The Temporal Effects of Acute Exercise on Episodic Memory Function: Systematic Review with Meta-Analysis

Tai Chi-Induced Exosomal LRP1 is Associated With Memory Function and Hippocampus Plasticity in aMCI Patients

OBJECTIVES

The study was designed to identify the potential peripheral processes of circulating exosome in response to Tai Chi (TC) exercise and the possibility of its loaded cargos in mediating the effects of TC training on cognitive function among older adults with amnestic mild cognitive impairment (aMCI).

DESIGN, SETTING, AND PARTICIPANTS

This was a multicenter randomized controlled trial. One hundred community-dwelling old adults with aMCI were randomly assigned (1:1) to experimental (n = 50) and control groups (n = 50).

INTERVENTION

The experimental group participated in TC exercise 5 times/week, with each session lasting 60 minutes for 12 weeks. Both experimental and control groups received health education every 4 weeks.

MEASUREMENTS

The primary outcome was global cognitive function. Neurocognitive assessments, MRI examination, and large-scale proteomics analysis of peripheric exosome were conducted at baseline and after 12-week training. Outcome assessors and statisticians were blinded to group allocation.

RESULTS

A total of 96 participants (96%) completed all outcome measurements. TC training improved global cognitive function (adjusted mean difference [MD] = 1.9, 95%CI 0.93-2.87, p <0.001) and memory (adjusted MD = 6.42, 95%CI 2.09-10.74, p = 0.004), increased right hippocampus volume (adjusted MD = 88.52, 95%CI 13.63-163.4, p = 0.021), and enhanced rest state functional connectivity (rsFC) between hippocampus and cuneus, which mediated the group effect on global cognitive function (bootstrapping CIs: [0.0208, 1.2826], [0.0689, 1.2211]) and verbal delay recall (bootstrapping CI: [0.0002, 0.6277]). Simultaneously, 24 differentially expressed exosomal proteins were detected in tandem mass tag-labelling proteomic analysis. Of which, the candidate protein low-density lipoprotein receptor-related protein 1 (LRP1) was further confirmed by parallel reaction monitoring and ELISA. Moreover, the up-regulated LRP1 was both positively associated with verbal delay recall and rsFC (left hippocampus-right cuneus).

CONCLUSION

TC promotes LRP1 release via exosome, which was associated with enhanced memory function and hippocampus plasticity in aMCI patients. Our findings provided an insight into potential therapeutic neurobiological targets focusing on peripheric exosome in respond to TC exercise.

A mechanistic understanding of cognitive performance deficits concurrent with vigorous intensity exercise

This study aimed to evaluate whether cerebral oxygenation of the prefrontal cortex and associative-dissociative focus while completing the task mediate changes in cognition during exercise. Seventy-five young college-aged adults participated in this within-subjects randomized cross-over two-arm experimental design. During each session, participants completed a Stroop task four separate times: at baseline, two times during the exercise session, and at post-test. The experimental arm session involved participants cycling first at a moderate intensity, followed by cycling at a vigorous intensity. The active control arm session involved participants cycling at a very light intensity to ensure any effects were attributable to the level of exertion rather than the control of motor coordination. Cerebral oxygenation of the prefrontal cortex was assessed using fNIRS, while associate-dissociate attention was assessed using a self-report scale to provide insight into two hypothesized mechanisms which may contribute to alterations in cognition during exercise. Replicating well-established findings, results showed that during vigorous-intensity exercise, accuracy rates decreased for the most cognitively demanding conditions of the Stroop task, while reaction times were generally shorter compared to baseline. Neither shifting of attention in response to the dual-task nor prefrontal cortex oxygenation were observed to mediate cognitive deficits associated with vigorous exercise.

Higher intensity exercise after encoding is more conducive to episodic memory retention than lower intensity exercise: A field study in endurance runners

An acute bout of exercise in the moments after learning benefits the retention of new memories. This finding can be explained, at least partly, through a consolidation account: exercise provides a physiological state that is conducive to the early stabilisation of labile new memories, which supports their retention and subsequent retrieval. The modification of consolidation through non-invasive exercise interventions offers great applied potential. However, it remains poorly understood whether effects of exercise translate from the laboratory to naturalistic settings and whether the intensity of exercise determines the effect in memory. To this end, adult endurance runners were recruited as participants and completed two study sessions spaced two weeks apart. In each session, participants were presented with a list of words and asked to recall them on three occasions: (i) immediately following their presentation, (ii) after a 30-minute retention interval, and (iii) after 24 hours. Crucially, the 30-minute retention interval comprised our experimental manipulation: higher intensity exercise (running) in the first session and lower intensity exercise (walking) in the second, both completed in a naturalistic setting around participants' existing physical activity training programmes. Exertion was recorded through heart rate and rate of perceived exertion data. Alertness, mood, and arousal ratings were also collected before and after the 30-minute retention interval. Immediate memory for the two wordlists was matched, but participants retained significantly more words after 30 minutes and 24 hours when encoding was followed by higher than lower intensity exercise. Exertion data revealed that participants experienced vigorous and light exercise in the higher and lower intensity conditions, respectively. Significant improvements in alertness, mood, and arousal were observed following both exercise conditions, but especially in the higher intensity condition. These outcomes reveal that experiencing higher intensity physical activity in the field is conducive to declarative memory retention, possibly because it encourages consolidation.

Effects of word presentation during treadmill walking on episodic memory and gait

Entrainment emerges when oscillatory movements synchronize with environmental stimuli processing. The purpose of this experiment was to assess how cognitive-motor entrainment during a dual-task would influence the quality of gait and affect episodic long-term memory. Twenty-one participants (22.56 y/o; 64 % F) walked at preferred paces while listening to 40-item word lists. In separate sessions, unique word lists were presented predictably on every fourth stride, unpredictably related to stepping, or predictably while standing. Memory tests administered 24-hr after encoding revealed that predictable word presentation led to better free-recall performance than unpredicted (p = .044); recognition memory was not impacted. Gait phase parameters during the predicted condition were more stable than the unpredicted condition or baseline assessments. Cognitive-motor entrainment may alleviate dual-task costs and enhance memory retention.

Exercise and Acute Cognitive Enhancement

Substantial research has explored the effects of a single session of exercise on cognitive performance. Meta-analytic reviews provide summary statistics relative to these effects when the cognitive task is performed while exercising and when performed after exercise. When performed concomitantly the effects of exercise are typically small or negative with the exception of moderate effects for speed of cognitive performance during moderate intensity exercise. When cognitive performance is assessed following the cessation of exercise, the effects are typically positive. When considering the effects following exercise, most studies have focused on executive function and episodic memory as the cognitive outcomes of interest with meta-analyses supporting small-to-moderate benefits. When potential moderators related to exercise parameters or participants characteristics are examined, results suggest that 20 minutes of moderate to vigorous intensity exercise consistently benefits performance with larger effects evident for executive function tasks with higher cognitive demands, for long-term memory tasks when exercise is performed prior to information encoding, and when considering individuals with lower initial cognitive performance levels. These observed benefits are likely due to the impacts acute exercise can have on physiological arousal, brain function, and brain neurotrophic factors. Advancements in our understanding of the potential of a single session of exercise to benefit cognitive performance are important for exercise prescription and to inform chronic exercise programs designed to benefit cognition.

The association between physical activity and memory interference

Habitual physical activity has been shown to improve memory performance, yet investigations into its effects concerning memory interference remain limited. Additionally, minimal research has evaluated the association between habitual physical activity behaviors occurring in different contexts (e.g., walking, basketball, swimming) and memory. Based on these gaps in the literature, the present set of six experiments evaluated the association between contextually-different physical activity behaviors (e.g., individual physical activities, physical activities performed in social settings) and memory interference among young adult samples from America and Germany. Across six experiments, we reliably demonstrated that Germans exhibited greater memory performance than Americans. We also reliably demonstrated that contextually-different physical activities are not associated with memory performance or attenuated memory interference.

Physical Activity and Children's Episodic Memory: A Meta-Analysis

PURPOSE

The purpose of this review was to evaluate the effects of physical activity on children's free recall, cued recall, and recognition episodic memory and to explore potential moderating factors.

