidence that acute, short-duration exercise may help attenuate a retroactive memory interference effect. Implications of these findings for exercise to improve memory and attenuate memory decay are discussed.