How Prior Knowledge, Gesture Instruction, and Interference After Instruction Interact to Influence Learning of Mathematical Equivalence.

Although children learn more when teachers gesture, it is not clear how gesture supports learning. Here, we sought to investigate the nature of the memory processes that underlie the observed benefits of gesture on lasting learning. We hypothesized that instruction with gesture might create memory representations that are particularly resistant to interference. We investigated this possibility in a classroom study with 402 second- and third-grade children. Participants received classroom-level instruction in mathematical equivalence using videos with or without accompanying gesture. After instruction, children solved problems that were either visually similar to the problems that were taught, and consistent with an operational interpretation of the equal sign (interference), or visually distinct from equivalence problems and without an equal sign (control) in order to assess the role of gesture in resisting interference after learning. Gesture facilitated learning, but the effects of gesture and interference varied depending on type of problem being solved and the strategies that children used to solve problems prior to instruction. Some children benefitted from gesture, while others did not. These findings have implications for understanding the mechanisms underlying the beneficial effect of gesture on mathematical learning, revealing that gesture does not work via a general mechanism like enhancing attention or engagement that would apply to children with all forms of prior knowledge.

Factors influencing sleep-dependent consolidation: Sleep strengths memory based on encoding depth but not repetition.

Sleep consolidates declarative memory after deep but not shallow incidental encoding, but little is known about this form of consolidation. One unexplored area is the extent to which the amount of exposure to incidentally encoded information affects consolidation processes. In two experiments, we manipulated the number of times information was presented. In Experiment 1, participants encoded words either one or three times in a deep or shallow incidental encoding task and completed a surprise recognition test after sleep or wake. Sleep consolidated information after deep encoding after one and three exposures, but not after shallow encoding. In Experiment 2, we explored the relationship between sleep architecture and memory after deep encoding. There was a trend for accuracy to be negatively related to N1 sleep, and reaction time to be negatively related to slow-wave sleep for words encoded once; however, the correlations did not survive corrections for multiple comparisons. These results are discussed with respect to active and passive consolidation processes.

Consolidation without intention: Sleep strengthens veridical and gist representations of information after incidental encoding.

Sleep strengthens declarative memory, but research investigating the effect of sleep on memory for information that is not explicitly studied for a test is sparse. In two experiments, we investigated the effect of sleep on gist-based and veridical representations of incidentally encoded information. Participants rated words from Deese-Roediger-McDermott (DRM) lists in either a deep or shallow encoding task and completed a surprise memory test after either sleep or wake. In Experiment 1, words were presented in lists, in order of descending associativity with the unpresented critical lure. Memory for list words and critical lures in both encoding tasks was stronger after sleep than wake, suggesting that sleep consolidated gist-based memory. In Experiment 2, the same words were presented in a random order across the experiment to minimize gist-based processing. Sleep strengthened veridical memory for list words following deep, but not shallow, encoding and did not affect critical lures. These results suggest sleep consolidates gist and veridical representations of information after incidental encoding, and that sleep-dependent consolidation processes may depend on processes at encoding, such as overlapping context and the strength of veridical memory traces.

The ACT Predicts Academic Performance-But Why?

Scores on the ACT college entrance exam predict college grades to a statistically and practically significant degree, but what explains this predictive validity? The most obvious possibility is general intelligence-or psychometric "g". However, inconsistent with this hypothesis, even when independent measures of g are statistically controlled, ACT scores still positively predict college grades. Here, in a study of 182 students enrolled in two Introductory Psychology courses, we tested whether pre-course knowledge, motivation, interest, and/or personality characteristics such as grit and self-control could explain the relationship between ACT and course performance after controlling for g. Surprisingly, none could. We speculate about what other factors might explain the robust relationship between ACT scores and academic performance.

Physical activity and sleep moderate the relationship between stress and screen time in college-aged adults.