METHODS

The following databases were searched: PubMed, ERIC, APA Psych Info, CINHAL, SPORTDiscus, and Google Scholar. Studies were included if: (1) participants were aged 4-18 years, (2) participants were typically developed, (3) participants were randomized to groups, (4) interventions employed gross movements, (5) sedentary group was used for control, (6) memory tests were quantitative, and (7) employed acute or chronic intervention.

RESULTS

14 studies met inclusion criteria resulting in the analysis of data from 7 free recall, 7 cued recall, and 8 recognition memory tests. Physical activity was found to have a positive influence on tests free (g = 0.56), cued recall (g = 0.67), and no influence on tests of recognition (g = 0.06). While some moderator analyses were significant, the authors do not consider these results to be meaningful in application.

CONCLUSIONS

The effects of acute and chronic physical activity enhance specific aspects of long-term episodic memory. These findings suggest physical activity interventions developed for children may be expected to benefit some, but not all, types of memory processing.

Acute Effect of Simultaneous Exercise and Cognitive Tasks on Cognitive Functions in Elderly Individuals with Mild Cognitive Impairment

The increasing prevalence of age-related cognitive decline, alongside the aging global population, underscores the urgent need for innovative and effective preventative strategies. While the advantages of combining physical and cognitive exercises have been recognized as a promising approach to address these socioeconomic challenges, the acute effects of such interventions on cognitive functions remain understudied. This study aimed to investigate whether simultaneous physical and cognitive exercise has a greater beneficial impact on the cognitive functions of older adults with mild cognitive impairment (MCI) than physical exercise alone or reading activities. A total of 44 MCI patients (75% females aged between 65 and 75 years) were randomly assigned to one of three groups: aerobic exercise alone (EG group, n = 15), aerobic combined with cognitive exercises (CEG group, n = 15), or a reading task for controls (CG group, n = 14). Attention, memory, and problem solving were assessed before and after the acute intervention using the Tower of Hanoi, Digit Span, and Stroop tasks, respectively. Statistical analysis revealed that both of the experimental interventions appeared to enhance cognitive function scores (p < 0.05), except for the number of moves in the Tower of Hanoi task, where no improvement was noted. In contrast, no significant differences in any cognitive performance measures were observed following the reading session. Notably, the CEG group exhibited a more pronounced positive impact, especially on working memory. This advantage was specifically evident in the digit span tasks, where significantly greater percentage gains were found in the CEG than in the CG (p = 0.02), while no significant difference existed between the EG and CG. Simultaneous combined exercise has proven to be a more effective method than aerobic physical exercise alone for improving cognitive function. The results of this study are recommended for inclusion in clinical practice guidelines to maintain the mental health of older adults, as simultaneous exercise seems to offer a time-efficient strategy to enhance cognitive performance in adults with MCI.

Interplay of physical and recognition performance using hierarchical continuous-time dynamic modeling and a dual-task training regime in Alzheimer's patients

Training studies typically investigate the cumulative rather than the analytically challenging immediate effect of exercise on cognitive outcomes. We investigated the dynamic interplay between single-session exercise intensity and time-locked recognition speed-accuracy scores in older adults with Alzheimer's dementia (N = 17) undergoing a 24-week dual-task regime. We specified a state-of-the-art hierarchical Bayesian continuous-time dynamic model with fully connected state variables to analyze the bi-directional effects between physical and recognition scores over time. Higher physical performance was dynamically linked to improved recognition (-1.335, SD = 0.201, 95% Bayesian credible interval [BCI] [-1.725, -0.954]). The effect was short-term, lasting up to 5 days (-0.368, SD = 0.05, 95% BCI [-0.479, -0.266]). Clinical scores supported the validity of the model and observed temporal dynamics. Higher physical performance predicted improved recognition speed accuracy in a day-by-day manner, providing a proof-of-concept for the feasibility of linking exercise training and recognition in patients with Alzheimer's dementia.

Highlights

Hierarchical Bayesian continuous-time dynamic modeling approachA total of 72 repeated physical exercise (PP) and integrated recognition speed-accuracy (IRSA) measurementsPP is dynamically linked to session-to-session variability of IRSAHigher PP improved IRSA in subsequent sessions in subjects with Alzheimer's dementiaShort-term effect: lasting up to 4 days after training session.

Take a Break for Memory Sake! Effects of Short Physical Activity Breaks on Inhibitory Control, Episodic Memory, and Event-Related Potentials in Children

The pervasive sedentary lifestyle exacerbated by the COVID-19 pandemic has significantly reduced physical activity (PA) among school-age children, necessitating innovative strategies to evaluate short PA breaks that are feasible in a classroom setting. This study explored the cognitive and neurophysiological (electroencephalography; EEG) impacts of short bouts of different PA modalities on inhibitory control (flanker task) and episodic memory (word recognition task) in children. Utilizing a within-participants cross-over design, thirty-six children (n = 36; 9-12 years old) attended the lab on three separate days with each visit including either a 9 min bout of sustained moderate-intensity cycling, high-intensity interval exercise (HIIE), or seated rest. Event-related potentials (ERPs) were assessed during the flanker task (P3 component) and the word recognition task (LPC and FN400 components) to elucidate the neural mechanisms underpinning behavioral outcomes. Findings indicated no differences in flanker performance but greater episodic memory recall for HIIE compared to seated rest. Neurophysiological results revealed no differences for P3, but notably larger amplitude for LPC and FN400 postcycling, particularly over parietal electrode sites. These results underscore the potential of short PA breaks to improve cognitive and neurocognitive function in children, offering a feasible integration strategy into daily school routines without extensive time commitment.

Comparing episodic memory outcomes from walking augmented reality and stationary virtual reality encoding experiences

Episodic Memory (EM) is the neurocognitive capacity to consciously recollect personally experienced events in specific spatio-temporal contexts. Although the relevance of spatial and temporal information is widely acknowledged in the EM literature, it remains unclear whether and how EM performance and organisation is modulated by self-motion, and by motor- and visually- salient environmental features (EFs) of the encoding environment. This study examines whether and how EM is modulated by locomotion and the EFs encountered in a controlled lifelike learning route within a large-scale building. Twenty-eight healthy participants took part in a museum-tour encoding task implemented in walking Augmented Reality (AR) and stationary Virtual Reality (VR) conditions. EM performance and organisation were assessed immediately and 48-hours after trials using a Remember/Familiar recognition paradigm. Results showed a significant positive modulation effect of locomotion on distinctive EM aspects. Findings highlighted a significant performance enhancement effect of stairway-adjacent locations compared to dead-end and mid-route stimuli-presentation locations. The results of this study may serve as design criteria to facilitate neurocognitive rehabilitative interventions of EM. The underlying technological framework developed for this study represents a novel and ecologically sound method for evaluating EM processes in lifelike situations, allowing researchers a naturalistic perspective into the complex nature of EM.

Lack of effects of acute exercise intensity on mnemonic discrimination

The hippocampus is thought to support episodic memory by pattern separation, thereby supporting the ability to discriminate high similarity items. Past research evaluating whether acute exercise can improve mnemonic discrimination of high similarity items is mixed. The present experiment attempts to extend these prior mixed findings by evaluating the effects of multiple exercise intensities on hippocampal-dependent, mnemonic discrimination and memory performance. Fifty-seven young adults completed a three-condition (control, moderate-intensity, and vigorous-intensity), within-subjects crossover pretest-posttest comparison. We observed no effects of acute exercise on recognition memory or mnemonic discrimination. We discuss the implications of these null findings with the broader literature by discussing the complexity of this potential exercise-mnemonic discrimination relationship, including the unique role of exercise intensity, differences in the level of processing (e.g., conceptual vs. perceptual), and unique brain regions involved in mnemonic discrimination.

