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Voluntary aerobic exercise increases the cognitive enhancing effects of working memory training
... Laboratory animal studies have shown that combining PA with cognitive training induces larger effects on neurocognitive functioning than PA interventions alone [11][12][13]. Two systematic reviews [14,15] and two meta-analyses [16,17] suggest that this might also be the case in humans and that combined physical and cognitive training (PA + CA) strategies could be used as a modality to improve cognition in older adults. Yet, many research questions remain. ...
... Furthermore, it has been suggested that additional cognitively demanding conditions are necessary to promote synaptic plasticity and the survival and functional integration of the newly formed neurons into neural networks [70,71]. In rodents, combining PA (e.g., voluntary wheel-running) with challenging cognitive tasks (e.g., maze training) showed larger and longer-lasting gains in learning and memory abilities relative to single activity interventions [12,13]. A previous meta-analysis on healthy older adults [16] reported similarly small but significant positive effects for combined PA + CA interventions compared to PA interventions alone. ...
Abstract Background Aging-related cognitive decline and cognitive impairment greatly impacts older adults’ daily life. The worldwide ageing of the population and associated wave of dementia urgently calls for prevention strategies to reduce the risk of cognitive decline. Physical activity (PA) is known to improve cognitive function at older age through processes of neuroplasticity. Yet, emerging studies suggest that larger cognitive gains may be induced when PA interventions are combined with cognitive activity (CA). This meta-analysis evaluates these potential synergistic effects by comparing cognitive effects following combined PA + CA interventions to PA interventions (PA only), CA interventions (CA only) and control groups. Methods Pubmed, Embase, PsycInfo, CINAHL and Sportdiscus were searched for English peer-reviewed papers until April 2018. Data were extracted on cognition and factors potentially influencing the cognitive effects: mode of PA + CA combination (sequential or simultaneous), session frequency and duration, intervention length and study quality. Differences between older adults with and without mild cognitive impairments were also explored. Results Forty-one studies were included. Relative to the control group, combined PA + CA intervention showed significantly larger gains in cognition (g = 0.316; 95% CI 0.188–0.443; p
... Perhaps in order to maintain positive effects in specific areas such as learning, one has to continue exercising. Alternately, a study in mice suggests that lasting changes may result from the combination of physical exercise and cognitive training (Smith et al., 2013). Both hypotheses need to be further assessed in human trials with follow-up evaluations months to years later. ...
... Thirdly, indirect evidence suggests a benefit of adding cognitive training to a physical exercise regimen. Animal research has shown that the combination of both forms of training exceeds the benefits of either treatment alone (Langdon & Corbett, 2012), possibly with long-term effects on cognition (Smith et al., 2013). Also, a recent meta-analysis showed that this combination can be beneficial for both healthy subjects and people with cognitive impairments (Law, Barnett, Yau, & Gray, 2014). ...
Objective:
To determine whether physical exercise enhances cognition following TBI or stroke.
Data sources:
Studies were identified through searches of PubMed, ScienceDirect and the reference lists of papers that were included for full-text evaluation. Medical subject headings from three concepts, i.e. brain injury, physical exercise and cognition, were used to incorporate related search terms.
Study selection:
Included were all trials published in English that assessed cognition before and after an exercise intervention in human adults with TBI or stroke. Nine randomized and two non-randomized controlled trials, as well as three single group pre-post studies were included.
Data extraction:
Relevant data concerning the methods and results of the included studies were extracted. Methodological quality of the RCT's was evaluated using the PEDro scale. Non-randomized trials were assessed using the Downs and Black checklist.
Data synthesis:
The included trials were generally of medium methodological quality, though often plagued with issues of internal and external validity. The studies exhibited great heterogeneity, rendering a meta-analysis infeasible.
Conclusions:
Though well-designed studies are still needed, the preponderance of evidence suggests a positive effect of physical exercise on global cognitive functioning, especially in the chronic stages of a brain injury. Time after injury as well as the duration and intensity of the exercise program are mediating factors.
... Our findings indicate a significant downregulation in the expression of PSD95 and SYN in the hippocampus of mice with diet-induced insulin resistance. Extensive literature supports the beneficial effects of exercise on insulin resistance [32][33][34], hippocampal neuronal synaptic plasticity [35], and cognitive impairments [36][37][38]. Although there is substantial evidence for the positive effects of aerobic exercise on cognitive functions [39][40][41], research on the impacts of resistance training on cognitive functions is less prevalent. ...
Background
This investigation delineates the influence of resistance training on the expression of synaptic plasticity-related proteins in the hippocampi of insulin-resistant mice and explores the underlying molecular mechanisms.
Methods
Six-week-old male C57BL/6 J mice were stratified into a control group and a high-fat diet group to induce insulin resistance over a 12-week period. Subsequently, the mice were further divided into sedentary and resistance training cohorts, with the latter engaging in a 12-week ladder-climbing regimen. Post-intervention, blood, and hippocampal specimens were harvested for analytical evaluation.
Results
In the insulin-resistant mice, elevated blood lactate levels were observed alongside diminished expression of synaptic plasticity-related proteins, monocarboxylate transporters (MCTs), and reduced phosphorylation of protein kinase B (Akt) and mechanistic target of rapamycin (mTOR). In contrast, the expression of eukaryotic translation initiation factor 4 E-binding protein 2 was significantly augmented. Resistance training mitigated insulin resistance, decreased blood lactate levels, and enhanced the expression and phosphorylation of mTOR, regulatory-associated protein of mTOR, MCTs, and synaptic plasticity-related proteins.
Conclusions
Resistance training mitigates insulin resistance and improves hippocampal synaptic plasticity by normalizing blood lactate levels and enhancing mTOR, MCTs, and synaptic plasticity-related proteins. It may also activate mTORC1 via the PI3K/Akt pathway, promote lactate utilization, and enhance synaptic plasticity proteins, potentially alleviating peripheral insulin resistance. Further research is needed to confirm these mechanisms.
... In this study, the exercise intervention period was designed for 6 weeks by modeling studies verifying the effects of an aerobic exercise intervention such as running, which have been conducted in previous research. Specifically, various exercise intervention studies related to physical, cognitive, and emotional changes through aerobic exercises such as jogging have been conducted for approximately 6 to 8 weeks [18][19][20]. The exercise intervention period was designed based on these models. ...
People in situations where physical activity is difficult face limitations in participating in exercise to maintain health. Participation in exercise is especially difficult when social non-face-to-face situations such as infectious diseases occur. This causes various social problems. Background: The study developed a 3D virtual reality (VR) Motionless Imagery Exercise through Avatar (MIEA), provided customized content such as companion avatars, and aimed to verify its effects. Methods: This study was conducted using a randomized block design experiment. The participants were 40 healthy adults (20 experiment and 20 control group) aged between 19 and 49 years. Both groups engaged in interventions three times per week for 20 min over six weeks. Data obtained from measurements of emotional well-being, cognition, and physiological responses before and after the experiment were analyzed. Results: The experimental group showed significant improvements in emotional well-being compared to the control group, particularly in trait anxiety, resilience, stress, and positive affect. The similar physiological responses observed in the experimental group resembled exercise-induced responses. Verbal memory and working memory in the experimental group improved more in the experimental group than the control group. Conclusions: The results showed the effectiveness of a 3D VR MIEA, indicating its positive impact on exercise outcomes. Furthermore, the provision of customized content including companion avatars was validated to enhance emotional well-being. This suggests that incorporating content-driven companion avatars in developing virtual reality exercise programs can evoke emotional effects.
... This is at least what suggests a study [47] who showed in mices that exercise combined with a sequence of enriched environment yielded an approximately 30% greater increase in new neurons than either stimulus alone. On their side, Smith and colleagues [48] reported that exercise combined with cognitive training resulted in a greater cognitive improvement in mices than either stimulus alone, thus suggesting that adaptations reported by Fabel et al. [47] may have functional consequences on these animals. Results are more equivocal in humans, since recent narrative reviews [49][50][51], systematic reviews [52][53][54], and meta-analyses [55][56][57][58][59] have reported conflicting results. ...
Aging is characterized by cognitive decline affecting daily functioning. To manage this socio-economic challenge, several non-pharmacolog- ical methods such as physical, cognitive, and com- bined training are proposed. Although there is an important interest in this subject, the literature is still heterogeneous. The superiority of simultaneous train- ing compared to passive control and physical train- ing alone seems clear but very few studies compared simultaneous training to cognitive training alone. The aim of this pilot study was to investigate the effect of simultaneous exercise and cognitive training on several cognitive domains in healthy older adults, in comparison with either training alone. Thirty-five healthy older adults were randomized into one of three experimental groups: exercise training, cogni- tive training, and simultaneous exercise and cognitive training. The protocol involved two 30-min sessions per week for 24 weeks. Cognitive performance in several domains, pre-frontal cortex oxygenation, and baroreflex sensitivity were assessed before and after the intervention. All groups improved executive per- formance, including flexibility or working memory. We found a group by time interaction for inhibition cost (F(2,28) = 6.44; p < 0.01) and baroreflex sensitivity during controlled breathing (F(2,25)=4.22; p=0.01), the magnitude of improvement of each variable being associated (r=-0.39; p=0.03). We also found a decrease in left and right pre-frontal cortex oxygena- tion in all groups during the trail making test B. A simultaneous exercise and cognitive training are more efficient than either training alone to improve execu- tive function and baroreflex sensitivity. The results of this study may have important clinical repercussions by allowing to optimize the interventions designed to maintain the physical and cognitive health of older adults.
