Muscle tension induced after learning enhances long-term narrative and visual memory in healthy older adults

Effect of isometric handgrip exercise on cognitive function: Current evidence, methodology, and safety considerations

Cognitive function is essential for most behaviors of daily living and is a critical component in assessing the quality of life. Mounting prospective evidence supports the use of isometric handgrip exercise (IHE) as a small muscle mass practice to promote health-related outcomes in clinical and healthy populations. The aim of the present review was to systematically investigate whether IHE is effective in improving the cognitive function of adults (aged ≥18 years). Studies were identified by searching five databases (CINAHL, MEDLINE, SPORTDiscus, PsychINFO, and Web of Science). Eight out of 767 studies met the inclusion criteria, including three types of studies: 1) acute effect for IHE with various intensity protocols (n = 4); 2) acute effect for IHE with one set exhaustion protocol (n = 2); and 3) chronic effect of IHE on cognitive function (n = 2). To assess the methodological quality of studies, the PEDro scale was used (mean score = 6.75). The evidence on whether IHE exerts acute positive effects on cognitive performance is currently rather inconclusive. However, a trend was discernible that implementing IHE can generate a beneficial chronic effect on cognitive function, although the results should be interpreted with caution. The clinical relevance of IHE as a time-efficient type of physical exercise to improve cognitive function warrants further investigation. Methodology and safety considerations were discussed.

Systematic Review Registration: (https://osf.io/gbzp9).

The effects of acute exercise on memory of cognitively healthy seniors: A systematic review

OBJECTIVE

To systematically review the acute effects of physical exercise on memory in healthy elderly people.

METHODS

The present study consists of a systematic review based on the criteria of the Preferred Reporting Items for Systematic Reviews and Meta - Analyzes (PRISMA). Searches were carried out in the health databases: PubMed (Medline); ScienceDirect (Elsevier); SciELO, Cochrane and LILACS, including articles published until April 2021. The included studies should be randomized clinical trials in healthy elderly populations, have acute physical exercise as an intervention compared to another type of exercise or to a control session, and assess memory as an outcome.

RESULTS

A total of 3711 records were found in the databases. After reading titles and abstracts, 27 full texts of studies were selected. A total of 10 records met the inclusion criteria and were considered eligible for qualitative analysis. The total sample consisted of 465 healthy individuals, of both sexes, aged between 60 and 95 years. The aerobic and resistance exercises performed at low (7-11 Borg scale, 54% FCM or 40-54% 1RM) and moderate intensities (12-15 Borg scale, 50-70% FCM and 55-75% 1RM) lead to memory improvement in cognitively healthy elderly people.

CONCLUSIONS

The paucity of studies with this population, using higher exercise intensities, as well as a reduced variety of memory tests, were limiting factors. Maintaining a training routine is important, in order to preserve physical and mental health. More studies addressing the effects of exercise protocols in healthy individuals are warranted.

Does the combination of physical activity and attention training affect the motor skills and cognitive activities of individuals with mild intellectual disability?

Individuals with mild intellectual disability (MID) were worse than their peers who typically develop in motor skills and attention-demanding assignments. In this study, effect of a 14-week physical activity and attention training practise on the motor skills, visual retention, perception and attention levels of students with MID were analysed. Twenty-two individuals between 7 and 14 ages participated voluntarily. Activities based on developing attention skills and physical activities enhancing fine-gross motor skills (40 + 60 min./2 days/14 weeks) were given to the experimental group. d2 Test of Attention, Benton Visual Retention and Bruininks-Oseretsky Test of Motor Proficiency-2nd version tests were used as data collection tools. There was significant difference in terms of total number of items processed, commissions, raw score of errors, total number of items minus error scores, concentration performance, Benton visual retention test and perception, fine motor skill precision, fine motor skill integration, manual dexterity and upper-limb coordination values regarding group and time dependant (p< .05). However, there was no significant difference in omissions and fluctuation rate values (p> .05). As a result; it is determined that the combination of physical activity and attention training practises features a positive effect on visual retention, perception, attention and motor skill levels of students with MID.

Time-dependent effects of discrete post-encoding emotions on item memory and source memory

This study examined time-dependent effects of discrete emotions on item and source memory. In Experiment 1, after encoding, participants watched a comic, disgust-inducing, anger-inducing or neutral video at different delays. Positive emotion did not affect item memory but enhanced source memory (only in the 5 min delay). Anger impaired recognition in all delays, but a trend occurred for anger to impair source memory only in the 50 min delay. Disgust did not affect item memory, but a trend emerged for it to enhance and impair source memory in the 5 and 35 min delays, respectively. Experiment 2 showed that positive emotion and disgust had no effect on recognition, and consistent with Experiment 1, positive emotion, not anger or disgust, enhanced source memory. A trend occurred for positive emotion and disgust to impair source memory in the 0 min delay but not in the other delays. Consistent with Experiment 1, Experiment 3 showed that anger impaired both recognition and source memory (for males). Taken together, these findings suggest that the effect of emotion does vary depending on nature of memory tasks, category of emotion, and delay in emotion elicitation.