Effects of an acute bout of cycling on different domains of cognitive function

The literature suggesting acute exercise benefits cognitive function has been largely confined to single cognitive domains and measures of reliant on measures of central tendencies. Furthermore, studies suggest cognitive intra-individual variability (IIV) to reflect cognitive efficiency and provide unique insights into cognitive function, but there is limited knowledge on the effects of acute exercise on IIV. To this end, this study examined the effects of acute exercise on three different cognitive domains, executive function, implicit learning, and hippocampal-dependent memory function using behavioral performance and event-related potentials (ERPs). Furthermore, this study also sought to explore the effects of an acute bout of exercise on IIV using the RIDE algorithm to separate signals into individuals components based on latency variability. Healthy adult participants (N=20; 26.3±4.8years) completed a randomized cross-over trial with seated rest or 30min of high intensity cycling. Before and after each condition, participants completed a cognitive battery consisting of the Eriksen Flanker task, implicit statistical learning task, and a spatial reconstruction task. While exercise did not affect Flanker or spatial reconstruction performance, there were exercise related decreases in accuracy (F=5.47; P=0.040), slowed reaction time (F=5.18; P=0.036), and decreased late parietal positivity (F=4.26; P=0.046). However, upon adjusting for performance and ERP variability, there were exercise related decreases in Flanker reaction time (F=24.00; P<0.001), and reduced N2 amplitudes (F=13.03; P=0.002), and slower P3 latencies (F=3.57; P=0.065) for incongruent trials. These findings suggest that acute exercise may impact cognitive IIV as an adaptation to maintain function following exercise.

The effects of acute exercise and a nap on heart rate variability and memory in young sedentary adults

Recent evidence suggests that the autonomic nervous system can contribute to memory consolidation during sleep. Whether fluctuations in cardiac autonomic activity during sleep following physical exercise contribute to the process of memory consolidation has not been studied. We assessed the effects of a non-rapid eye movement (NREM) nap following acute exercise on cardiac autonomic regulation assessed with heart rate variability (HRV) to examine if HRV influences memory processes. Fifty-six (59% female) healthy young adults (23.14 ± 3.74 years) were randomly allocated to either the exercise plus nap (ExNap, n = 27) or nap alone (NoExNap, n = 29) groups. The ExNap group performed a 40-minute moderate-intensity cycling, while the NoExNap group was sedentary prior to learning 45 neutral pictures for a later test. Subsequently, participants underwent a 60-minute NREM nap while measuring EKG, followed by a visual recognition test. Our results indicated that heart rate did not significantly differ between the groups (p = .243), whereas vagally mediated HRV indices were lower in the ExNap group compared to the NoExNap group (p < .05). There were no significant differences in sleep variables between the groups (p > .05). Recognition accuracy was significantly higher in the ExNap group than in the NoExNap group (p = .027). In addition, the recognition accuracy of the ExNap group was negatively associated with vagally mediated HRV (p < .05). Pre-nap acute exercise appears to attenuate parasympathetic activity and to alter the relationship between memory and cardiac autonomic activity.

Mutual interference between memory encoding and motor skills: the influence of motor expertise

In cognitive-motor dual-task situations, the extent of performance decrements is influenced by the attentional requirements of each task. Well-learned motor skills should be automatized, leading to less interference. This study presents two studies combining an episodic memory encoding task with well-practiced motor tasks in athletes. Study 1 asked 40 rowers (early teenagers to middle adulthood) to row on ergometers at slow or fast speeds. In study 2, Taekwondo athletes (n = 37) of different skill levels performed a well-practiced sequence of martial arts movements. Performing the motor task during encoding led to pronounced performance reductions in memory in both studies, with costs of up to 80%. Cognitive costs were even larger when rowing with the fast compared to the slow speed in study 1. Both studies also revealed decrements in motor performances under dual-task conditions: Rowing became slower and more irregular (study 1), and the quality of the Taekwondo performance was reduced. Although higher-level athletes outperformed others in motor skills under single-task conditions, proportional dual-task costs were similar across skill levels for most domains. This indicates that even well-practiced motor tasks require cognitive resources.

The impact of physical exercise on the consolidation of fear extinction memories

Based on the mechanisms of fear extinction, exposure therapy is the most common treatment for anxiety disorders. However, extinguished fear responses can reemerge even after successful treatment. Novel interventions enhancing exposure therapy efficacy are therefore critically needed. Physical exercise improves learning and memory and was also shown to enhance extinction processes. This study tested whether physical exercise following fear extinction training improves the consolidation of extinction memories. Sixty healthy men underwent a differential fearconditioning paradigm with fear acquisition training on day 1 and fear extinction training followed by an exercise or resting control intervention on day 2. On day 3, retrieval and reinstatement were tested including two additional but perceptually similar stimuli to explore the generalization of exercise effects. Exercise significantly increased heart rate, salivary alpha amylase, and cortisol, indicating successful exercise manipulation. Contrary to our expectations, exercise did not enhance but rather impaired extinction memory retrieval on the next day, evidenced by significantly stronger differential skin conductance responses (SCRs) and pupil dilation (PD). Importantly, although conditioned fear responses were successfully acquired, they did not fully extinguish, explaining why exercise might have boosted the consolidation of the original fear memory trace instead. Additionally, stronger differential SCRs and PD toward the novel stimuli suggest that the memory enhancing effects of exercise also generalized to perceptually similar stimuli. Together, these findings indicate that physical exercise can facilitate both the long-term retrievability and generalization of extinction memories, but presumably only when extinction was successful in the first place.

Moderate-to-vigorous intensity cycling exercise immediately after visual learning enhances delayed recognition memory performance

A single bout of acute aerobic exercise has been shown to improve long-term memory, though it is unclear if exercise before learning or after learning is optimal for memory enhancement. Although some research has demonstrated that exercise before learning is ideal, investigations have consistently shown that acute arousal post-learning is a powerful memory enhancer. Therefore, the purpose of this investigation was to compare the effects of self-perceived hard cycling before or after learning on recognition memory for emotional and neutral images, and examine the relationship between central noradrenergic activity and memory performance. Seventy-two males and females (18-35 years of age) participated in this between-subjects study. Participants were randomly assigned to one of the following groups: exercise before learning, exercise after learning, and control. Participants in the exercise groups engaged in 20 min of cycling at a rating of perceived exertion (RPE) of 15 ("hard") on the Borg RPE scale before or after viewing a series of 90 pleasant, unpleasant, and neutral images (30 each). Participants in the control group engaged in no exercise before or after image viewing. At several time points throughout the experiment, saliva was collected to measure salivary alpha amylase (sAA), a marker of central noradrenergic activity. One-week later, recognition memory was assessed where participants viewed 180 images (90 new) and had to identify which images were previously viewed. Participants in the exercise after learning group had significantly higher recognition memory compared to the control group, but this was not seen with exercise before learning. sAA was not correlated with memory in any group, though it did increase during exercise. These results demonstrate that acute self-perceived hard cycling post-learning, but not pre-learning, improves recognition memory, though this was unrelated to the exercise-induced increase in central noradrenergic activity as measured in saliva.

Neurobiological effects of exercise intervention for premenstrual syndrome

Background

Up to 75%-90% of women have varying degrees of premenstrual syndrome (PMS). Exercises are recognized to be beneficial to regulate the negative emotions associated with PMS; however, the effects of exercise on sadness inhibition have not yet been investigated from the neurobiological perspective.

Purpose

This study examined the effects of a single exercise intervention on the neural mechanisms mediating sadness response inhibition at the cortical level using multichannel event-related potential (ERP) recording in women with PMS.

Methods

Participants performed Go/No-go trials while viewing of sad or neutral images before and after exercise intervention, and changes in the No-go-evoked N200 (N2) ERP component were measured by electroencephalography (EEG) at multiple cortical sites. The associations of PMS Inventory scores with N2 amplitude and latency changes were then examined using Pearson's correlation analysis.

Results

There were no significant differences in N2 latency and response error rate following exercise compared to baseline. However, women with higher PMS Inventory scores (greater symptom severity) demonstrated significantly lengthen N2 latency at the Fz electrode sites during correct sad face No-go trials after exercise (p < 0.05), which was not the case in the pre-exercise baseline. We detected no significant relationship between the PMS score and N2 amplitude, either pre- or post-exercise.

Conclusion

Women with higher PMS severity exhibited longer sad N2 latencies as well as slow down the speed of reaction to negative stimuli by exercise, suggesting that the prefrontal emotion regulation network is involved in PMS symptoms and is sensitive to the beneficial effects of exercise.

