joi, 5 ianuarie 2017
Brain training exercises and games: Do they work? (CBC Marketplace)
Can brain training exercises and games prevent memory loss and Alzheimer's? Marketplace tests popular apps
marți, 1 noiembrie 2016
Brain Fitness Exercises. Make you smart, Brain activation.Right Brain exercise
Training your coordination of left and right brain. Challenge for the Brain,
Everything is Possible, Just Train Your Brain - Memorize, Brain Fitness Exercises.
Improves Concentration, Improves Memory, Improves Creativity,
Improves Perceptivity, Improves Talents, Balance Hormone, Rebuilt Character,
Emotional Stability.
Are People Really Left-Brained or Right-Brained?
SciShow explains how some great, Nobel-winning research into the human brain turned into a meme of misunderstanding that lasted for decades.
After watching this, your brain will not be the same | Lara Boyd |
In a classic research-based TEDx Talk, Dr. Lara Boyd describes how neuroplasticity gives you the power to shape the brain you want. Recorded at TEDxVancouver at Rogers Arena on November 14, 2015.
Our knowledge of the brain is evolving at a breathtaking pace, and Dr. Lara Boyd is positioned at the cutting edge of these discoveries. In 2006, she was recruited by the University of British Columbia to become the Canada Research Chair in Neurobiology and Motor Learning. Since that time she has established the Brain Behaviour Lab, recruited and trained over 40 graduate students, published more than 80 papers and been awarded over $5 million in funding.
Dr. Boyd’s efforts are leading to the development of novel, and more effective, therapeutics for individuals with brain damage, but they are also shedding light on broader applications. By learning new concepts, taking advantage of opportunities, and participating in new activities, you are physically changing who you are, and opening up a world of endless possibility.
This talk was given at a TEDx event using the TED conference format but independently organized by a local community.
Can You Really 'Train' Your Brain?
Brain training games claim to improve your memory, attention, and reasoning skills. Some even say they help prevent the onset of dementia. Problem is, they don’t really work
sâmbătă, 20 decembrie 2014
Physical exercise and cognitive function
Physical activity has always existed in human history. Anthropological studies and historical evidence report the existence of this practice since the prehistoric culture, as an integral component of religious, social and cultural expression.
Currently, exercise is an absolute necessity for man, because with the scientific and technological development arising from the industrial revolution and the technological revolution, which we passed, we are faced with high levels of stress, anxiety and physical inactivity undermining the good health the populations of developed and developing countries.
Through this framework, in recent decades has witnessed the growth of interest from individuals and health professionals by regular physical activity (training) in order to meet the physical and cognitive well-being.
Despite the effects of exercise are unquestionable, approximately 60% of Americans do not exercise regularly while 25% do not exercise at all. Among the population segments that traditionally do not engage in physical exercise include the elderly (particularly women) especially those of lower educational level, smokers and obese individuals.
In Brazil, there was a tendency to physical inactivity similar to that observed in the US according to the report of Brazilians living standards, prepared by IBGE (3), indicating that 26% of men under regular physical activity and only 12.7% women are involved in any training programs. When checking the amount of people who exercise at least thirty minutes or more a day, at least three days a week, is 10.8% and 5.2% of men and women respectively.
In the population of the city of São Paulo, in a survey conducted by Mello et al. (2000) (4) on the physical activity and sleep disorders, met physical activity level a little higher than in the rest of the country, as 31.3% of respondents were engaged in some sort of physical activity however, only 36.4% of these individuals have supervision of a qualified professional. In addition, this study found that engaging in physical training programs is higher in higher social classes and that physically active people have lower rates of complaints about sleep disorders. The authors stressed also the importance of public awareness of the benefits of regular and supervised physical exercise and the need for a change in the sedentary lifestyle of the population of the city of São Paulo in order to reduce health-related complaints the individual.
Matsudo et al. (2002) (5), in a study of the population of the State of São Paulo, aimed to investigate the level of physical activity (LPA) of this population, taking into account gender, age, socio-economic and intellectual levels. 2,001 interviews were conducted with 953 men and 1,048 women between 14 and 77 years selected in 29 cities of large, medium and small in the state. Using version 8 of the International Physical Activity Questionnaire (IPAQ) in short form to determine the level of physical activity, it was found that 45.5% of men, 47.3% women and 46.5% of the total sample are people insufficiently active (sedentary and irregularly active).