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

Background: Accumulating research demonstrates that the timing of exercise plays an important role in influencing episodic memory. However, we have a limited understanding as to the factors that moderate this temporal effect. Thus, the purpose of this systematic review with meta-analysis was to evaluate the effects of study characteristics (e.g., exercise modality, intensity and duration of acute exercise) and participant attributes (e.g., age, sex) across each of the temporal periods of acute exercise on episodic memory (i.e., acute exercise occurring before memory encoding, and during memory encoding, early consolidation, and late consolidation). Methods: The following databases were used for our computerized searches: Embase/PubMed, Web of Science, Google Scholar, Sports Discus and PsychInfo. Studies were included if they: (1) Employed an experimental design with a comparison to a control group/visit, (2) included human participants, (3) evaluated exercise as the independent variable, (4) employed an acute bout of exercise (defined as a single bout of exercise), (5) evaluated episodic memory as the outcome variable (defined as the retrospective recall of information either in a spatial or temporal manner), and (6) provided sufficient data (e.g., mean, SD, and sample size) for a pooled effect size estimate. Results: In total, 25 articles met our inclusionary criteria and were meta-analyzed. Acute exercise occurring before memory encoding (d = 0.11, 95% CI: −0.01, 0.23, p = 0.08), during early memory consolidation (d = 0.47, 95% CI: 0.28, 0.67; p < 0.001) and during late memory consolidation (d = 1.05, 95% CI: 0.32, 1.78; p = 0.005) enhanced episodic memory function. Conversely, acute exercise occurring during memory encoding had a negative effect on episodic memory (d = −0.12, 95% CI: −0.22, −0.02; p = 0.02). Various study designs and participant characteristics moderated the temporal effects of acute exercise on episodic memory function. For example, vigorous-intensity acute exercise, and acute exercise among young adults, had greater effects when the acute bout of exercise occurred before memory encoding or during the early memory consolidation period. Conclusions: The timing of acute exercise plays an important role in the exercise-memory interaction. Various exercise- and participant-related characteristics moderate this temporal relationship.

Posttraining Epinephrine Reverses Memory Deficits Produced by Traumatic Brain Injury in Rats

The aim of this research is to evaluate whether posttraining systemic epinephrine is able to improve object recognition memory in rats with memory deficits produced by traumatic brain injury. Forty-nine two-month-old naïve male Wistar rats were submitted to surgical procedures to induce traumatic brain injury (TBI) or were sham-operated. Rats were trained in an object recognition task and, immediately after training, received an intraperitoneal injection of distilled water (Sham-Veh and TBI-Veh group) or 0.01 mg/kg epinephrine (TBI-Epi group) or no injection (TBI-0 and Sham-0 groups). Retention was tested 3 h and 24 h after acquisition. The results showed that brain injury produced severe memory deficits and that posttraining administration of epinephrine was able to reverse them. Systemic administration of distilled water also had an enhancing effect, but of a lower magnitude. These data indicate that posttraining epinephrine and, to a lesser extent, vehicle injection reduce memory deficits associated with TBI, probably through induction of a low-to-moderate emotional arousal.

Timing matters: negative emotion elicited 5 min but not 30 min or 45 min after learning enhances consolidation of internal-monitoring source memory

Two experiments examined the time-dependent effects of negative emotion on consolidation of item and internal-monitoring source memory. In Experiment 1, participants (n=121) learned a list of words. They were asked to read aloud half of the words and to think about the remaining half. They were instructed to memorize each word and its associative cognitive operation ("reading" versus "thinking"). Immediately following learning they conducted free recall and then watched a 3-min either neutral or negative video clip when 5 min, 30 min or 45 min had elapsed after learning. Twenty-four hours later they returned to take surprise tests for item and source memory. Experiment 2 was similar to Experiment 1 except that participants, without conducting an immediate test of free recall, took tests of source memory for all encoded words both immediately and 24 h after learning. Experiment 1 showed that negative emotion enhanced consolidation of item memory (as measured by retention ratio of free recall) regardless of delay of emotion elicitation and that negative emotion enhanced consolidation of source memory when it was elicited at a 5 min delay but reduced consolidation of source memory when it was elicited at a 30 min delay; when elicited at a 45 min delay, negative emotion had little effect. Furthermore, Experiment 2 replicated the enhancement effect on source memory in the 5 min delay even when participants were tested on all the encoded words. The current study partially replicated prior studies on item memory and extends the literature by providing evidence for a time-dependent effect of negative emotion on consolidation of source memory based on internal monitoring.

Negative emotion elicited in high school students enhances consolidation of item memory, but not source memory

The study examined the effect of negative emotion on consolidation of both item and source memory. Participants learned words read by either a male or female. Then they watched either a negative or a neutral video clip. Memory tests were carried out either 25min or 24h after learning. The study yielded the following findings. First, negative emotion enhanced consolidation of item memory as measured by recognition memory in the 25-min delay, and enhanced consolidation of item memory as measured by free recall in both the 25-min and the 24-h delay. Second, negative emotion had little effect on consolidation of source memory, either in the 25-min or the 24-h delay. These findings provide evidence for the differential effects of negative emotion on item memory and source memory and have implications for using emotion as a strategy to intervene memory consolidation.

Sleep, cognition, and normal aging: integrating a half century of multidisciplinary research

Sleep is implicated in cognitive functioning in young adults. With increasing age, there are substantial changes to sleep quantity and quality, including changes to slow-wave sleep, spindle density, and sleep continuity/fragmentation. A provocative question for the field of cognitive aging is whether such changes in sleep physiology affect cognition (e.g., memory consolidation). We review nearly a half century of research across seven diverse correlational and experimental domains that historically have had little crosstalk. Broadly speaking, sleep and cognitive functions are often related in advancing age, though the prevalence of null effects in healthy older adults (including correlations in the unexpected, negative direction) indicates that age may be an effect modifier of these associations. We interpret the literature as suggesting that maintaining good sleep quality, at least in young adulthood and middle age, promotes better cognitive functioning and serves to protect against age-related cognitive declines.