... 8 Recent research showed that PA interventions in school demonstrated benefits in executive functions, 9 and elevates cognitive performance. 10 Furthermore, it is suggested to have a positive impact on academic-related outcomes 11 and even increases adolescents' enjoyment of PA. 12 But lack of infrastructure and resources often remain a barrier for the implementation of PA interventions in schools. 13 Tight class schedules often do not allow additional physical education lessons. ...
... In addition, multiple interactions between different enhancers exist, which further complicates the situation. Interactions have been reported, e.g., for glucose and caffeine, 209 diet and exercise, 210 exercise and working memory training, 211 video games and sleep, 212 video games and brain stimulation, 213 exercise and brain stimulation, 214 and brain stimulation and sleep. 215,216 Also different dimensions discussed here can interact in multiple ways, as, e.g., computerized cognitive training can differentially enhance different cognitive processes depending on personal factors such as age; 217 and social acceptance of different enhancement strategies depends on both the baseline performance of users and the cognitive domain targeted. ...
In an increasingly complex information society, demands for cognitive functioning are growing steadily. In recent years, numerous strategies to augment brain function have been proposed. Evidence for their efficacy (or lack thereof) and side effects has prompted discussions about ethical, societal and medical implications. In the public debate, cognitive enhancement is often seen as a monolithic phenomenon. On a closer look, however, cognitive enhancement turns out to be a multifaceted concept: There is not one cognitive enhancer that augments brain function per se, but a great variety of interventions that can be clustered into biochemical, physical and behavioral enhancement strategies. These cognitive enhancers differ in their mode of action, the cognitive domain they target, the timescale they work on, their availability and side effects, and how they differentially affect different groups of subjects. Here we disentangle the dimensions of cognitive enhancement, review prominent examples of cognitive enhancers that differ across these dimensions, and thereby provide a framework for both theoretical discussions and empirical research.
... Practically, several studies have found that combining exercise interventions with cognitive training produces significant benefits compared to exercise or cognitive training alone (e.g. Barnes et al. 2013;Smith et al. 2013). In regions of the brain where neurogenesis is not known to occur, activation of task-dependent regions from cognitive training in other domains and consequent increased metabolic demand could result in proportionally greater oxygenation and neurotrophin delivery to those regions, enhancing plasticity. ...
... Indeed, an animal study reported that exercise and enriched environment combined in sequence led to more new neurons than exercise or enriched environment alone (Fabel et al., 2009). Combined cognitive and exercise training also produced greater cognitive improvements than either single training in mice (Langdon and Corbett, 2012;Smith et al., 2013). Law et al. (2014) systematically reviewed eight studies of combined cognitive and physical intervention in older adults. ...
Both cognitive intervention and physical exercise benefit cognitive function in older adults. It has been suggested that combined cognitive and physical intervention may induce larger effects than cognitive or physical intervention alone, but existing literature has shown mixed results. This meta-analysis aimed at assessing the efficacy of combined intervention on cognition by comparing combined intervention to control group, cognitive intervention and physical exercise. Eligible studies were controlled trials examining the effects of combined intervention on cognition in older adults without known cognitive impairment. Twenty interventional studies comprising 2667 participants were included. Results showed that the overall effect size for combined intervention versus control group was 0.29 (random effects model, p=0.001). Compared to physical exercise, combined intervention produced greater effects on overall effect size (0.22, p<0.01), while no significant difference was found between combined intervention and cognitive intervention. Effects of combined intervention were moderated by age of participants, intervention frequency and setting. The findings suggest that combined intervention demonstrates advantages over control group and physical exercise, while evidence is still lacking for superiority when compared combined intervention to cognitive intervention. More well-designed studies with long follow-ups are needed to clarify the potential unique efficacy of combined intervention for older adults.
... Working memory historically is thought to be a trait (Baddeley, 2003) with a strong genetic component (Friedman et al., 2008). Contemporary findings suggest that working memory can be improved to a degree and suggest that the underlying neural circuity has some plasticity in response to interventions such as intense cognitive training or exercise training (Jaeggi, Buschkuehl, Jonides, & Shah, 2011;Mahncke et al., 2006;McNab et al., 2009;Nagamatsu et al., 2013;Sprenger et al., 2013;Volkers & Scherder, 2014) or their combination (Smith et al., 2013). ...
... In addition, exercise has been shown to significantly increase the number of maturing neurons, indicating that an increase in neurogenesis may be linked to the beneficial effects of exercise ( Van der Borght et al., 2007). Furthermore, an acute period of exercise combined with working memory training has been shown to have synergistic and long-lasting effects on general cognitive performance in mice when voluntary running wheel access was combined with radial arm maze testing (Smith et al., 2013). Therefore, these data may indicate that acute exercise in the form of RAWM acquisition testing may have beneficial but transient effects on both working and reference memory in PB+PER exposed mice. ...
Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component that includes memory impairment as well as neurological and musculoskeletal deficits. Previous studies have shown that in the First Persian Gulf War conflict (1990–1991) exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and permethrin (PER), were key contributors to the etiology of GWI. For this study, we used our previously established mouse model of GW agent exposure (10 days PB+PER) and undertook an extensive lifelong neurobehavioral characterization of the mice from 11 days to 22.5 months post exposure in order to address the persistence and chronicity of effects suffered by the current GWI patient population, 24 years post-exposure. Mice were evaluated using a battery of neurobehavioral testing paradigms, including Open Field Test (OFT), Elevated Plus Maze (EPM), Three Chamber Testing, Radial Arm Water Maze (RAWM), and Barnes Maze (BM) Test. We also carried out neuropathological analyses at 22.5 months post exposure to GW agents after the final behavioral testing. Our results demonstrate that PB+PER exposed mice exhibit neurobehavioral deficits beginning at the 13 months post exposure time point and continuing trends through the 22.5 month post exposure time point. Furthermore, neuropathological changes, including an increase in GFAP staining in the cerebral cortices of exposed mice, were noted 22.5 months post exposure. Thus, the persistent neuroinflammation evident in our model presents a platform with which to identify novel biological pathways, correlating with emergent outcomes that may be amenable to therapeutic targeting. Furthermore, in this work we confirmed our previous findings that GW agent exposure causes neuropathological changes, and have presented novel data which demonstrate increased disinhibition, and lack of social preference in PB+PER exposed mice at 13 months after exposure. We also extended upon our previous work to cover the lifespan of the laboratory mouse using a battery of neurobehavioral techniques.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Exercise is well known to be beneficial to physical health; however, increasing research indicates that physical exercise is also beneficial to brain health and may alleviate symptoms of mental disorders. This book, written by international experts, describes and explores the theory and practice of exercise intervention for different mental disorders across the life span. Drawing on evidence from basic neuroscience research, and enriched with findings from the latest clinical trials, the work provides clear descriptions of current practice and highlights ways to translate this knowledge into pragmatic advice for use in daily practice. The chapters cover a broad range of conditions including neurodevelopmental disorders, depression, anxiety, psychosis and late life neurocognitive disorders. This book is for mental health clinicians including psychiatrists, psychologists, social workers, nurses, as well as internists, paediatricians and geriatricians seeking a comprehensive and individualized approach to treatment.
Substantial improvements in factors such as microbiological quality have been noted in laboratory rodent (mouse [Mus musculus] and rat [Rattus norvegicus]) populations over the last 140 years, since domestication of laboratory strains started. These environmental improvements may have caused Flynn effect-like cognitive changes to occur in these populations, perhaps if these improvements enhanced cognitive plasticity and, consequently, learning potential. While lack of relevant data precludes cross-temporal comparison of cognitive performance means of laboratory rodent populations, it is possible to estimate changes in the proportion of cognitive performance variance attributable to general cognitive ability (GCA) over time. This “differentiation effect” has been found to occur along with the Flynn effect in human populations, suggesting that environmental factors, possibly mediated by their effects on life history speed, may weaken the manifold of GCA across time, allowing for greater cultivation of specialized abilities. Meta-analysis of the literature on mouse and rat cognition yielded 25 mouse studies from which 28 GCA effect sizes could be estimated, and 10 rat studies from which 11 effect sizes could be estimated. Cross-temporal meta-analysis yielded evidence of significant “differentiation effects” spanning approximately a century in both mice and rats, which were independent of age, sex, factor estimation technique, and task number in the case of the mice, and both factor estimation technique and task number in the case of the rats. These trends were also independent of the random effect of strain in both cases. While this is suggestive of the presence of the Flynn effect in captive populations of non-human animals, there are still factors that might be confounding these results. This meta-analysis should be followed up with experimental investigation.