Mechanism, prevention and treatment of cognitive impairment caused by high altitude exposure

Hypobaric hypoxia (HH) characteristics induce impaired cognitive function, reduced concentration, and memory. In recent years, an increasing number of people have migrated to high-altitude areas for work and study. Headache, sleep disturbance, and cognitive impairment from HH, severely challenges the physical and mental health and affects their quality of life and work efficiency. This review summarizes the manifestations, mechanisms, and preventive and therapeutic methods of HH environment affecting cognitive function and provides theoretical references for exploring and treating high altitude-induced cognitive impairment.

Physical activity interventions in older adults with a cognitive impairment: A critical review of reviews

This critical review explores the review material on physical activity combined with cognitive stimulation interventions in older adults with cognitive impairment and/or dementia. A critical, systematic, review of the review method was used, considering four electronic databases: WEB OF SCIENCE, SCOPUS, MEDLINE, and the COCHRANE ELECTRONIC LIBRARY. The search terms "exercise," "physical activity," "cognitive impairment," "dementia," and "systematic review" were used. All available reviews were marked against predetermined inclusion and exclusion criteria. There were 32 reviews that met the inclusion criteria. A combination of various types of training and aerobic exercises were the most frequently reported interventions; meanwhile, dual task training programs (combining physical exercise with cognitive stimulation), functional training programs along with exercises combination, aerobic exercise as well as strength, stretching, or balance workouts were also reported. The evidence is compelling; exercise can improve physical health by ensuring cognitive, psychological, and behavioral benefits. Overall, exercise can improve the physical and mental health of people living with dementia: there is sufficient evidence to recommend multimodal exercise.

Mind body exercise improves cognitive function more than aerobic- and resistance exercise in healthy adults aged 55 years and older - an umbrella review

Exercise is often cited as a major factor contributing to improved cognitive functioning. As a result, the relationship between exercise and cognition has received much attention in scholarly literature. Systematic reviews and meta-analyses present varying and sometimes conflicting results about the extent to which exercise can influence cognition. The aim of this umbrella review was to summarize the effects of physical exercise on cognitive functions (global cognition, executive function, memory, attention, or processing speed) in healthy adults ≥ 55 years of age.Methods An umbrella review of systematic reviews with meta-analyses investigating the effect of exercise on cognition was performed. Databases (CINAHL, Cochrane Library, MEDLINE, PsycInfo, Scopus, and Web of Science) were searched from inception until June 2023 for reviews of randomized or non-randomised controlled trials. Full-text articles meeting the inclusion criteria were reviewed and methodological quality assessed. Overlap within included reviews was assessed using the corrected covered area method (CCA). A random effects model was used to calculate overall pooled effect size with sub-analyses for specific cognitive domains, exercise type and timing of exercise.Results Database searches identified 9227 reviews. A total of 20 met the inclusion criteria. They were based on 332 original primary studies. Overall quality of the reviews was considered moderate with most meeting 8 or more of the 16 AMSTAR 2 categories. Overall pooled effects indicated that exercise in general has a small positive effect on cognition (d = 0.22; SE = 0.04; p < 0.01). Mind-body exercise had the greatest effect with a pooled effect size of (d = 0.48; SE = 0.06; p < 0.001). Exercise had a moderate positive effect on global cognition (d = 0.43; SE = 0,11; p < 0,001) and a small positive effect on executive function, memory, attention, and processing speed. Chronic exercise was more effective than acute exercise. Variation across studies due to heterogeneity was considered very high.Conclusions Mind-body exercise has moderate positive effects on the cognitive function of people aged 55 or older. To promote healthy aging, mind-body exercise should be used over a prolonged period to complement other types of exercise. Results of this review should be used to inform the development of guidelines to promote healthy aging.Trial registration PROSPERO (CDR 42022312955).

Acute evening high-intensity interval training may attenuate the detrimental effects of sleep restriction on long-term declarative memory

Recent evidence shows that a nap and acute exercise synergistically enhanced memory. Additionally, human-based cross-sectional studies and animal experiments suggest that physical exercise may mitigate the cognitive impairments of poor sleep quality and sleep restriction, respectively. We evaluated whether acute exercise may offset sleep restriction's impairment of long-term declarative memory compared to average sleep alone. A total of 92 (82% females) healthy young adults (24.6 ± 4.2 years) were randomly allocated to one of four evening groups: sleep restriction only (S5, 5-6 h/night), average sleep only (S8, 8-9 h/night), high-intensity interval training (HIIT) before restricted sleep (HIITS5), or HIIT before average sleep (HIITS8). Groups either followed a 15-min remote HIIT video or rest period in the evening (7:00 p.m.) prior to encoding 80 face-name pairs. Participants completed an immediate retrieval task in the evening. The next morning a delayed retrieval task was given after their subjectively documented sleep opportunities. Long-term declarative memory performance was assessed with the discriminability index (d') during the recall tasks. While our results showed that the d' of S8 (0.58 ± 1.37) was not significantly different from those of HIITS5 (-0.03 ± 1.64, p = 0.176) and HIITS8 (-0.20 ± 1.28, p = 0.092), there was a difference in d' compared to S5 (-0.35 ± 1.64, p = 0.038) at the delayed retrieval. These results suggest that the acute evening HIIT partially reduced the detrimental effects of sleep restriction on long-term declarative memory.

Aerobic exercise after extinction learning reduces return of fear and enhances memory of items encoded during extinction learning

Fear conditioning paradigms are widely used in laboratory settings to discover treatments that enhance memory consolidation and various fear processes (extinction learning, limit return of fear) that are relevant targets of exposure-based therapies. However, traditional lab-based paradigms often use the exact same conditioned stimuli for acquisition and extinction (typically differentiated with a context manipulation), whereas the opposite is true in clinical settings, as exposure therapy rarely (if ever) uses precisely the exact same stimuli from an individual's learning history. Accordingly, this study utilized a novel three-day category-based fear conditioning protocol (that uses categories of non-repeating objects [animals and tools] as conditioned stimuli during fear conditioning and extinction) to determine if aerobic exercise enhances the consolidation of extinction learning (reduces return of fear) and memory (for items encoded during extinction) during subsequent tests of extinction recall. Participants (n=40) completed a fear acquisition (day 1), fear extinction (day 2), and extinction recall (day 3) protocol. On day 1, participants completed a fear acquisition task in which they were trained to associate a category of conditioned stimuli (CS+) with the occurrence of an unconditioned stimulus (US). On day 2, participants were administered a fear extinction procedure during which CS+ and CS- categorical stimuli were presented in absence of the occurrence of the US. After completing the task, participants were randomly assigned to either receive moderate-intensity aerobic exercise (EX) or a light-intensity control (CON) condition. On day 3, participants completed fear recall tests (during which day 1, day 2, and novel CS+ and CS- stimuli were presented). Fear responding was assessed via threat expectancy ratings and skin conductance responses (SCR). During the fear recall tests, the EX group reported significantly lower threat expectancy ratings to the CS+ and CS- and exhibited greater memory of CS+ and CS- stimuli that were previously presented during day 2. There were no significant group differences for SCR. These results suggests that administration of moderate-intensity aerobic exercise following extinction learning contributes to reduced threat expectancies during tests of fear recall and enhanced memory of items encoded during extinction.

The effects of physical activity timing and complexity on episodic memory: A randomized controlled trial

The role of two types of acute physical activity (PA) bouts were assessed on young adults' free-recall and recognition memory in two experiments, which differed in the temporal relation of PA and word encoding. Before or following training on the Rey Auditory Verbal Learning Task, participants performed a simple two-step dance, a complex four-step dance, or remained seated. Hypotheses proposed that PA prior to encoding and complex PA would enhance PA's mnemonic benefits. Memory assessed post-PA, 24 h, and 7 days after training indicated that timing and complexity of PA did not impact free-recall or recognition memory. Findings differ from a previous study showing complex PA benefited motor learning more than simple PA (Tomporowski & Pendleton, 2018). The inconsistency may be due to different working memory processes underlying consolidation and retrieval of procedural or episodic information. Theory-based explanations regarding memory storage and retrieval are proposed to elucidate this selective process.