For undergraduate students, excessive screen time is associated with poorer mental health and greater perceived stress. Objective: The purpose of the present investigation was to determine the potential moderating influence of physical activity and sleep on the relationship between screen time and stress. Participants & Methods: A cross-sectional sample of 513 undergraduate students between Fall 2017 & Spring 2020 were given a questionnaire to assess perceived stress level, physical activity engagement, screen time, and sleep. Results: Stepwise hierarchical regression analyses identified that screen time, sleep, and the three-way interaction between screen time, sleep, and physical activity were associated with stress. Post-hoc decomposition revealed that higher levels of physical activity and sleep both mitigated the relationship between screen time and stress. Conclusions: Findings suggest that modifiable health behaviors such as physical activity and sleep may be important factors for managing the negative effects of screen time on stress in college-aged adults.

HighlightsExcessive screen time is associated with higher levels of stress.Cross-sectional sample of 513 college-aged young adults.Adiposity and aerobic fitness were unrelated to stress.In high active individuals, screen time is unrelated to stress.In low active individuals, greater sleep attenuates the screen time-stress relationship.

Eyewitness confidence may not be ready for the courts: a reply to Wixted et al.

Wixted et al. (in press. Doing right by the eyewitness evidence: A response to Berkowitz et al. Memory) remind us that they are aware of some conditions in which confidence does not trump all but suggest that initial high-confidence errors should be rare. In this reply, we draw attention to new lab research that continues to cast doubt on the value of an initial eyewitness identification made with high confidence. Additional data from field studies of police lineups lead us to conclude that it is far too risky in real-world cases to assume that eyewitnesses who have high initial confidence are also highly accurate. As a final point, we dispute Wixted et al.'s interpretation of "initial low confidence" in the DNA exoneration cases.

Convicting with confidence? Why we should not over-rely on eyewitness confidence.

Eyewitness memory researchers have recently devoted considerable attention to eyewitness confidence. While there is strong consensus that courtroom confidence is problematic, we now recognise that an eyewitness's initial confidence in their first identification - in certain contexts - can be of value. A few psychological scientists, however, have confidently, but erroneously claimed that in real-world cases, eyewitness initial confidence is the most important indicator of eyewitness accuracy, trumping all other factors that might exist in a case. This claim accompanies an exaggeration of the role of eyewitnesses' "initial confidence" in the DNA exoneration cases. Still worse, overstated claims about the confidence-accuracy relationship, and eyewitness memory, have reached our top scientific journals, news articles, and criminal cases. To set the record straight, we review what we actually know and do not know about the "initial confidence" of eyewitnesses in the DNA exoneration cases. Further reasons for skepticism about the value of the confidence-accuracy relationship in real-world cases come from new analyses of a separate database, the National Registry of Exonerations. Finally, we review new research that reveals numerous conditions wherein eyewitnesses with high initial confidence end up being wrong.

Slow-wave sleep during a brief nap is related to reduced cognitive deficits during sleep deprivation.

Sleeping for a short period (i.e. napping) may help mitigate impairments in cognitive processing caused by sleep deprivation, but there is limited research on effects of brief naps in particular. Here, we tested the effect of a brief nap opportunity (30- or 60-min) during a period of sleep deprivation on two cognitive processes with broad scope, placekeeping and vigilant attention. In the evening, participants (N = 280) completed a placekeeping task (UNRAVEL) and a vigilant attention task (Psychomotor Vigilance Task [PVT]) and were randomly assigned to either stay awake overnight or sleep at home. Sleep-deprived participants were randomly assigned to receive either no nap opportunity, a 30-min opportunity, or a 60-min opportunity. Participants who napped were set up with polysomnography. The next morning, sleep participants returned, and all participants completed UNRAVEL and the PVT. Sleep deprivation impaired performance on both tasks, but nap opportunity did not reduce the impairment, suggesting that naps longer than those tested may be necessary to cause group differences. However, in participants who napped, more time spent in slow-wave sleep (SWS) was associated with reduced performance deficits on both tasks, effects we interpret in terms of the role of SWS in alleviating sleep pressure and facilitating memory consolidation.