Background:
Time constraints comprise one limiting factor for implementing school-based physical activity programs. The aim of this pilot cluster randomized controlled study was to explore the effects of a cycle ergometer intervention during regular lessons on physical fitness, body composition, and health-related blood parameters.
Methods:
Participants attended one of 2 classes selected from one school, which were randomly assigned to an intervention group (n = 23, 11.2 [0.5] y) consisting of cycling on classroom-based ergometers during 3 lessons per week at a self-selected intensity and a control group (n = 21, 11.3 [0.5] y) not receiving any treatment. Prior to and after the 5-month intervention period, physical fitness (with ventilatory threshold as primary outcome), body composition, and parameters of glucose and lipid metabolism were assessed.
Results:
A significant time × group interaction was revealed for ventilatory threshold (P = .035), respiratory compensation point (P = .038), gross efficiency (P < .001), maximal aerobic power (P = .024), triglycerides (P = .041), and blood glucose levels (P = .041) with benefits for the intervention group. Peak oxygen uptake and body composition were not affected.
Conclusions:
Children's aerobic capacity benefited from the low-intensity school-based cycling intervention, while body composition and most blood parameters were not affected. The intervention using cycle ergometers is a feasible and time-saving strategy to elevate submaximal physical fitness.
حافظه پیش نیاز بسیار مهمی برای انجام مطالبات روزانهاند. حافظه کاری بینایی تقریبا0جزء اصلی تمام فعالیتهای انسان است و نقشی حیاتی درکنترل حرکات درحال اجرا و برخط بازی میکند. سیستم بینایی نقش مهمی در تنظیم بسیاری از رفتارهای انسان از جمله رفتارهای مربوط به حرکت در محیط، جهتیابی و ادراک وضعیت را به عهده دارد و حدود 40 درصد از اطلاعاتی که از طریق حواس مختلف وارد مغز و در آنجا پردازش میشوند، اطلاعات بینایی هستند. بنابراین توجه به اجزای مختلف حافظه کاری بینایی و نقش آنها در حوزههای عملکردی و اجرایی حایز اهمیت بسیاری است. از آنجا که ظرفیت حافظه کاری محدود بوده و در پردازش اطلاعات نقش تعیین کنندهای دارد، تفاوتهای فردی در ظرفیت حافظه کاری در عملکرد افراد منعکس میشود. به نظر میرسد فعالیت ورزشی و تمرین بدنی اثری مثبت بر عملکردهای شناختی افراد داشته باشد. پژوهش حاضر با هدف تاثیر تمرین مهارت ایروبیک بر حافظه کاری بینایی دانشجویان دختر میباشد.روش شناسی: به منظور انجام این پژوهش، 24 نفر دانشجو به شیوه نمونهگیری دردسترس انتخاب شدند. روش پژوهش نیمه آزمایشی با پیش آزمون – پس آزمون است. آموزش حرکات ورزشی ایروبیک بر روی افراد انجام گرفت. ابزار مورد استفاده در این آزمون حافظه بینایی کرسی بلاک است. دادهها با روش آماری توصیفی و استنباطی تی وابسته مورد تجزیه و تحلیل قرار گرفت.نتایج: نتایج پژوهش نشان داد که فعالیت ورزشی باعث افزایش ظرفیت حافظه بینایی شد.نتیجه گیری: نتایج نشان میدهد که شرکت در فعالیت ورزشی، ممکن است عملکردهای شناختی بالاخص حافظه کاری را افزایش دهد.
فعالیت های بدنی و شناختی اثرهای مثبتی بر عملکردهای شناختی دارند، اما به ندرت در ترکیب با يکديگر استفاده شده اند؛ ازاين رو، مطالعۀ حاضر با هدف بررسی اثر فعالیت بدنی با سطوح متفاوت بار شناختی بر امواج مغزی قشر سینگولیت انجام شد. در اين پژوهش نیمه تجربی، 30 دانشجوی دختر کم تجرک با متوسط سنی 1/92 ± 22/63 سال به روش نمونه گیری دردسترس انتخاب شدند و براساس جايگزينی تصادفی در سه گروه 10 نفره (فعالیت بدنی بدون بار شناختی، فعالیت بدنی با بار شناختی و کنترل) قرار گرفتند. نمونه های دو گروه تجربی به مدت 16 جلسه در برنامۀ تمرينی مخصوص به گروه
خود قرار گرفتند، اما گروه کنترل به فعالیت روزانۀ خود پرداختند. قبل و بعد از برنامۀ تمرينی، امواج مغزی با استفاده از دستگاه EEG در حالت استراحت و با چشمان باز ثبت شد و داده های نواحی Fz، Cz و Pz در امواج مغزی دلتا، تتا، آلفا و بتا با استفاده از روش آماری تحلیل کوواريانس چندمتغیره و آزمون تعقیبی بونفرونی در سطح معناداری 0/05 تحلیل شد. نتايج نشان داد که موج مغزی دلتا در ناحیە Fz کاهش بافت و موج مغزی آلفا در ناحیه Pz از نظر آماری افزايش معناداری در شرکت کنندگان هر دو گروه آزمايش داشت، اما تفاوت معناداری بین اثرگذاری فعالیت بدنی با و بدون بار شناختی بر امواج
مغزی قشر سینگولیت مشاهده نشد. براساس يافته های اين مطالعه، بهره گیری از هر نوع فعالیت بدنی
)با و بدون بار شناختی(، احتماالً بتواند شرايط تحريک نورون ها را در سطح قشر سینگولیت مغز فراهم
آورد و باعث ايجاد سازگاری هايی در دستگاه عصبی شود
پژوهش حاضرباهدف بررسی تاثیرآموزش مهارتهاي حرکتی برعملکرد حافظه کاري بینایی دانش آموزان دخترانجام شده است. این پژوهش از نوع نیمه تجربی با طرح پیش آزمون- پس آزمون با گروه کنترل است. نمونه آماري این پژوهش را
دانش آموزان دختر مقطع ابتدایی با دامنه سنی ده تا سیزده سال شهرستان تبریز تشکیل داده اند که با استفاده از نمونه گیري در دسترس انتخاب شده و در دو گروه (12 نفر در گروه آزمایش و 12 نفر در گروه کنترل) جایگزین شدند. در مراحل
پیش آزمون و پس آزمون براي جمع آوري اطلاعات از آزمون حافظه کاري بینایی/فضایی کرسی بلاك استفاده شد. گروه آزمایش به مدت شامل 16 جلسه یک ساعته تحت آموزش مهارتهاي حرکتی هندبال قرار گرفتند. نتایج حاصل از
آزمون تحلیل کوواریانس نشان داد که آموزش مهارتهاي حرکتی و تمرین آنها، موجب افزایش عملکرد حافظه کاري بینایی/فضایی میشود و ظرفیت آن را افزایش میدهد. در واقع، این پژوهش ارتباط و تعامل بین فرایندهاي حرکتی و شناختی بهویژه حافظه کاري را آشکار ساخت.
هدف از پژوهش حاضر، بررسی اثر فعالیت هوازی با و بدون بار شناختی بر شبکۀ هشدار توجه بود. جهت انجام اين پژوهش
نیمه تجربی که شامل دو گروه تجربی و يک گروه کنترل بود، 98 دانشجوی کم تحرک )با میانگین سنی 22/63≠1/92 سال(
به روش نمونه گیری هدفمند انتخاب شده و به صورت مساوی در سه گروه 10نفره جای گرفتند. دو گروه تجربی به مدت 16
جلسه تحت مداخلۀ تمرينی مخصوص گروه خود قرار داشت؛ اما گروه کنترل مداخله ای را دريافت نکرد. شايان ذکر است
که آزمودنی ها قبل و بعد از مداخله به وسیلۀ آزمون شبکه های توجه ارزيابی شدند و داده ها با استفاده از تحلیل کوواريانس
تحلیل گرديد. نتايج نشان میدهد که تفاوت معناداری بین نمرات گروههای تجربی و کنترل در شبکۀ هشدار وجود ندارد.