Effects of acute exercise on memory: Considerations of exercise intensity, post-exercise recovery period and aerobic endurance

Accumulating research demonstrates that acute exercise can enhance long-term episodic memory. However, it is unclear if there is an intensity-specific effect of acute exercise on long-term episodic memory function and whether this is influenced by the post-exercise recovery period, which was the primary objective of this experiment. Another uncertainty in the literature is whether aerobic endurance influences the interaction between exercise intensity and post-exercise recovery period on long-term episodic memory function, which was a secondary objective of this study. With exercise intensity and post-exercise recovery period occurring as within-subject factors, and fitness as a between-subject factor, 59 participants (M_age = 20 years) completed 12 primary laboratory visits. These visits included a 20-min bout of exercise (Control, Moderate, and Vigorous), followed by a recovery period (1, 5, 10, and 15 min) and then a word-list episodic memory task, involving an encoding phase and two long-term recall assessments (20-min and 24-h delayed recall). The primary finding from this experiment was that moderate and vigorous-intensity exercise improved memory function when compared to a non-exercise control. A secondary finding was that individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, had greater memory performance after exercise (moderate or vigorous) when compared to after a control condition. Additionally, individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, generally performed better on the memory task with longer post-exercise recovery periods. Future research should carefully consider these parameters when evaluating the effects of acute exercise on long-term episodic memory.

The power of negative and positive episodic memories

The power of episodic memories is that they bring a past moment into the present, providing opportunities for us to recall details of the experiences, reframe or update the memory, and use the retrieved information to guide our decisions. In these regards, negative and positive memories can be especially powerful: Life’s highs and lows are disproportionately represented in memory, and when they are retrieved, they often impact our current mood and thoughts and influence various forms of behavior. Research rooted in neuroscience and cognitive psychology has historically focused on memory for negative emotional content. Yet the study of autobiographical memories has highlighted the importance of positive emotional memories, and more recently, cognitive neuroscience methods have begun to clarify why positive memories may show powerful relations to mental wellbeing. Here, we review the models that have been proposed to explain why emotional memories are long-lasting (durable) and likely to be retrieved (accessible), describing how in overlapping—but distinctly separable—ways, positive and negative memories can be easier to retrieve, and more likely to influence behavior. We end by identifying potential implications of this literature for broader topics related to mental wellbeing, education, and workplace environments.

Temporal endurance of exercise-induced benefits on hippocampus-dependent memory and synaptic plasticity in female mice

Exercise facilitates hippocampal neurogenesis and neuroplasticity that in turn, promotes cognitive function. Our previous studies have demonstrated that in male mice, voluntary exercise enables hippocampus-dependent learning in conditions that are normally subthreshold for long-term memory formation in sedentary animals. Such cognitive enhancement can be maintained long after exercise has ceased and can be re-engaged by a subsequent subthreshold exercise session, suggesting exercise-induced benefits are temporally dynamic. In females, the extent to which the benefits of exercise can be maintained and the mechanisms underlying this maintenance have yet to be defined. Here, we examined the exercise parameters required to initiate and maintain the benefits of exercise in female C57BL/6J mice. Using a subthreshold version of the hippocampus-dependent task called object-location memory (OLM) task, we show that 14d of voluntary exercise enables learning under subthreshold acquisition conditions in female mice. Following the initial exercise, a 7d sedentary delay results in diminished performance, which can be re-facilitated when animals receive 2d of reactivating exercise following the sedentary delay. Assessment of estrous cycle reveals enhanced wheel running activity during the estrus phase relative to the diestrus phase, whereas estrous phase on training or test had no effect on OLM performance. Utilizing the same exercise parameters, we demonstrate that 14d of exercise enhances long-term potentiation (LTP) in the CA1 region of the hippocampus, an effect that persists throughout the sedentary delay and following the reactivating exercise session. Previous studies have proposed exercise-induced BDNF upregulation as the mechanism underlying exercise-mediated benefits on synaptic plasticity and cognition. However, our assessment of hippocampal Bdnf mRNA expression following memory retrieval reveals no difference between exercise conditions and control, suggesting that persistent Bdnf upregulation may not be required for maintenance of exercise-induced benefits. Together, our data indicate that 14d of voluntary exercise can initiate long-lasting benefits on neuroplasticity and cognitive function in female mice, establishing the first evidence on the temporal endurance of exercise-induced benefits in females.

Acute effects of real and imagined endurance exercise on sustained attention performance

This study investigated acute effects of real and imagined endurance exercise on sustained attention performance in healthy young adults in order to shed light on the action mechanisms underlying changes in cognitive functioning. The neural similarities between both imagined and physically performed movements reveal that imagery induces transient hypofrontality, whereas real exercise reflects both transient hypofrontality effects and the global release of signaling factors (e.g., BDNF or serotonin) due to muscle contraction and the accompanying sensory feedback. We hypothesized improved cognitive functioning after both interventions (imagery and physical endurance exercise) with greater improvements for real exercise because it targets both mechanisms. Fifty-three sport science students completed two 25-min sessions of moderate endurance exercise in either a motor imagery modality or an executed bodily activity within the framework of an order-balanced crossover study. Assessments for sustained attention performance (d2-R) were performed before and after each endurance exercise condition. Statistical results showed improvements for both groups over time, which can mostly be explained by retest effects. However, we observed a significant interaction effect between group and time, F(1.6, 81.9) = 3.64, p = 0.04, η² = 0.07, with higher increases in the first session in case physical endurance exercise was performed compared to motor imagery exercise, t(51) = −2.71, p = 0.09, d = 0.75. This might suggest that the release of signaling factors due to muscle contractions with sensory feedback processing is an additional mediating mechanism alongside motor-related transient hypofrontality that improves cognitive performance.

Examining the Effect of Increased Aerobic Exercise in Moderately Fit Adults on Psychological State and Cognitive Function

Regular physical exercise can decrease the risk for obesity, diabetes, and cardiovascular disease, increase life expectancy, and promote psychological health and neurocognitive functioning. Cross-sectional studies show that cardiorespiratory fitness level (VO2 max) is associated with enhanced brain health, including improved mood state and heightened cognitive performance. Interventional studies are consistent with these cross-sectional studies, but most have focused on low-fit populations. Few such studies have asked if increasing levels of physical activity in moderately fit people can significantly enhance mood, motivation, and cognition. Therefore, the current study investigated the effects of increasing aerobic exercise in moderately fit individuals on psychological state and cognitive performance. We randomly assigned moderately fit healthy adults, 25-59 years of age, who were engaged in one or two aerobic exercise sessions per week to either maintain their exercise regimen (n = 41) or increase their exercise regimen (i.e., 4-7 aerobic workouts per week; n = 39) for a duration of 3 months. Both before and after the intervention, we assessed aerobic capacity using a modified cardiorespiratory fitness test, and hippocampal functioning via various neuropsychological assessments including a spatial navigation task and the Mnemonic Similarity Task as well as self-reported measures including the Positive and Negative Affect Scale, Beck Anxiety Inventory, State-Trait Anxiety Inventory, Perceived Stress Scale, Rumination Scale, Eating Disorders Examination, Eating Attitudes Test, Body Attitudes Test, and Behavioral Regulation of Exercise Questionnaire. Consistent with our initial working hypotheses, we found that increasing exercise significantly decreased measures of negative affect, including fear, sadness, guilt, and hostility, as well as improved body image. Further, we found that the total number of workouts was significantly associated with improved spatial navigation abilities and body image as well as reduced anxiety, general negative affect, fear, sadness, hostility, rumination, and disordered eating. In addition, increases in fitness levels were significantly associated with improved episodic memory and exercise motivation as well as decreased stress and disordered eating. Our findings are some of the first to indicate that in middle-aged moderately-fit adults, continuing to increase exercise levels in an already ongoing fitness regimen is associated with additional benefits for both psychological and cognitive health.