Caffeine selectively mitigates cognitive deficits caused by sleep deprivation.

Sleep deprivation impairs a wide range of cognitive processes, but the precise mechanism underlying these deficits is unclear. One prominent proposal is that sleep deprivation impairs vigilant attention, and that impairments in vigilant attention cause impairments in cognitive tasks that require attention. Here, we test this theory by studying the effects of caffeine on visual vigilant attention and on placekeeping, a cognitive control process that plays a role in procedural performance, problem solving, and other higher order tasks. In the evening, participants (N = 276) completed a placekeeping task (UNRAVEL) and a vigilant attention task (the Psychomotor Vigilance Task [PVT]) and were then randomly assigned to either stay awake overnight in the laboratory or sleep at home. In the morning, participants who slept returned to the lab, and all participants consumed a capsule that contained either 200 mg of caffeine or placebo. After an absorption period, all participants completed UNRAVEL and PVT again. Sleep deprivation impaired performance on both tasks, replicating previous work. Caffeine counteracted this impairment in vigilant attention but did not significantly affect placekeeping for most participants, though it did reduce the number of sleep-deprived participants who failed to maintain criterion accuracy. These results suggest that sleep deprivation impairs placekeeping directly through a causal pathway that does not include visual vigilant attention, a finding that has implications for intervention research and suggests that caffeine has limited potential to reduce procedural error rates in occupational settings. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Is it worth it? The costs and benefits of bringing a laptop to a university class.

Students often bring laptops to university classes, however, they do not limit their laptop use to class-related activity. Off-task laptop use occurs frequently in university classrooms and this use negatively impacts learning. The present study addresses whether potential benefits of class-related laptop use might mitigate the costs of off-task laptop activity. We used tracking software to monitor both class-related and off-task laptop use by undergraduate students enrolled in an introductory psychology course, and we observed how types of laptop use related to course performance. We found a positive correlation between class-related use and exam scores that was driven by viewing lecture slides during class. We also found a negative correlation between off-task laptop use and exam scores, but class-related activities did not predict an increase in off-task use. Thus, for students who constrain their laptop use to class-related activity, the benefits outweigh the costs. While a laptop may be beneficial for some, it is unclear which students are able to constrain themselves to class-related activities and whether the benefits of class-related laptop use obtained by slide viewing could be achieved by other means. Thus, students and educators should carefully consider the costs and benefits of laptop use in the classroom.

Gesture during math instruction specifically benefits learners with high visuospatial working memory capacity.

BACKGROUND: Characteristics of both teachers and learners influence mathematical learning. For example, when teachers use hand gestures to support instruction, students learn more than others who learn the same concept with only speech, and students with higher working memory capacity (WMC) learn more rapidly than those with lower WMC. One hypothesis for the effect of gesture on math learning is that gestures provide a signal to learners that can reduce demand on working memory resources during learning. However, it is not known what sort of working memory resources support learning with gesture. Gestures are motoric; they co-occur with verbal language and they are perceived visually. METHODS: In two studies, we investigated the relationship between mathematical learning with or without gesture and individual variation in verbal, visuospatial, and kinesthetic WMC. Students observed a videotaped lesson in a novel mathematical system that either included instruction with both speech and gesture (Study 1) or instruction with only speech (Study 2). After instruction, students solved novel problems in the instructed system and transfer problems in a related system. Finally, students completed verbal, visuospatial, and kinesthetic working memory assessments. RESULTS: There was a positive relationship between visuospatial WMC and math learning when gesture was present, but no relationship between visuospatial WMC and math learning when gesture was absent. Rather, when gesture was absent, there was a relationship between verbal WMC and math learning. CONCLUSION: Providing gesture during instruction appears to change the cognitive resources recruited when learning a novel math task.

Shaping perceptual learning of synthetic speech through feedback.