با توجه به نتايج به نظر میرسد که اثرگذاری ورزش بر شناخت، به ماهیت عملکردهای شناختی و بسترهای مغزی مرتبط
با آنها بستگی داشته باشد
1 بازارگرد جیرسرایی مرجان ، 2 دریافت: تاریخ 27 / 02 / 98 پذیرش: تاریخ 10 / 06 / 98 چکیده متداول از یکی داون سندرم بیماری ترین با ژنتیکی های کم پژوهش هدف است. متوسط تا خفیف ذهنی توان دوره یک تاثیر بررسی حاضر تمرین سوپربرین یوگا بر افزایش ادراک هوش، بینایی-فضایی و پیشرفت تحصیلی و تعادل ایستا کودکان صورت به و آزمایشی نیمه پژوهش این بود. پسر داون سندرم پیش آزمون-پس کنترل گروه با آزمون دانش کلیه پژوهش این آماری جامعه شد. انجام داون سندرم به مبتال پسر آموزان بودند تهران شهر دبستان مقطع. پژوهش کنندگان شرکت 20 استثنایی مدرسه پذیر آموزش داون سندرم پسر سنی میانگین با بهشتی شهید (89 / 0 ± 2 / 8 بودند سال) نمونه روش با که شدند انتخاب دسترس در گیری به و گروه دو در تصادفی صورت 10 آزمایش گروه شدند. داده قرار کنترل و آزمایش نفری 12 تمرینات هفته جمع ابزار دادند. انجام را یوگا سوپربرین پنجم ویرایش کودکان برای وکسلر هوش آزمون اطالعات آوری داده تحلیل و تجزیه برای بود. لک لک ایستای تعادل آزمون و آزمون از های و لوین شاپیروویلک، t مستقل (سیال هوش افزایش بر معنادار تاثیر یوگا سوپربرین تمرینات شد. استفاده اکتسابی نمرات 30 / 0 = P ، 06 / 1 = t ،) (فضایی بینایی ادراک 21 / 0 = P ، 29 / 1 = t (ایستا تعادل و) 65 / 0 = P ، 45 / 0 = t تحصیلی پیشرفت بر ولی نداشت،) (داشت معنادار تاثیر کودکان 02 / 0 = P ، 46 / 2 = t سایر کنار در است بهتر که داد نشان حاضر پژوهش نتایج .) آموزش استفاده داون سندرم کودکان تحصیلی پیشرفت در یوگا سوپربرین تمرینات از تحصیلی متداول های شود.
56 شرکت بود. تهران شهر بهشتی شهید استثنائی ابتدایی مدرسه گام آهسته پسر) پژوهش کنندگان 20 آهس پسران از نفر ته می با گام انحراف و انگین (سنی استاندارد 76 / 0 ± 3 / 8 نمونه روش با که بودند سال) به و شدند انتخاب دسترس در گیری گروه دو در تصادفی صورت 10 قرار کنترل و آزمایش نفری آزمایش گروه شدند. داده 12 تمرینات جلسه یوگای کودکا وکسلر هوش آزمون شامل سنجش ابزارهای دادند. انجام را مغز و ن پنجم یرایش (V-WISC) لک آزمون و (شده اصالح لک MST تجزیه برای بود.) و داده تحلیل آزمون از های t شد. استفاده مستقل ای نتایج اساس بر تمرینات پژوهش، ن یوگای مغز تأثیر (سیال هوش افزایش بر معنادار 81 / 0 = P (فضایی بینایی ادراک ،) 16 / 0 = P ایستا تعادل و) (11 / 0 = P ولی نداشت؛) ب کودکان تحصیلی پیشرفت ر تأثیر (داشت معنادار 04 / 0 = P آموزش سایر کنار در است بهتر که داد نشان حاضر پژوهش نتایج .) تحصیلی متداول های ، تمرین از ات یوگای پیشرفت در مغز شود. استفاده گام آهسته کودکان تحصیلی واژه کلیدی: های یوگای سیال، هوش مغز، بین ادراک فضایی، ایی آهسته تحصیلی، پیشرفت گام استثنائی کودکان توانمندسازی نشریه سال دهم شماره ، 4 (32) ، زمستان 1398 ص ص 36-25
Cardiorespiratory fitness is thought to have beneficial effects on systemic vascular health, in part, by decreasing arterial stiffness. However, in the absence of non-invasive methods, it remains unknown whether this effect extends to the cerebrovasculature. The present study uses a novel pulsed arterial spin labelling (pASL) technique to explore the relationship between cardiorespiratory fitness and arterial compliance of the middle cerebral arteries (MCAC). Other markers of cerebrovascular health, including resting cerebral blood flow (CBF) and cerebrovascular reactivity to CO2 (CVRCO2) were also investigated. Eleven healthy males aged 21 ± 2 years with varying levels of cardiorespiratory fitness (maximal oxygen uptake (
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O2MAX) 38-76 ml/min/kg) underwent MRI scanning at 3 Tesla. Higher
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O2MAX was associated with greater MCAC (R2 = 0.64, p < 0.01) and lower resting grey matter CBF (R2 = 0.75, p < 0.01). However,
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O2MAX was not predictive of global grey matter BOLD-based CVR (R2 = 0.47, p = 0.17) or CBF-based CVR (R2 = 0.19, p = 0.21). The current experiment builds upon the established benefits of exercise on arterial compliance in the systemic vasculature, by showing that increased cardiorespiratory fitness is associated with greater cerebral arterial compliance in early adulthood.
General cognitive ability can be highly heritable in some species, but at the same time, is very malleable. This apparent paradox could potentially be explained by gene–environment interactions and correlations that remain hidden due to experimental limitations on human research and blind spots in animal research. Here, we shed light on this issue by combining the design of a sibling study with an environmental intervention administered to laboratory mice. The analysis included 58 litters of four full-sibling genetically heterogeneous CD-1 male mice, for a total of 232 mice. We separated the mice into two subsets of siblings: a control group (maintained in standard laboratory conditions) and an environmental-enrichment group (which had access to continuous physical exercise and daily exposure to novel environments). We found that general cognitive ability in mice has substantial heritability (24% for all mice) and is also malleable. The mice that experienced the enriched environment had a mean intelligence score that was 0.44 standard deviations higher than their siblings in the control group (equivalent to gains of 6.6 IQ points in humans). We also found that the estimate of heritability changed between groups (55% in the control group compared with non-significant 15% in the enrichment group), analogous to findings in humans across socio-economic status. Unexpectedly, no evidence of gene–environment interaction was detected, and so the change in heritability might be best explained by higher environmental variance in the enrichment group. Our findings, as well as the ‘sibling intervention procedure’ for mice, may be valuable to future research on the heritability, mechanisms and evolution of cognition.
This article is part of the theme issue ‘Causes and consequences of individual differences in cognitive abilities’.
The aim of this study was to examine whether people differed in change in performance across the first five blocks of an online flanker task and whether those trajectories of change were associated with self-reported aerobic or resistance exercise frequency according to age. A total of 8752 men and women aged 13–89 completed a lifestyle survey and five 45-s games (each game was a block of ~46 trials) of an online flanker task. Accuracy of the congruent and incongruent flanker stimuli was analyzed using latent class and growth curve modeling adjusting for time between blocks, whether the blocks occurred on the same or different days, education, smoking, sleep, caffeinated coffee and tea use, and Lumosity training status (“free play” or part of a “daily brain workout”). Aerobic and resistance exercise were unrelated to first block accuracies. For the more cognitively demanding incongruent flanker stimuli, aerobic activity was positively related to the linear increase in accuracy [B=0.577%, 95% confidence interval (CI), 0.112 to 1.25 per day above the weekly mean of 2.8 days] and inversely related to the quadratic deceleration of accuracy gains (B=−0.619% CI, −1.117 to −0.121 per day). An interaction of aerobic activity with age indicated that active participants younger than age 45 had a larger linear increase and a smaller quadratic deceleration compared to other participants. Age moderates the association between self-reported aerobic, but not self-reported resistance, exercise and changes in cognitive control that occur with practice during incongruent presentations across five blocks of a 45-s online, flanker task. (
JINS
, 2015,
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, 802–815)
Human performance on diverse tests of intellect are impacted by a "general" regulatory factor that accounts for up to 50% of the variance between individuals on intelligence tests. Neurobiological determinants of general cognitive abilities are essentially unknown, owing in part to the paucity of animal research wherein neurobiological analyses are possible. We report a methodology with which we have assessed individual differences in the general learning abilities of laboratory mice. Abilities of mice on tests of associative fear conditioning, operant avoidance, path integration, discrimination, and spatial navigation were assessed. Tasks were designed so that each made unique sensory, motor, motivational, and information processing demands on the animals. A sample of 56 genetically diverse outbred mice (CD-1) was used to assess individuals' acquisition on each task. Indicative of a common source of variance, positive correlations were found between individuals' performance on all tasks. When tested on multiple test batteries, the overall performance ranks of individuals were found to be highly reliable and were "normally" distributed. Factor analysis of learning performance variables determined that a single factor accounted for 38% of the total variance across animals. Animals' levels of native activity and body weights accounted for little of the variability in learning, although animals' propensity for exploration loaded strongly (and was positively correlated) with learning abilities. These results indicate that diverse learning abilities of laboratory mice are influenced by a common source of variance and, moreover, that the general learning abilities of individual mice can be specified relative to a sample of peers. Matzel,L.D.,Han YR,Grossman H,Karnik MS,Patel D,Scott N,Specht SM,Gandhi CC.