Simulating the Benefits of Nature Exposure on Cognitive Performance in Virtual Reality: A Window into Possibilities for Education and Cognitive Health

Purpose: This one-group pretest−posttest, designed within a subject study, looks to compare the effects of an outdoor nature walk (ONW) to those of a virtual nature walk (VRW) on memory and cognitive function. Implications are discussed for education as well as for the world of virtual reality. Methods: Sixty-four healthy university students were asked to complete an ONW and a VRW, which was created using 3D video of the same nature trail used for the ONW. The VRW condition involved a five-minute walk on a treadmill, while wearing a virtual reality mask (Oculus, San Francisco, USA) that projected a previously recorded three-dimensional capture of the same nature walk they experienced outdoors. Both experimental conditions lasted approximately 5 min and were counterbalanced between participants. A Digit Span Test (Digit) for working memory and a Trail Test (TMT) for executive function were administered to all study participants, immediately before and after each type of walk. Results: For executive function testing (Trail Making Test), our results demonstrate that both the ONW and VRW condition improved the TMT time, when compared to a baseline (ONW 37.06 ± 1.31 s vs. 31.75 ± 1.07 s, p < 0.01 and VRW 36.19 ± 1.18 s vs. 30.69 ± 1.11 s, p < 0.01). There was no significant difference between the ONW and VRW groups. Similarly, for the Digit memory task, both conditions improved compared to the baseline (ONW 54.30 ± 3.01 vs. 68.4 ± 2.66, p < 0.01 and VRW 58.1 ± 3.10 vs. 67.4 ± 2.72, p < 0.01). There was a difference at the baseline between the ONW and VRW conditions (54.3 ± 3.01 vs. 58.1 ± 3.10, p < 0.01), but this baseline difference in memory performance was no longer significant post exercise, between groups at follow-up (68.4 ± 2.66 vs. 67.4 ± 2.72, p < 0.08). Conclusions: Our results suggest that both a virtual reality protocol and a nature walk can have positive outcomes on memory and executive function in younger adults.

Vigorous-intensity acute exercise during encoding can reduce levels of episodic and false memory

The potential benefits (veridical memory) and, importantly, costs (false memory) of acute exercise on memory in conjunction with the timing and type of exercise have not been fully studied. In Experiment 1, we employed a three-condition (15-minute vigorous-intensity acute exercise Before or During memory encoding, or a Control condition of watching a video), within-subjects, counterbalanced design. The procedures included an immediate and delayed (20-minute post encoding) free recall assessment. Veridical memory was determined by the number of studied words that were recalled, whereas false memory was determined by retrieving a non-presented, critical item. For veridical memory, Before was not different than Control (p = .42), however, During was worse than Before and Control (p's < .001). No differences occurred for false memory. Experiment 2 was conducted that included several additional exercise conditions (e.g., light-intensity exercise) during memory encoding, used a recognition task instead of a free recall task, and extended the long-term memory assessment out to 24-hours. Experiment 2 demonstrated that vigorous-intensity acute exercise during encoding reduced both veridical and false memory for related new items (p < .05). These findings demonstrate that the timing and intensity of exercise play an important role in influencing memory performance.

Serum BDNF and Selenium Levels in Elite Athletes Exposed to Blows

Background and Objectives: The study aimed to investigate the combined acute and long-term effects of exposure to blows and exercise on serum BDNF (brain-derived neurotrophic factor) and selenium levels. Materials and Methods: Serum BDNF and selenium levels were determined in 40 male elite athletes before and after vigorous exercise (training match) with a probability of exposure to blows and in 10 sedentary men subjected to exercise (Astrand running protocol). Results: Serum BDNF levels were found 11.50 ± 3.50 ng/mL before exercise and 14.02 ± 3.15 ng/mL after exercise in the athlete group (p = 0.02), and 12.18 ± 4.55 ng/ mL and 11.74 ± 2.48 ng/ mL before and after exercise in the sedentary group, respectively (p = 0.873). Serum BDNF (pre-exercise, baseline) levels were slightly lower in the athlete group than those in the sedentary group (11.50 ± 3.50 and 12.18 ± 4.55 ng/mL, respectively, p = 0.796). Pre-exercise serum selenium levels in athletes were significantly higher compared to those of sedentary participants (130.53 ± 36.79 and 95.51 ± 20.57 µg/L, respectively, p = 0.011). There was no difference in selenium levels after exercise (124.01 ± 29.96 µg/L) compared to pre-exercise (130.53 ± 36.79 µg/L) in the athlete group (p = 0.386). Similarly, there was no difference in selenium levels after exercise (113.28 ± 25.51 µg/L) compared to pre-exercise (95.51 ± 20.57 µg/L) in the sedentary group (p = 0.251). Conclusions: BDNF results show that even if athletes are exposed to blows, they may be protected from the long-term effects of blows thanks to the protective effect of their non-sedentary lifestyle. Regular exercise may have a protective effect on maintaining serum selenium levels in athletes even exposed to blows chronically.

Can exercise shape your brain? A review of aerobic exercise effects on cognitive function and neuro-physiological underpinning mechanisms

It is widely accepted that physical exercise can be used as a tool for the prevention and treatment of various diseases or disorders. In addition, in the recent years, exercise has also been successfully used to enhance people's cognition. There is a large amount of research that has supported the benefits of physical exercise on human cognition, both in children and adults. Among these studies, some have focused on the acute or transitory effects of exercise on cognition, while others have focused on the effects of regular physical exercise. However, the relation between exercise and cognition is complex and we still have limited knowledge about the moderators and mechanisms underlying this relation. Most of human studies have focused on the behavioral aspects of exercise-effects on cognition, while animal studies have deepened in its possible neuro-physiological mechanisms. Even so, thanks to advances in neuroimaging techniques, there is a growing body of evidence that provides valuable information regarding these mechanisms in the human population. This review aims to analyze the effects of regular and acute aerobic exercise on cognition. The exercise-cognition relationship will be reviewed both from the behavioral perspective and from the neurophysiological mechanisms. The effects of exercise on animals, adult humans, and infant humans will be analyzed separately. Finally, physical exercise intervention programs aiming to increase cognitive performance in scholar and workplace environments will be reviewed.

Effects of acute exercise on emotional memory

Research has demonstrated beneficial effects of acute exercise on memory for neutral materials, such as word lists of neutral valence/low arousal. However, the impacts of exercise on emotional memory is less understood. Across three laboratory experiments in college students, we tested if acute exercise could enhance both neutral and emotional memory performance, anticipating a greater effect for emotional memory. We examined effects of exercise at varying intensities (Experiment 1: high-intensity; Experiment 2: low- and high-intensity; Experiment 3: moderate-intensity), of diverse modalities (Experiment 1: treadmill jogging; Experiment 2: cycling; Experiment 3: open-skill (racquetball) and closed-skill (treadmill jogging) exercise), and on emotional memory performance assessed at increasing levels of hippocampal dependency (Experiment 1: Y/N recognition task; Experiment 2: paired-associative recognition task; Experiment 3: cued-recall task). We found that, in all experiments, acute exercise did not significantly influence emotional or neutral memory performance relative to sedentary control conditions. However, we observed several noteworthy outcomes indicating that acute exercise may be linked to improvements in memory confidence and accuracy for central aspects of emotional memory stimuli, and that select exercise modalities (e.g. treadmill exercise) may also be associated with increased frequency of memory intrusions.

Daily Level Association of Physical Activity and Performance on Ecological Momentary Cognitive Tests in Free-living Environments: A Mobile Health Observational Study

BACKGROUND

Research suggests that physical activity (PA) has both acute and chronic beneficial effects on cognitive function in laboratory settings and under supervised conditions. Mobile health technologies make it possible to reliably measure PA and cognition in free-living environments, thus increasing generalizability and reach. Research is needed to determine whether the benefits of PA on cognitive function extend from the laboratory to real-world contexts.

OBJECTIVE

This observational study aims to examine the association between daily fluctuations in PA and cognitive performance using mobile health technologies in free-living environments.

METHODS

A total of 90 adults (mean age 59, SD 6.3 years; 65/90, 72% men) with various comorbidities (eg, cardiovascular risk and HIV) and different levels of baseline cognition (ranging from cognitively normal to impaired) completed ecological momentary cognitive tests (EMCTs) on a smartphone twice daily while wearing an accelerometer to capture PA levels for 14 days. Linear mixed-effects models examined the daily associations of PA with executive function and verbal learning EMCTs. Moderation analyses investigated whether the relationship between daily PA and daily performance on EMCTs changed as a function of baseline cognition, cardiovascular risk, and functional status (independent vs dependent).