Listeners exposed to accented speech must adjust how they map between acoustic features and lexical representations such as phonetic categories. A robust form of this adaptive perceptual learning is learning to perceive synthetic speech where the connections between acoustic features and phonetic categories must be updated. Both implicit learning through mere exposure and explicit learning through directed feedback have previously been shown to produce this type of adaptive learning. The present study crosses implicit exposure and explicit feedback with the presence or absence of a written identification task. We show that simple exposure produces some learning, but explicit feedback produces substantially stronger learning, whereas requiring written identification did not measurably affect learning. These results suggest that explicit feedback guides learning of new mappings between acoustic patterns and known phonetic categories. We discuss mechanisms that may support learning via implicit exposure.

Effects of total sleep deprivation on procedural placekeeping: More than just lapses of attention.

Total sleep deprivation (TSD) impairs attention as well as higher-order cognitive processes. Because attention is a core component of many tasks, it may fully mediate the effect of sleep deprivation on higher-order processes. We examined this possibility using the Psychomotor Vigilance Task as a measure of attention and the UNRAVEL task as a measure of placekeeping, a higher-order process that involves memory operations and supports performance in a wide range of complex tasks. A large sample of participants (N = 138 contributing data) performed the Psychomotor Vigilance Task and UNRAVEL under rested or sleep-deprived conditions. TSD impaired placekeeping generally and memory maintenance processes specifically, above and beyond the effect of participants' attentional state. The results suggest that TSD may impair a range of higher-order cognitive processes directly, not just fundamental processes such as attention, and that interventions that benefit attention may have limited scope. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Negativity bias in false memory: moderation by neuroticism after a delay.

The negativity bias is the tendency for individuals to give greater weight, and often exhibit more rapid and extreme responses, to negative than positive information. Using the Deese-Roediger-McDermott illusory memory paradigm, the current study sought to examine how the negativity bias might affect both correct recognition for negative and positive words and false recognition for associated critical lures, as well as how trait neuroticism might moderate these effects. In two experiments, participants studied lists of words composed of semantic associates of an unpresented word (the critical lure). Half of the lists were comprised of positive words and half were comprised of negative words. As expected, individuals remembered negative list words better than positive list words, consistent with a negativity bias in correct recognition. When tested immediately (Experiment 1), individuals also exhibited greater false memory for negative versus positive critical lures. When tested after a 24-hr delay (Experiment 2), individuals higher in neuroticism maintained greater false memory for negative versus positive critical lures, but those lower in neuroticism showed no difference in false memory between negative and positive critical lures. Possible mechanisms and implications for mental health disorders are discussed.

Effects of sleep deprivation on procedural errors.

In a large sample (N = 234), we tested effects of 24-hr of sleep deprivation on error rates in a procedural task that requires memory maintenance of task-relevant information. In the evening, participants completed the task under double-blind conditions and then either stayed awake in the lab overnight or slept at home. In the morning, participants completed the task again. Sleep-deprived participants were more likely to suffer a general breakdown in ability (or willingness) to meet a modest accuracy criterion they had met the night before. Among sleep-deprived participants who could still perform the task, error rates were elevated, and errors reflecting memory failures increased with time-on-task. The results suggest that sleep-deprived individuals should not perform procedural tasks associated with interruptions and costly errors-or, if they must, they should perform such tasks only for short periods. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Sleep and eyewitness memory: Fewer false identifications after sleep when the target is absent from the lineup.

Inaccurate eyewitness identifications are the leading cause of known false convictions in the United States. Moreover, improving eyewitness memory is difficult and often unsuccessful. Sleep consistently strengthens and protects memory from interference, particularly when a recall test is used. However, the effect of sleep on recognition memory is more equivocal. Eyewitness identification tests are often recognition based, thus leaving open the question of how sleep affects recognition performance in an eyewitness context. In the current study, we investigated the effect of sleep on eyewitness memory. Participants watched a video of a mock-crime and attempted to identify the perpetrator from a simultaneous lineup after a 12-hour retention interval that either spanned a waking day or night of sleep. In Experiment 1, we used a target-present lineup and, in Experiment 2, we used a target-absent lineup in order to investigate correct and false identifications, respectively. Sleep reduced false identifications in the target-absent lineup (Experiment 2) but had no effect on correct identifications in the target-present lineup (Experiment 1). These results are discussed with respect to memory strength and decision making strategies.