Numerous recent studies seem to provide evidence for the general intellectual benefits of working memory training. In reviews of the training literature, Shipstead, Redick, and Engle (2010, 2012) argued that the field should treat recent results with a critical eye. Many published working memory training studies suffer from design limitations (no-contact control groups, single measures of cognitive constructs), mixed results (transfer of training gains to some tasks but not others, inconsistent transfer to the same tasks across studies), and lack of theoretical grounding (identifying the mechanisms responsible for observed transfer). The current study compared young adults who received 20 sessions of practice on an adaptive dual n-back program (working memory training group) or an adaptive visual search program (active placebo-control group) with a no-contact control group that received no practice. In addition, all subjects completed pretest, midtest, and posttest sessions comprising multiple measures of fluid intelligence, multitasking, working memory capacity, crystallized intelligence, and perceptual speed. Despite improvements on both the dual n-back and visual search tasks with practice, and despite a high level of statistical power, there was no positive transfer to any of the cognitive ability tests. We discuss these results in the context of previous working memory training research and address issues for future working memory training studies. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Working memory (WM) is a cognitive system that strongly relates to a person's ability to reason with novel information and direct attention to goal-relevant information. Due to the central role that WM plays in general cognition, it has become the focus of a rapidly growing training literature that seeks to affect broad cognitive change through prolonged training on WM tasks. Recent work has suggested that the effects of WM training extend to general fluid intelligence, attentional control, and reductions in symptoms of ADHD. We present a theoretically motivated perspective of WM and subsequently review the WM training literature in light of several concerns. These include (a) the tendency for researchers to define change to abilities using single tasks, (b) inconsistent use of valid WM tasks, (c) no-contact control groups, and (d) subjective measurement of change. The literature review highlights several findings that warrant further research but ultimately concludes that there is a need to directly demonstrate that WM capacity increases in response to training. Specifically, we argue that transfer of training to WM must be demonstrated using a wider variety of tasks, thus eliminating the possibility that results can be explained by task specific learning. Additionally, we express concern that many of the most promising results (e.g., increased intelligence) cannot be readily attributed to changes in WM capacity. Thus, a critical goal for future research is to uncover the mechanisms that lead to transfer of training.
In humans, retrospective studies suggest that habitual physical activity (PA) or cognitive activity (CA) can help maintain or improve cognitive function. Similar findings have been reported using physical exercise in animal studies; however, the exercise paradigms differ markedly in duration and frequency, making extrapolation difficult. Here, the authors present a novel PA and CA paradigm that combines voluntary wheel running with Hebb-Williams and radial arm maze (RAM) training.
A total of 57 male Sprague-Dawley rats were divided into 4 treatment groups: the PA, CA, and combined PA and CA groups and sedentary controls. PA (voluntary wheel running) and CA (Hebb-Williams mazes) consisted of a moderate 2 h/d, 5 d/wk treatment paradigm.
Animals exposed to a combination of PA and CA made significantly fewer working memory errors and exhibited superior choice accuracy when compared with animals exposed to either PA or CA alone in the 8-arm baited configuration of the RAM. Additional analyses revealed that the cognitive improvements were independent of exercise intensity/duration. Assessment of brain-derived neurotrophic factor (BDNF) levels revealed a significant increase in hippocampal BDNF only in the PA-alone group.
A novel combination of PA and CA improves learning and memory abilities independent of activity intensity, BDNF, or phosphorylated cyclic AMP response element binding protein levels. This is the first report of significant changes in cognitive ability using a paradigm involving moderate levels of PA plus cognitive stimulation. An adaptation of this paradigm may be particularly beneficial in slowing the development of mild cognitive impairment and subsequent dementia in elderly people.
Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement.
In both humans and mice, the efficacy of working memory capacity and its related process, selective attention, are each strongly predictive of individuals' aggregate performance in cognitive test batteries [1-9]. Because working memory is taxed during most cognitive tasks, the efficacy of working memory may have a causal influence on individuals' performance on tests of "intelligence" [10, 11]. Despite the attention this has received, supporting evidence has been largely correlational in nature (but see [12]). Here, genetically heterogeneous mice were assessed on a battery of five learning tasks. Animals' aggregate performance across the tasks was used to estimate their general cognitive abilities, a trait that is in some respects analogous to intelligence [13, 14]. Working memory training promoted an increase in animals' selective attention and their aggregate performance on these tasks. This enhancement of general cognitive performance by working memory training was attenuated if its selective attention demands were reduced. These results provide evidence that the efficacy of working memory capacity and selective attention may be causally related to an animal's general cognitive performance and provide a framework for behavioral strategies to promote those abilities. Furthermore, the pattern of behavior reported here reflects a conservation of the processes that regulate general cognitive performance in humans and infrahuman animals.
A growing number of human studies have reported the beneficial influences of acute as well as chronic exercise on cognitive functions. However, neuroimaging investigations into the neural substrates of the effects of acute exercise have yet to be performed. Using multichannel functional near-infrared spectroscopy (fNIRS), we sought cortical activation related to changes in the Stroop interference test, elicited by an acute bout of moderate exercise, in healthy volunteers (N=20). The compactness and portability of fNIRS allowed on-site cortical examination in a laboratory with a cycle ergometer, enabling strict control of the exercise intensity of each subject by assessing their peak oxygen intake (VO2peak). We defined moderate exercise intensity as 50% of a subject's peak oxygen uptake (50%VO2peak). An acute bout of moderate exercise caused significant improvement of cognitive performance reflecting Stroop interference as measured by reaction time. Consistent with previous functional neuroimaging studies, we detected brain activation due to Stroop interference (incongruent minus neutral) in the lateral prefrontal cortices in both hemispheres. This Stroop-interference-related activation was significantly enhanced in the left dorsolateral prefrontal cortex due to the acute bout of moderate exercise. The enhanced activation significantly coincided with the improved cognitive performance. This suggests that the left dorsolateral prefrontal cortex is likely the neural substrate for the improved Stroop performance elicited by an acute bout of moderate exercise. fNIRS, which allows physiological monitoring and functional neuroimaging to be combined, proved to be an effective tool for examining the cognitive effects of exercise.
Improved quality of life (QOL) is a purported benefit of exercise, but few randomized controlled trials and no dose-response trials have been conducted to examine this assertion.
The effect of 50%, 100%, and 150% of the physical activity recommendation on QOL was examined in a 6-month randomized controlled trial. Participants were 430 sedentary postmenopausal women (body mass index range, 25.0-43.0 [calculated as weight in kilograms divided by height in meters squared]) with elevated systolic blood pressure randomized to a nonexercise control group (n = 92) or 1 of 3 exercise groups: exercise energy expenditure of 4 (n = 147), 8 (n = 96), or 12 (n = 95) kilocalories per kilogram of body weight per week. Eight aspects of physical and mental QOL were measured at baseline and month 6 with the use of the Medical Outcomes Study 36-Item Short Form Health Survey.
Change in all mental and physical aspects of QOL, except bodily pain, was dose dependent (trend analyses were significant, and exercise dose was a significant predictor of QOL change; P < .05). Higher doses of exercise were associated with larger improvements in mental and physical aspects of QOL. Controlling for weight change did not attenuate the exercise-QOL association.
Exercise-induced QOL improvements were dose dependent and independent of weight change.
Patients were randomly allocated to a training group and a control group by block randomisation with respect to sex. For nine weeks the training group underwent a programme of systematic aerobic exercise consisting of one hour of training with an instructor three times a week at 50-70% of maximum aerobic capacity. The control group attended occupational therapy while the training group exercised, but otherwise the programme of treatment for the two groups was as similar as possible. The reduction in depression scores and the increase in maximum oxygen uptake were significantly larger in the training group.
mRNA expression of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and hypoxia-inducible factor (HIF) subunits HIF-1alpha and HIF-1beta in human skeletal muscle was studied during endurance exercise at different degrees of oxygen delivery. Muscle biopsies were taken before and after 45 min of one-legged knee-extension exercise performed under conditions of nonrestricted or restricted blood flow (approximately 15-20% lower) at the same absolute workload. Exercise increased VEGF mRNA expression by 178% and HIF-1beta by 340%, but not HIF-1alpha and FGF-2. No significant differences between the restricted and nonrestricted groups were observed. The exercise-induced increase in VEGF mRNA was correlated to the exercise changes in HIF-1alpha and HIF-1beta mRNA. The changes in VEGF, HIF-1alpha, and HIF-1beta mRNAs were correlated to the exercise-induced increase in femoral venous plasma lactate concentration. It is concluded that 1) VEGF but not FGF-2 gene expression is upregulated in human skeletal muscle by a single bout of dynamic exercise and that there is a graded response in VEGF mRNA expression related to the metabolic stress and 2) the increase in VEGF mRNA expression correlates to the changes in both HIF-1alpha and HIF-1beta mRNA.
Although the physiological significance of continued formation of new neurons in the adult mammalian brain is still uncertain, therapeutic strategies aimed to potentiate this process show great promise. Several external factors, including physical exercise, increase the number of new neurons in the adult hippocampus, but underlying mechanisms are not yet known. We recently found that exercise stimulates uptake of the neurotrophic factor insulin-like growth factor I (IGF-I) from the bloodstream into specific brain areas, including the hippocampus. In addition, IGF-I participates in the effects of exercise on hippocampal c-fos expression and mimics several other effects of exercise on brain function. Because subcutaneous administration of IGF-I to sedentary adult rats markedly increases the number of new neurons in the hippocampus, we hypothesized that exercise-induced brain uptake of blood-borne IGF-I could mediate the stimulatory effects of exercise on the adult hippocampus. Thus, we blocked the entrance of circulating IGF-I into the brain by subcutaneous infusion of a blocking IGF-I antiserum to rats undergoing exercise training. The resulting inhibition of brain uptake of IGF-I was paralleled by complete inhibition of exercise-induced increases in the number of new neurons in the hippocampus. Exercising rats receiving an infusion of nonblocking serum showed normal increases in the number of new hippocampal neurons after exercise. Thus, increased uptake of blood-borne IGF-I is necessary for the stimulatory effects of exercise on the number of new granule cells in the adult hippocampus. Taken together with previous results, we conclude that circulating IGF-I is an important determinant of exercise-induced changes in the adult brain.