This prevalent condition of inactivity observed in the general population, especially in the elderly, is a serious threat to the body, stimulating the emergence of chronic degenerative diseases, mood disorder, reducing the physiological and cognitive functions, causing immunosuppression, worsening profile lipid, glucose and sleep quality. Furthermore, a sedentary lifestyle decreases self-esteem, increased anxiety; may also contribute to the worsening of depression symptoms.
Risk factors such as smoking, poor eating habits, alcohol consumption, emotional stress and cognitive problems are also related to physical inactivity (6), so that approximately 250,000 lives are lost each year due to sedentary lifestyle. In this sense, Breslow et al. (1980) presented a list of habits associated with health and longevity, including regular physical exercise, could add between seven and 11 years in the life of a person.
Thus, the adoption of better living habits is an important saving to the public coffers to the extent that it reduces the demand for care in health centers and public hospitals. Thus, encouraging regular physical exercise should be routine in shaping public health policies in the present and in the future.
COGNITIVE FUNCTION
The term cognitive function or cognitive functional system phases of the reporting process, such as perception, learning, memory, attention, vigilance, reasoning and problem solving. Furthermore, psychomotor functioning (reaction time, movement time, speed of performance) has frequently been included in this concept.
Although these cognitive functions are negatively affected by age, as from the third decade of life is loss of neurons with concomitant decline in cognitive performance, based processes crystallized skills such as verbal knowledge and understanding still maintained or improve with aging. In contrast, processes based on fluid skills such as learned but not executed tasks, suffer decline.
Colcombe et al. (2003) found significant declines in the density of neural tissue in aging function in the frontal, parietal and temporal. This can be justified due to a balance of breaks between injury and neuronal repair. The brain is sensitive to many factors that result in damage to neural networks. Similar to other tissues, it has the ability to self-repair / auto-adaptation, or even compensation for the loss of neurons and neural architecture interruptions. When there is an imbalance between neuronal injury and repair, this neuronal plasticity capacity is impaired, then settling the brain aging and dementia.
Over the past decade have identified some risk factors that may increase the predisposition of an individual to cognitive impairment. Among these factors include age, gender, family history, head trauma, educational level, smoking, alcohol consumption, mental stress, nutrition and socialization. More recently factors that can be reversed or mitigated by exercise, such as chronic degenerative diseases, hypercholesterolemia and increase in plasma fibrinogen and physical inactivity, are associated with increased risk of cognitive decline.
The reasons that lead to the appearance of cognitive impairment over the years are not well established; however, some proposals have been raised, among them the reduction of speed in information processing, attention decrease, sensory deficit, reduced working memory capacity, impaired frontal lobe function and neurotransmitter function in addition to the deterioration of movement central and blood-brain barrier.
PHYSICAL EXERCISE AND FUNCTION Cognitive
Epidemiological data suggest that moderately active people have a lower risk of developing mental disorders than sedentary, showing that participation in physical exercise programs exerts benefits in the physical and psychological sphere and that physically active individuals probably have a faster cognitive processing. Nevertheless, Heyn et al. (2004) in a recent meta-analysis also found a significant increase in physical and cognitive performance and positive change in the behavior of older people with cognitive impairment and dementia. Confirming that physical exercise may be important protective against cognitive decline and dementia in the elderly.
Studies on exercise and cognitive function
The magnitude of the effect of exercise on cognition depends on the nature of the cognitive task being evaluated and the type of exercise that was applied. According to Weingarten, this conclusion is based on the complexity of the cognitive task. According to him, the physical training can have a positive impact on cognitive performance of complex tasks, but does not influence the performance of simple tasks. In the study of Gutin (1973), the author suggests that the effects of exercise are mediated by the complexity of the cognitive task and the duration of the exercise, because the reaction time and the optimal level of exercise inducing the alert could be inversely associated with related tasks with choices. The author also suggests that exercise lasting between 45 seconds and two minutes, with heart rate between 90 and 120 beats per minute, would be beneficial for cognitive performance, whereas exercises with six minutes and that increase the heart rate to close 150 beats per minute would be detrimental to cognitive performance.