Logged In and Zoned Out.

Laptop computers are widely prevalent in university classrooms. Although laptops are a valuable tool, they offer access to a distracting temptation: the Internet. In the study reported here, we assessed the relationship between classroom performance and actual Internet usage for academic and nonacademic purposes. Students who were enrolled in an introductory psychology course logged into a proxy server that monitored their online activity during class. Past research relied on self-report, but the current methodology objectively measured time, frequency, and browsing history of participants' Internet usage. In addition, we assessed whether intelligence, motivation, and interest in course material could account for the relationship between Internet use and performance. Our results showed that nonacademic Internet use was common among students who brought laptops to class and was inversely related to class performance. This relationship was upheld after we accounted for motivation, interest, and intelligence. Class-related Internet use was not associated with a benefit to classroom performance.

The Association between Physical Activity During the Day and Long-Term Memory Stability.

Despite positive associations between chronic physical activity and memory; we have little understanding of how best to incorporate physical activity during the day to facilitate the consolidation of information into memory, nor even how time spent physically active during the day relates to memory processes. The purpose of this investigation was to examine the relation between physical activity during the day and long-term memory. Ninety-two young adults learned a list of paired-associate items and were tested on the items after a 12-hour interval during which heart rate was recorded continuously. Although the percentage of time spent active during the day was unrelated to memory, two critical physical activity periods were identified as relating to the maintenance of long-term memory. Engaging in physical activity during the period 1 to 2-hours following the encoding of information was observed to be detrimental to the maintenance of information in long-term memory. In contrast, physical activity during the period 1-hour prior to memory retrieval was associated with superior memory performance, likely due to enhanced retrieval processing. These findings provide initial evidence to suggest that long-term memory may be enhanced by more carefully attending to the relative timing of physical activity incorporated during the day.

Sleep deprivation and false confessions.

False confession is a major contributor to the problem of wrongful convictions in the United States. Here, we provide direct evidence linking sleep deprivation and false confessions. In a procedure adapted from Kassin and Kiechel [(1996) Psychol Sci 7(3):125-128], participants completed computer tasks across multiple sessions and repeatedly received warnings that pressing the "Escape" key on their keyboard would cause the loss of study data. In their final session, participants either slept all night in laboratory bedrooms or remained awake all night. In the morning, all participants were asked to sign a statement, which summarized their activities in the laboratory and falsely alleged that they pressed the Escape key during an earlier session. After a single request, the odds of signing were 4.5 times higher for the sleep-deprived participants than for the rested participants. These findings have important implications and highlight the need for further research on factors affecting true and false confessions.

General intelligence predicts memory change across sleep.

Psychometric intelligence (g) is often conceptualized as the capability for online information processing but it is also possible that intelligence may be related to offline processing of information. Here, we investigated the relationship between psychometric g and sleep-dependent memory consolidation. Participants studied paired-associates and were tested after a 12-hour retention interval that consisted entirely of wake or included a regular sleep phase. We calculated the number of word-pairs that were gained and lost across the retention interval. In a separate session, participants completed a battery of cognitive ability tests to assess g. In the wake group, g was not correlated with either memory gain or memory loss. In the sleep group, we found that g correlated positively with memory gain and negatively with memory loss. Participants with a higher level of general intelligence showed more memory gain and less memory loss across sleep. Importantly, the correlation between g and memory loss was significantly stronger in the sleep condition than in the wake condition, suggesting that the relationship between g and memory loss across time is specific to time intervals that include sleep. The present research suggests that g not only reflects the capability for online cognitive processing, but also reflects capability for offline processes that operate during sleep.