RESULTS

Days with greater PA were associated with better (faster) performance on an executive function EMCT after covariate adjustment (estimate -0.013; β=-.16; P=.04). Moderation analyses (estimate 0.048; β=.58; P=.001) indicated that days with greater PA were associated with better (faster) executive function performance in individuals who were functionally dependent (effect size -0.53; P<.001) and not in functionally independent adults (effect size -0.01; P=.91).

CONCLUSIONS

EMCTs may be a sensitive tool for capturing daily-level PA-related fluctuations in cognitive performance in real-world contexts and could be a promising candidate for tracking cognitive performance in digital health interventions aimed at increasing PA. Further research is needed to determine individual characteristics that may moderate the association between daily PA and EMCT performance in free-living environments.

EXPRESS: Effects of Acute Exercise Intensity on Source Episodic Memory and Metamemory Accuracy

Prior research suggests that behavioral (e.g., exercise) and psychological factors (e.g., metamemory; monitoring and control of one's memory processes) may influence memory function. However, there is conflicting results on the optimal intensity of acute exercise to enhance memory and whether acute exercise can also enhance metamemory. Further, very limited research has evaluated whether acute exercise can influence source episodic memory. The objective of this study was to evaluate whether there is an intensity-specific effect of acute aerobic exercise on source episodic memory and metamemory accuracy. Thirty young adults participated in a three condition (Control/Moderate/Vigorous-Intensity Exercise), within-subject counterbalanced experimental study. After each intervention, participants completed source episodic memory and metamemory tasks. Results demonstrated that acute exercise, relative to control, was effective in enhancing source episodic memory, but not metamemory accuracy. Vigorous-intensity acute exercise was the most optimal intensity to enhance source episodic memory. Overall, our findings suggest that there is an intensity-specific effect of acute exercise on source episodic memory. Further, when exercise-related improvements in memory occur, young adults may be unaware of these memory benefits from exercise.

Enhanced recognition of emotional images is not affected by post-exposure exercise-induced arousal

Research suggests that aerobic exercise (i.e., exercise aiming to improve cardiovascular fitness) promotes cognition, but the impact on memory specifically, is unclear. There is some evidence to suggest that as little as one session of post-learning exercise benefits memory consolidation. Furthermore, memory may be particularly facilitated by exercise when the individual is emotionally aroused while encoding stimuli. The current study tested whether exercise after exposure to neutral and emotional images improved memory consolidation of the items among university students. Ninety-nine students were randomly instructed to either exercise or not exercise after viewing a set of images that were positive, neutral, and negative in valence, and they were later tested on their memory. Although emotional images were remembered better than non-emotional images, the results suggested that exercise did not influence this effect or enhance consolidation of the items overall. Explanations and implications for these findings are discussed.

Moderate intensity cycling combined with cognitive dual-task improves selective attention

Physical and cognitive exercises have positive long-term effects on cognitive capacities. However, acute effects still are controversial. Here we determine the acute effects of physical exercise combined with concurrent cognitive exercise on cognitive performance in young adults. Simple reaction time, selective attention, and memory were evaluated in 23 young men before and after 30 min of stationary cycling exercise, 30 min of stationary cycling exercise combined with cognitive exercise, and 30 min of rest. Exercise intensity was continuously controlled to ensure exercise at moderate intensity. We found that physical exercise combined with cognitive dual-task improves selective attention. Both exercise conditions showed similar effects on simple reaction time, and memory was not affected by the different exercise conditions. We conclude that the combination of cycling exercise at moderate intensity with a cognitive exercise acutely improves selective attention in young adults. These results can be of particular interest for interventions aiming at improving selective attention in sports and for older adults and individuals with difficulty to suppress and filter out task-irrelevant information, like when receiving instruction or learning a new task or concept.

Acute and Chronic Exercise Effects on Human Memory: What We Know and Where to Go from Here

Although the acquisition, storage, and retrieval of memories was once thought to happen within a single memory system with multiple processes operating on it, it is now believed that memory is comprised of both distinct and interacting brain systems [...].

Can acute resistance exercise facilitate episodic memory encoding?

Research has shown benefits of physical exercise on memory performance when carried out before or after a memory task. The effects of concurrent physical exercise and particularly resistance exercise are still inconclusive. The current study investigates the influence of resistance exercise with two intensities (fast and slow squats) on performance in a wordlist learning task using a within-subject design. Sport students (N = 58, Mage = 23 years; 26 women) were trained in a mnemonic technique to encode word lists (method of loci). In each session they were asked to encode two lists, each consisting of 20 words. During encoding, participants either performed one squat per word (fast-squat-condition), one squat every second word (slow-squat-condition), or stayed seated (control-condition). Participants performed three sessions for each condition, in counterbalanced order. Heart rates differed significantly according to exercise intensity. Memory performances in the sitting condition were better, compared to the exercise conditions. Performance in sitting and the fast squat conditions improved similarly over time, while performance in the slow squat condition increased faster, and reached the level of the fast squat condition at the end of the study phase. We conclude that light to moderate resistance exercise while working on an episodic memory task may rather represent a dual-task situation (= two tasks that compete for attentional resources). Especially doing a squat every second word may represent an inhibition task that people have to get used to. Future studies should include biochemical markers of arousal and neuronal plasticity in addition to heart rate.

Evaluation of the transient hypofrontality theory in the context of exercise: A systematic review with meta-analysis

Accumulating research suggests that, as a result of reduced neural activity in the prefrontal cortex (PFC), higher-order cognitive function may be compromised while engaging in high-intensity acute exercise, with this phenomenon referred to as the transient hypofrontality effect. However, findings in this field remain unclear and lack a thorough synthesis of the evidence. Therefore, the purpose of this meta-analysis was to evaluate the effects of in-task acute exercise on cognitive function, and further, to examine whether this effect is moderated by the specific type of cognition (i.e., PFC-dependent vs. non-PFC-dependent). Studies were identified by electronic databases in accordance with the PRISMA guidelines. In total, 22 studies met our inclusion criteria and intercept only meta-regression models with robust variance estimation were used to calculate the weighted average effect sizes across studies. Acute exercise at all intensities did not influence cognitive function (β = -0.16, 95% CI = [-0.58, 0.27], p = .45) when exercise occurred during the cognitive task, and no significant moderation effects emerged. However, there was evidence that cognitive task type (PFC-dependent vs. non-PFC-dependent) moderated the effect of high-intensity acute exercise on a concomitant cognitive performance (β = -0.81, 95% CI = [-1.60, -0.02], p = .04). Specifically, our findings suggest that PFC-dependent cognition is impaired while engaging in an acute bout of high-intensity exercise, providing support for the transient hypofrontality theory. We discuss these findings in the context of reticular-activating and cognitive-energetic perspectives.

Brain Activity-Based Metrics for Assessing Learning States in VR under Stress among Firefighters: An Explorative Machine Learning Approach in Neuroergonomics

The nature of firefighters` duties requires them to work for long periods under unfavorable conditions. To perform their jobs effectively, they are required to endure long hours of extensive, stressful training. Creating such training environments is very expensive and it is difficult to guarantee trainees' safety. In this study, firefighters are trained in a virtual environment that includes virtual perturbations such as fires, alarms, and smoke. The objective of this paper is to use machine learning methods to discern encoding and retrieval states in firefighters during a visuospatial episodic memory task and explore which regions of the brain provide suitable signals to solve this classification problem. Our results show that the Random Forest algorithm could be used to distinguish between information encoding and retrieval using features extracted from fNIRS data. Our algorithm achieved an F-1 score of 0.844 and an accuracy of 79.10% if the training and testing data are obtained at similar environmental conditions. However, the algorithm's performance dropped to an F-1 score of 0.723 and accuracy of 60.61% when evaluated on data collected under different environmental conditions than the training data. We also found that if the training and evaluation data were recorded under the same environmental conditions, the RPM, LDLPFC, RDLPFC were the most relevant brain regions under non-stressful, stressful, and a mix of stressful and non-stressful conditions, respectively.