The authors agree with P. L. Ackerman, M. E. Beier, and M. O. Boyle (2005; see record 2004-22408-002) that working memory capacity (WMC) is not isomorphic with general fluid intelligence (Gf) or reasoning ability. However, the WMC and Gf/reasoning constructs are more strongly associated than Ackerman et al. (2005) indicate, particularly when considering the outcomes of latent-variable studies. The authors' reanalysis of 14 such data sets from 10 published studies, representing more than 3,100 young-adult subjects, suggests a strong correlation between WMC and Gf/reasoning factors (median r=.72), indicating that the WMC and Gf constructs share approximately 50% of their variance. This comment also clarifies the authors' "executive attention" view of WMC, it demonstrates that WMC has greater discriminant validity than Ackerman et al. (2005) implied, and it suggests some future directions and challenges for the scientific study of the convergence of WMC, attention control, and intelligence.
The effects of physical activity on sleep were evaluated in 12-month-old rats. The animals (n = 18) were induced to walk or run for 45 min in a rota-rod treadmill while control mates remained in their home cages. Immediately after the trial, they were left free to sleep for four hours, during which their electroencephalographic activity was recorded. Baseline electroencephalogram showed no differences among groups in sleep parameters and spike wave discharges during wakefulness in all rats. Sleep variables and spike wave discharges remained constant in the controls over times. On the contrary, Student's t-test for paired data indicated a decrease in spike wave discharges in both walking and running rats while paradoxical sleep rose parallel with slow wave sleep in walking animals but declined in running rats, in spite of an increment in slow wave sleep. The results seem to indicate that: i) light exercise improves sleep quality in middle aged rats, provided it is not stressful and ii) physical activity supplies important benefits to waking brain by reducing spike wave discharges.
Although exercise has been shown to relieve depression, little is known about its mechanism or dose-response characteristics. We hypothesized that high intensity progressive resistance training (PRT) would be more effective than either low intensity PRT or standard care by a general practitioner (GP) in depressed elderly persons, and that high intensity PRT would provide superior benefits in quality of life, sleep quality, and self-efficacy.
Sixty community-dwelling adults >60 years with major or minor depression were randomized to supervised high intensity PRT (80% maximum load) or low intensity PRT (20% maximum load) 3 days per week for 8 weeks, or GP care.
A 50% reduction in the Hamilton Rating Scale of Depression score was achieved in 61% of the high intensity, 29% of the low intensity, and 21% of the GP care group (p =.03). Strength gain was directly associated with reduction in depressive symptoms (r = 0.40, p =.004), as was baseline social support network type (F = 3.52, p =.015), whereas personality type, self-efficacy, and locus of control were unrelated to the antidepressant effect. Vitality quality-of-life scale improved more in the high intensity group than in the others (p =.04). Sleep quality improved significantly in all participants (p <.0001), with the greatest relative change in high intensity PRT (p =.05).
High intensity PRT is more effective than is low intensity PRT or GP care for the treatment of older depressed patients.
Up to 50% of an individuals' performance across a wide variety of distinct cognitive tests can be accounted for by a single factor (i.e., "general intelligence"). Despite its ubiquity, the processes or mechanisms regulating this factor are a matter of considerable debate. Although it has been hypothesized that working memory may impact cognitive performance across various domains, tests have been inconclusive due to the difficulty in isolating working memory from its overlapping operations, such as verbal ability. We address this problem using genetically diverse mice, which exhibit a trait analogous to general intelligence. The general cognitive abilities of CD-1 mice were found to covary with individuals' working memory capacity, but not with variations in long-term retention. These results provide evidence that independent of verbal abilities, variations in working memory are associated with general cognitive abilities, and further, suggest a conservation across species of mechanisms and/or processes that regulate cognitive abilities.
Aging causes changes in the hippocampus that may lead to cognitive decline in older adults. In young animals, exercise increases hippocampal neurogenesis and improves learning. We investigated whether voluntary wheel running would benefit mice that were sedentary until 19 months of age. Specifically, young and aged mice were housed with or without a running wheel and injected with bromodeoxyuridine or retrovirus to label newborn cells. After 1 month, learning was tested in the Morris water maze. Aged runners showed faster acquisition and better retention of the maze than age-matched controls. The decline in neurogenesis in aged mice was reversed to 50% of young control levels by running. Moreover, fine morphology of new neurons did not differ between young and aged runners, indicating that the initial maturation of newborn neurons was not affected by aging. Thus, voluntary exercise ameliorates some of the deleterious morphological and behavioral consequences of aging.
Working memory (WM) span tasks-and in particular, counting span, operation span, and reading span tasks-are widely used measures of WM capacity. Despite their popularity, however, there has never been a comprehensive analysis of the merits of WM span tasks as measurement tools. Here, we review the genesis of these tasks and discuss how and why they came to be so influential. In so doing, we address the reliability and validity of the tasks, and we consider more technical aspects of the tasks, such as optimal administration and scoring procedures. Finally, we discuss statistical and methodological techniques that have commonly been used in conjunction with WM span tasks, such as latent variable analysis and extreme-groups designs.
The primary purpose of this narrative review was to evaluate the current literature and to provide further insight into the role physical inactivity plays in the development of chronic disease and premature death. We confirm that there is irrefutable evidence of the effectiveness of regular physical activity in the primary and secondary prevention of several chronic diseases (e.g., cardiovascular disease, diabetes, cancer, hypertension, obesity, depression and osteoporosis) and premature death. We also reveal that the current Health Canada physical activity guidelines are sufficient to elicit health benefits, especially in previously sedentary people. There appears to be a linear relation between physical activity and health status, such that a further increase in physical activity and fitness will lead to additional improvements in health status.
The present study examined whether aerobic fitness training of older humans can increase brain volume in regions associated with age-related decline in both brain structure and cognition.
Fifty-nine healthy but sedentary community-dwelling volunteers, aged 60-79 years, participated in the 6-month randomized clinical trial. Half of the older adults served in the aerobic training group, the other half of the older adults participated in the toning and stretching control group. Twenty young adults served as controls for the magnetic resonance imaging (MRI), and did not participate in the exercise intervention. High spatial resolution estimates of gray and white matter volume, derived from 3D spoiled gradient recalled acquisition MRI images, were collected before and after the 6-month fitness intervention. Estimates of maximal oxygen uptake (VO2) were also obtained.
Significant increases in brain volume, in both gray and white matter regions, were found as a function of fitness training for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning (nonaerobic) control group. As predicted, no significant changes in either gray or white matter volume were detected for our younger participants.
These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans. Furthermore, these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults.
A single factor (i.e., general intelligence) can account for much of an individuals' performance across a wide variety of cognitive tests. However, despite this factor's robustness, the underlying process is still a matter of debate. To address this question, we developed a novel battery of learning tasks to assess the general learning abilities (GLAs) of mice. Using this battery, we previously reported a strong relationship between GLA and a task designed to tax working memory capacity (i.e., resistance to competing demands). Here we further explored this relationship by investigating which aspects of working memory (storage or processing) best predict GLAs in mice. We found that a component of working memory, selective attention, correlated with GLA comparably to working memory capacity. However, this relationship was not found for two other components of working memory, short-term memory capacity and duration. These results provide further evidence that variations in aspects of working memory and executive functions covary with general cognitive abilities.
Human and other animal studies demonstrate that exercise targets many aspects of brain function and has broad effects on overall brain health. The benefits of exercise have been best defined for learning and memory, protection from neurodegeneration and alleviation of depression, particularly in elderly populations. Exercise increases synaptic plasticity by directly affecting synaptic structure and potentiating synaptic strength, and by strengthening the underlying systems that support plasticity including neurogenesis, metabolism and vascular function. Such exercise-induced structural and functional change has been documented in various brain regions but has been best-studied in the hippocampus - the focus of this review. A key mechanism mediating these broad benefits of exercise on the brain is induction of central and peripheral growth factors and growth factor cascades, which instruct downstream structural and functional change. In addition, exercise reduces peripheral risk factors such as diabetes, hypertension and cardiovascular disease, which converge to cause brain dysfunction and neurodegeneration. A common mechanism underlying the central and peripheral effects of exercise might be related to inflammation, which can impair growth factor signaling both systemically and in the brain. Thus, through regulation of growth factors and reduction of peripheral and central risk factors, exercise ensures successful brain function.