Swimming exercise improves short- and long-term memories: Time-course changes

The beneficial effects of exercise training on memory formation are well documented. However, the memory enhancement profile following the time-course of exercise training remains unknown. In this investigation, changes in the spatial hippocampal memory following a time-course of swimming exercise training were examined. Young adult Wistar rats were tested for both short-term and long-term memories using the radial arm water maize (RAWM) paradigm following 0, 1, 7, 14, and 28 days of swimming exercise training (60 min per day, 5 days/week)s. The mean total errors on RAWM during the learning phase and memory testing remained the same (p > 0.5) after 1 day of swimming exercise. On the other hand, swimming exercise-induced significant enhancement to the learning phase and memory formation after 7 days of training (p < 0.01). Errors decreased (p < 0.0001) after 7 days of training and remained lower (p < 0.0001) than baseline without differences between 7, 14, and 28 days (p > 0.5). Similarly, short- and long-term memories improved after 7 days (p < 0.05) of training as compared to the baseline without differences between 7, 14, and 28 days (p > 0.05). The time course of improvement of learning and both short- and long-term memories after swimming exercise were evident after 7 days and plateaued thereafter. Results of the current study could form the base for future utilization of exercises to enhance cognitive function in healthy individuals.

Movement-based mind-body practices and cognitive function in middle-aged and older adults: Findings from the Midlife in the United States (MIDUS) study

OBJECTIVES

Cognitive function is a key component of healthy aging. While conventional physical activities (walking, jogging, etc.) have been shown to support physical and cognitive health in late-life, it remains unclear whether traditional Eastern movement-based mind-body practices (MBP) have long-term cognitive benefits above and beyond conventional leisure physical activities. This study examines the relationship between movement-based MBP and cognitive function in middle-aged and older adults during a 10-year follow-up period.

METHODS

We used data from Waves 2 (2004-05) and 3 (2013-14) of the Midlife in the United States (MIDUS) study. MIDUS initially surveyed a national probability sample of community-living adults aged 24-75 years in 1995 (Wave 1). Tests of cognitive functioning measuring executive function and episodic memory were added in Wave 2 and repeated in Wave 3. We estimated multivariable linear regression models to examine the effect of MBP (Wave 2) on the episodic memory and executive function (Wave 3) while controlling for covariates (sociodemographic factors, health, and cognitive function at Wave 2).

RESULTS

A total of 2097 individuals aged 42-92 years (M = 64 ± 11, 56 % women) were included. After controlling for sociodemographic factors, health and functional status, and prior levels of cognitive function, engaging in MBP was independently associated with a smaller decline in episodic memory (b = 0.11, p = .03), but not executive function (b=0.03, p = .34).

DISCUSSION

The findings provide the first large population-based evidence supporting the cognitive benefits of MBP over a 10-year period among middle-aged and older adults. Future research should examine whether MBP are effective non-pharmacological intervention to attenuate age-related cognitive decline.

Examining the Role of Physical Activity on Word Learning in School-Aged Children

Purpose Previous studies show that there is increased brain activity after exercise, leading to improved word recall in adults. The aim of this study was to examine whether different types of exercise (i.e., aerobic vs. anaerobic) may also lead to improved performance during vocabulary learning in children. Method A total of 48 participants (24 in Experiment 1 and 24 in Experiment 2) between the ages of 6 and 12 years completed a word learning task. Training of words took place in a resting and in an exercise condition using a within-subject design. In the resting measure, children were taught names of novel objects and then colored for 3 min before being tested on their ability to recognize the words. In the exercise condition, the same steps were followed, but instead of coloring, children engaged in 3 min of either aerobic exercise (i.e., swimming in Experiment 1) or anaerobic exercise (i.e., a CrossFit-like workout in Experiment 2). Results In Experiment 1, accuracy of word recognition was significantly higher for words that were trained in the aerobic exercise compared to the resting condition. In Experiment 2, there was no significant difference in performance between the anaerobic exercise and resting conditions. Conclusions These findings suggest that previously identified benefits of exercise on language abilities in adults also extend to school-aged children. However, not all types of physical activity lead to this boost in performance, as only aerobic (but not anaerobic) exercise improved children's ability to acquire new word-object relations. Supplemental Material https://doi.org/10.23641/asha.14462187.

Effect of regular resistance training on memory in older adults: A systematic review

The purpose of this study was to evaluate the effect of regular resistance training on memory in older adults.

METHODS

Eight databases (PubMed, Cochrane Library, EMBASE, Web of Science, SinoMed, China National Knowledge Infrastructure (CNKI), China Science and Technology Periodical Database (VIP) and Wanfang) were searched from their inception to March 24, 2021. The data included in the study were analysed according to the Cochrane handbook using Review Manager 5.3 software.

RESULTS

Eighteen eligible randomized controlled trials (RCTs) with a total of 1365 older adults were identified that met the inclusion criteria for the systematic review. Compared with no specific exercise or a low intensity exercise control, regular resistance training significantly improved working memory (standardized mean difference (SMD): 0.27, 95% confidence interval (CI): 0.11, 0.42, P < 0.001), immediate memory (SMD: 0.27, 95% CI: 0.01, 0.54, P = 0.04), and short-term memory (SMD: 0.68, 95% CI: 0.23,1.14, P = 0.003) but had no significant impact on verbal memory (SMD: 0.15, 95% CI: -0.40, 0.71, P = 0.59) or delayed memory (SMD: 0.01, 95% CI: -0.39, 0.42, P = 0.18).

CONCLUSIONS

Regular resistance training has a positive beneficial effect on working memory, immediate memory and short-term memory in older adults. However, due to the limitations of the included studies, these findings should be interpreted cautiously.

Acute exercise and cognition: A review with testable questions for future research into cognitive enhancement with blood flow restriction

Blood flow restriction, in combination with low load/intensity exercise, has consistently been shown to increase both muscle size and strength. In contrast, the effects of blood flow restricted exercise on cognition have not been well studied. Therefore, the purpose of this paper is 1) to review the currently available literature investigating the impact of blood flow restricted exercise on cognition and 2) to provide some hypotheses for how blood flow restriction might provide an additive stimulus for augmenting specific cognitive domains above exercise alone. Given the lack of research in this area, the effects of blood flow restricted exercise on cognition are still unclear. We hypothesize that blood flow restricted exercise could potentially enhance several cognitive domains (such as attention, executive functioning, and memory) through increases in lactate production, catecholamine concentration, and PGC-1α expression. We review work that suggests that blood flow restriction is not only a beneficial strategy to improve musculoskeletal function but could also be a favorable method for enhancing multiple domains of cognition. Nonetheless, it must be emphasized this is a hypothesis that currently has only minimal experimental support, and further investigations in the future are necessary to test the hypothesis.

The Effect of Acute High-Intensity Interval Training on Executive Function: A Systematic Review

Acute high-intensity interval training (HIIT) is a time-efficient strategy to improve physical health; however, the effect of acute HIIT on executive function (EF) is unclear. The aim of this study was to systematically review the existing evidence and quantify the effect of acute HIIT on overall EF and the factors affecting the relationship between acute HIIT and EF. Standard databases (i.e., the PubMed, Medline, Scopus, and CENTRAL databases) were searched for studies that examined the effect of acute HIIT on EF and were published up until January 2021. The overall EF and factors grouped by three categories, namely, EF assessment characteristics, exercise intervention characteristics, and sample and study characteristics, were analyzed by percentage of comparison for positive or null/negative effects. Overall, 35 of 57 outcomes (61%) across 24 studies revealed that acute HIIT has a positive effect on overall EF. In terms of factors, the results indicated that among EF assessment characteristics, groups, inhibition, updating, and the assessment occurring within 30 min may moderate the effect of acute HIIT on EF, while among exercise intervention characteristics, total time within 11 to 30 min may moderate the effect. Finally, among sample characteristics, age under 40 years may moderate the effect. Acute HIIT is generally considered a viable alternative for eliciting EF gains, with factors related to EF components, timing of the assessment, exercise total time, and age potentially moderating the effect of HIIT on EF.