Fluid intelligence (Gf) refers to the ability to reason and to solve new problems independently of previously acquired knowledge. Gf is critical for a wide variety of cognitive tasks, and it is considered one of the most important factors in learning. Moreover, Gf is closely related to professional and educational success, especially in complex and demanding environments. Although performance on tests of Gf can be improved through direct practice on the tests themselves, there is no evidence that training on any other regimen yields increased Gf in adults. Furthermore, there is a long history of research into cognitive training showing that, although performance on trained tasks can increase dramatically, transfer of this learning to other tasks remains poor. Here, we present evidence for transfer from training on a demanding working memory task to measures of Gf. This transfer results even though the trained task is entirely different from the intelligence test itself. Furthermore, we demonstrate that the extent of gain in intelligence critically depends on the amount of training: the more training, the more improvement in Gf. That is, the training effect is dosage-dependent. Thus, in contrast to many previous studies, we conclude that it is possible to improve Gf without practicing the testing tasks themselves, opening a wide range of applications.
• cognitive training
• transfer
• individual differences
• executive processes
• control processes
[Two of the authors respond:]
We agree with Herbert Nehrlich that there are many situations in which physicians would benefit from the assistance of health and fitness professionals. It is essential that such advice be sought from professionals who have received formal training and attained national accreditation. In North America1 these would be professionals certified by the Canadian Society for Exercise Physiology or the American College of Sports Medicine. Together, physicians and health and fitness professionals will be able to provide information that is based on sound physiological principles and a clear knowledge of the absolute and relative contraindications to exercise for a variety of populations.
Giuseppe Lippi and associates correctly point out that vigorous exercise may lead to supplemental health gains in sedentary community-dwelling individuals. There is growing evidence to suggest that certain groups may benefit greatly from high-intensity exercise training. We1 have advocated high-intensity exercise training for sedentary individuals2 and patients with cardiovascular disease3 and chronic heart failure.4 However, we are careful to acknowledge that adherence to this form of exercise may be poor and the risk of musculoskeletal injury higher. Therefore, we must weigh carefully the potential advantages and disadvantages of vigorous exercise for each individual client.
As pointed out by Ediriweera Desapriya and colleagues, discussion of the barriers to exercise and innovative means to deliver inclusive and culturally appropriate physical activity interventions is of great importance. Furthermore, more effective lifestyle interventions are required to address the global crisis of physical inactivity. We have worked diligently to address the barriers to physical activity and have taken a transdisciplinary approach to the creation of novel exercise interventions. More work is required to “develop and deliver” inclusive interventions for all, but we believe that our work1,5 is a step in the right direction.
As Rajesh Chauhan and associates point out, the determinants of health are multifactorial and physical activity is not the sole factor influencing health status. However, physical inactivity is an independent predictor of the risk for many chronic diseases and premature mortality. In fact, the risk for chronic disease and premature mortality in North America appears to be about 20% to 50% greater among those with a physically inactive lifestyle.5 Furthermore, physical activity appears to be protective in the presence of other known risk factors for chronic disease. Therefore, there is compelling evidence to support the independent health benefits of physical activity.
Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement
The purpose of this paper is to demonstrate that rats can rapidly learn to locate an object that they can never see, hear, or smell provided it remains in a fixed spatial location relative to distal room cues. Four groups of rats were permitted to escape from opaque water onto a platform which was either just above or just below the water surface, and in either a fixed or varied location. Learning occurred rapidly except for the group for whom the escape platform was below the water surface and moved about from place to place. Transfer tests revealed that a spatial location search strategy was employed by the group for whom the platform was below water but in a fixed location. A second experiment investigated this learning further, revealing instantaneous transfer when the rats were required to approach the platform from a novel starting position. The data of both studies are discussed in relation to recent work on spatial memory in the rat. The concept of the “acuity” of spatial memory is introduced and the procedures used may provide a new approach to comparing spatial memory with classical and instrumental conditioning.
Voluntary wheel-running induces a rapid increase in proliferation and neurogenesis by neural precursors present in the adult rodent hippocampus. In contrast, the responses of hippocampal and other central nervous system neural precursors following longer periods of voluntary physical activity are unclear and are an issue of potential relevance to physical rehabilitation programs. We investigated the effects of a prolonged, 6-week voluntary wheel-running paradigm on neural precursors of the CD1 mouse hippocampus and forebrain. Examination of the hippocampus following 6 weeks of running revealed two to three times as many newly born neurons and 60% more proliferating cells when compared with standard-housed control mice. Among running mice, the number of newly born neurons correlated with the total running distance. To establish the effects of wheel-running on hippocampal precursors dividing during later stages of the prolonged running regime, BrdU was administered after 3 weeks of running and the BrdU-retaining cells were analyzed 18 days later. Quantifications revealed that the effects of wheel-running were maintained in late-stage proliferating cells, as running mice had two to three times as many BrdU-retaining cells within the hippocampal dentate gyrus, and these yielded greater proportions of both mature neurons and proliferative cells. The effects of prolonged wheel-running were also detected beyond the hippocampus. Unlike short-term wheel-running, prolonged wheel-running was associated with higher numbers of proliferating cells within the ventral forebrain subventricular region, a site of age-associated decreases in neural precursor proliferation and neurogenesis. Collectively, these findings indicate that (i) prolonged voluntary wheel-running maintains an increased level of hippocampal neurogenesis whose magnitude is linked to total running performance, and (ii) that it influences multiple neural precursor populations of the adult mouse brain.
Evidence is accumulating that exercise has profound benefits for brain function. Physical activity improves learning and memory in humans and animals. Moreover, an active lifestyle might prevent or delay loss of cognitive function with aging or neurodegenerative disease. Recent research indicates that the effects of exercise on the brain can be enhanced by concurrent consumption of natural products such as omega fatty acids or plant polyphenols. The potential synergy between diet and exercise could involve common cellular pathways important for neurogenesis, cell survival, synaptic plasticity and vascular function. Optimal maintenance of brain health might depend on exercise and intake of natural products.
The role of language in the development of selective inhibitory control was examined in four groups: Children aged 7-9 years, children aged 11-13 years, adults aged 20-27 years, and adults aged 62-76 years. We used a modified stop-signal task in which participants inhibited or executed responses based on a visual signal. Response execution and inhibition were assessed by measurement of reaction times (RTs) and error rates to a go signal and RTs to a stop signal. Four task variations were compared in which subjects named (1) the stimulus, (2) the intended action (go/stop), (3) something irrelevant, or (4) nothing. Results showed different developmental trends for response execution and inhibition across the lifespan. Moreover, response execution was faster and more accurate when subjects named the stimulus instead of the intended action. The increase in response accuracy when naming the stimulus was greatest for children. In contrast to expectations, naming the intended action did not influence response inhibition. Overall, these findings suggest that verbal labeling supports the initiation but not the inhibition of actions.
The effects of a four month aerobic exercise conditioning program on neuropsychological test performance, depression indices, sensory thresholds, and visual acuity of 55-70 year old sedentary individuals were evaluated. Aerobically trained subjects were compared with two age-matched control groups of subjects: those who trained with strength and flexibility exercises and others who were not engaged in a supervised exercise program. The aerobically trained subjects demonstrated significantly greater improvement on the neuropsychological test battery than did either control group. Depression scores, sensory thresholds, and visual acuity were not changed by aerobic exercise. The pattern of results suggests that the effect of aerobic exercise training was on central rather than on peripheral function. We speculate that aerobic exercise promoted increased cerebral metabolic activity with a resultant improvement in neuropsychological test scores.
The search for cellular correlates of learning is a major challenge in neurobiology. The hippocampal formation is important for learning spatial relations. A possible long-lasting consequence of such spatial learning is alteration of the size, shape, or number of excitatory synapses. The dendritic spine density is a good index for the number of hippocampal excitatory synapses. By using laser-scanning confocal microscopy, we observed a significantly increased spine density in CA1 basal dendrites of spatially trained rats when compared to nontrained controls. With unchanged dendritic length, the higher spine density reflects an increased number of excitatory synapses per neuron associated with spatial learning.
Physical inactivity is recognized as a risk factor for coronary artery disease. Regular aerobic physical activity increases exercise capacity and plays a role in both primary and secondary prevention of cardiovascular disease.1 2 3 4 5 The known benefits of regular aerobic exercise and current recommendations for implementation of exercise programs are described in this revised report.6
Exercise training increases cardiovascular functional capacity and decreases myocardial oxygen demand at any level of physical activity in apparently healthy persons as well as in most subjects with cardiovascular disease. Regular physical activity is required to maintain these training effects. The potential risk of physical activity can be reduced by medical evaluation, risk stratification, supervision, and education.4
Exercise can help control blood lipid abnormalities, diabetes, and obesity. In addition, aerobic exercise adds an independent blood pressure–lowering effect in certain hypertensive groups with a decrease of 8 to 10 mm Hg in both systolic and diastolic blood pressure measurements.7 8 9 10 There is a direct relation between physical inactivity and cardiovascular mortality, and physical inactivity is an independent risk factor for the development of coronary artery disease.11 12 13 14 There is a dose-response relation between the amount of exercise performed from approximately 700 to 2000 kcal of energy expenditure per week and all-cause mortality and cardiovascular disease mortality in middle-aged and elderly populations.14 15 The greatest potential for reduced mortality is in the sedentary who become moderately active.15 Most beneficial effects of physical activity on cardiovascular disease mortality can be attained through moderate-intensity activity (40% to 60% of maximal oxygen uptake, depending on age).14 15 16 The activity can be accrued through formal training programs or leisure-time physical activities. Although most of the supporting data are based on studies in men, more recent findings …
Thousands of hippocampal neurons are born in adulthood, suggesting that new cells could be important for hippocampal function. To determine whether hippocampus-dependent learning affects adult-generated neurons, we examined the fate of new cells labeled with the thymidine analog bromodeoxyuridine following specific behavioral tasks. Here we report that the number of adult-generated neurons doubles in the rat dentate gyrus in response to training on associative learning tasks that require the hippocampus. In contrast, training on associative learning tasks that do not require the hippocampus did not alter the number of new cells. These findings indicate that adult-generated hippocampal neurons are specifically affected by, and potentially involved in, associative memory formation.
Acute physical exercise is known to enhance slow-wave sleep (SWS) and reduce paradoxical sleep (PS) in humans. In this study, we examined the effects of moderate physical exercise on sleep in rats.
Young adult Wistar rats underwent a 4-h baseline electroencephalographic (EEG) recording session. The following day, they were induced to walk (0.8 m x min(-1)) or run (4 m x min(-1)) for 45 min in a rota-rod treadmill. Active control rats (ACR) were placed on the locked rota-rod for 45 min, whereas passive control rats (PCR) remained in their home cages. They were then left free to sleep for 4 h during which EEG activity was recorded. Rectal temperature (Tre) was monitored before and after exercise in ACR, walking and running rats (WR and RR, respectively) and at 45 min intervals in PCR.
WR were able to walk for 45 min consecutively whereas in RR performances differed. Posttraining Tre was unchanged in ACR, PCR, and WR and resulted about 1.8 degrees C above baseline in RR. In both WR and RR after exercise i) length of SWS and PS, ii) intensity of SWS (spectral power density in 1-4 Hz range), and iii) propensity for falling asleep were enhanced. Interestingly, there was a more conspicuous increment in PS than SWS. In ACR and PCR there were no changes in sleep.
Due to the complexity of sleep regulation, the interaction of several factors might underlie the observed increment in SWS and PS. Nevertheless, it is interesting that light physical exercise favors sleep and above all a harmonic enhancement of both sleep phases.
A meta-analytic study was conducted to examine the hypothesis that aerobic fitness training enhances the cognitive vitality of healthy but sedentary older adults. Eighteen intervention studies published between 1966 and 2001 were entered into the analysis. Several theoretically and practically important results were obtained. Most important fitness training was found to have robust but selective benefits for cognition, with the largest fitness-induced benefits occurring for executive-control processes. The magnitude of fitness effects on cognition was also moderated by a number of programmatic and methodological factors, including the length of the fitness-training intervention, the type of the intervention, the duration of training sessions, and the gender of the study participants. The results are discussed in terms of recent neuroscientific and psychological data that indicate cognitive and neural plasticity is maintained throughout the life span.
The concept of working memory proposes that a dedicated system maintains and stores information in the short term, and that this system underlies human thought processes. Current views of working memory involve a central executive and two storage systems: the phonological loop and the visuospatial sketchpad. Although this basic model was first proposed 30 years ago, it has continued to develop and to stimulate research and debate. The model and the most recent results are reviewed in this article.
The molecular mechanisms by which physical training improves peripheral and coronary artery disease are poorly understood. Bone marrow-derived endothelial progenitor cells (EPCs) are thought to exert beneficial effects on atherosclerosis, angiogenesis, and vascular repair.
To study the effect of physical activity on the bone marrow, EPCs were quantified by fluorescence-activated cell sorter analysis in mice randomized to running wheels (5.1+/-0.8 km/d, n=12 to 16 per group) or no running wheel. Numbers of EPCs circulating in the peripheral blood of trained mice were enhanced to 267+/-19%, 289+/-22%, and 280+/-25% of control levels after 7, 14, and 28 days, respectively, accompanied by a similar increase of EPCs in the bone marrow and EPCs expanded from spleen-derived mononuclear cells. eNOS-/- mice and wild-type mice treated with N(G)-nitro-l-arginine methyl ester showed lower EPC numbers at baseline and a significantly attenuated increase of EPC in response to physical activity. Exercise NO dependently increased serum levels of vascular endothelial growth factor and reduced the rate of apoptosis in spleen-derived EPCs. Running inhibited neointima formation after carotid artery injury by 22+/-2%. Neoangiogenesis, as assessed in a subcutaneous disc model, was increased by 41+/-16% compared with controls. In patients with stable coronary artery disease (n=19), moderate exercise training for 28 days led to a significant increase in circulating EPCs and reduced EPC apoptosis.
Physical activity increases the production and circulating numbers of EPCs via a partially NO-dependent, antiapoptotic effect that could potentially underlie exercise-related beneficial effects on cardiovascular diseases.
Running activity increases cell proliferation and neurogenesis in the dentate gyrus of adult mice. The present experiment was designed to investigate whether the effect of activity on adult neurogenesis is dependent on the time of day (circadian phase) and the amount of activity. Mice received restricted access to a running wheel (0, 1, or 3 hr) at one of three times of day: the middle of the light phase (i.e., when mice are normally inactive), dark onset (i.e., when mice begin their nocturnal activity), and the middle of the dark period (i.e., when mice are in the middle of their active period). Cell proliferation and net neurogenesis were assessed after incorporation of the thymidine analog bromodeoxyuridine (BrdU) and immunohistochemical detection of BrdU and neuronal markers. Running activity significantly increased cell proliferation, cell survival, and total number of new neurons only in animals with 3 hr of wheel access during the middle of the dark period. Although activity was positively correlated with increased neurogenesis at all time points, the effects were not statistically significant in animals with wheel access at the beginning of the dark period or during the middle of the light period. These data suggest that the influence of exercise on cell proliferation and neurogenesis is modulated by both circadian phase and the amount of daily exercise, thus providing new insight into the complex relationship between physiological and behavioral factors that can mediate adult neuroplasticity.
Physical activity enhances hippocampal function but its effects on neuronal structure remain relatively unexplored outside of the dentate gyrus. Using Golgi impregnation and the lipophilic tracer DiI, we show that long-term voluntary running increases the density of dendritic spines in the entorhinal cortex and hippocampus of adult rats. Exercise was associated with increased dendritic spine density not only in granule neurons of the dentate gyrus, but also in CA1 pyramidal neurons, and in layer III pyramidal neurons of the entorhinal cortex. In the CA1 region, changes in dendritic spine density are accompanied by changes in dendritic arborization and alterations in the morphology of individual spines. These findings suggest that physical activity exerts pervasive effects on neuronal morphology in the hippocampus and one of its afferent populations. These structural changes may contribute to running-induced changes in cognitive function.
Stress and environmental enrichment have opposing effects on cerebral cellular plasticity. Stress-induced disturbances in neuronal and glial plasticity have been implicated in the pathophysiology of affective disorders. Patients with depression often show volume reductions in specific brain regions. The mechanisms behind these changes are not well understood, but animal studies have indicated that increased levels of glucocorticoids and stress have negative impact on the neuronal and glial cell populations. On the contrary, enriched environment and physical activity have positive effects. In this study we have examined the effect of corticosterone (CORT), environmental enrichment (EE) and running on angiogenesis in hippocampus and prefrontal cortex (PFC). We demonstrate a dramatic inhibition in endothelial cell proliferation in these brain regions in CORT-treated rats. Environmental enrichment had the opposite effect and stimulated endothelial cell proliferation both in the hippocampus and in the PFC. Running had a stimulatory effect in hippocampus, but not in the PFC. We suggest that the angiostatic effect of CORT demonstrated in this study might be paralleled in human subjects exposed to high levels of stress hormones for prolonged periods of time. Raised cortisol levels in depressed or old patients could, by reducing endothelial cell formation/turnover, lead to rarefaction and aging of the vascular bed, and as a result, neuronal function could be impaired. It is tempting to speculate that a physically and intellectually active life may protect against stress-induced vascular changes. Therapeutic agents also targeting the cerebral vasculature could consequently constitute a new tool in the combat of stress-related disorders.
Working memory capacity and fluid intelligence are strongly related constructs: comment on Ackerman
- Mj Kane
- Conway Dz Hambrick
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- Boyle
Kane MJ, Hambrick DZ, Conway AR. Working memory capacity and fluid intelligence are strongly related constructs: comment on Ackerman, Beier, and Boyle (2005). Psychol Bull 2005;131:66–71.
Working memory span tasks: a methodological review and user's guide
- Ara Conway
- Mj Kane
- Cet Al
Conway ARA, Kane MJ, Al CET. Working memory span tasks: a methodological
review and user's guide. Psychon Bull Rev 2005;12:769-86.