The observations of the beneficial effects of exercise on cognitive performance, particularly in the elderly, were experimentally performed by several researchers. Van Boxtel, et al. (1997) believe that cognitive tasks could be sensitive to aerobic capacity. Thus, 132 persons aged between 24 and 76 years were submitted to an acute session of submaximal exercise on a cycle ergometer, followed by an extensive neuropsychological battery, including intelligence tests, verbal memory and speed in processing information, which revealed the existence of a interaction between cognitive processing speed tests, age and aerobic capacity.
Hill et al. (1993) also related cognitive performance with aerobic capacity, submitting 87 sedentary elderly to an aerobic training program. They observed positive effects on memory and logic Wechsler Memory Scale (WMS) in the trained group compared with the control that did not train. Another study observed improvement in cognitive functions with increased reaction time, in the range of memory, mood and well-being measures in a group of elderly (N = 94) who participated in an aerobic training program lasting 12 months.
Binder et al. (1999) (30) studied the relationship between performance on psychometric tests and physical performance in elderly, concluded that the speed of cognitive processing is an important component of physical weakness, although it is consistent to consider that there is a small percentage of variance in performance standardized physical tests. The authors reported that cognitive decline with advancing age is more related to global cognitive decline. In particular, would be involved in this process the speed of information processing and the ability to use short-term memory while the information is being processed. This would occur in the elderly, especially in view of the aging central nervous system, thus limiting the adaptive responses that are necessary for its independent operation.
In a study of our group, 23 healthy women between 60 and 70 years (64.3 ± 3.3 years) were subjected to 60 minutes of walking three times a week; as a complementary activity, were subjected to stretching and flexibility exercises. After six months of training, were found improvement in attention, memory, agility and mood pattern for a group of 17 sedentary women. These results suggest that participation in an aerobic exercise program may be seen as an alternative drug not important for successful cognitive improvement in elderly women.
Unlike aerobic studies, studies linking resistance exercises to the possible effects on cognitive functions are still scarce. In one of the few studies on the subject, it was observed that eight weeks of resistance exercise in 46 elderly volunteers promoted improvement in psychological well-being and cognitive functioning (34), suggesting that further studies are needed in order to better understand this relationship between resistance and cognitive function exercise, it is recognized that this type of exercise promotes other important adaptations for this age group, how to mitigate the loss of strength, muscle mass and bone mineral density.
Physical exercise can interfere with cognitive performance for several reasons: a) due to the increase in the levels of neurotransmitters and by changes in brain structures (this would be evident in the comparison of physically active x sedentary individuals); b) the cognitive improvement observed in individuals with mental impairment (based on comparison with healthy subjects); c) the limited improvement achieved by older adults, due to a lower mental / attentional flexibility when compared to a younger group.
In contrast, Etnier et al. (1997) studied several aspects that attempt to explain this complex relationship between physical exercise and cognition, clarifying considerations and assumptions that could help understand and explain some of these disparities. It is believed that the influence of exercise on cognition is inconsistent when small and temporary changes occur in physiological parameters. Thus, the exercise may have little impact on cognition is achieved when acutely, unlike training, which could produce fitness gains and thus be used as an intervention to improve cognitive performance (35). Fabre et al. (2002) compared the effects of physical training and mental training in cognitive function and sought to determine the association of techniques could show better results. The authors studied 32 elderly between 60-76 years who were divided into four groups (aerobic training, mental training, combined aerobic and mental training and control). Aerobic training was conducted in the intensity of heart rate related to the individual ventilatory threshold; have mental training was compounded by Israel's method, the combined group was made up of the activities of aerobic and mental groups and the control group did leisure activities for a period of two months. The aerobic exercise program using the individualized intensity at the ventilatory threshold, and the mental training program resulted in the same degree of improvement in cognitive function, suggesting that the combined use of the two methods can enhance the results because of the improvement of the memory coefficient was higher than that using only one technique. However, the lack of comparison of the results to a group without any type of activity imposes barriers towards definitive conclusions.
Intense exercise and cognitive functions
The protocols developed to investigate the effects of intense exercise on cognitive functions are characterized by the maximal anaerobic demand, causing a state of fatigue and therefore a cognitive decline. These kinds of protocols are short and intense, lasting from a few minutes, usually the cognitive assessment performed immediately after the exercise. Some studies did not succeed in showing the relationship between exercise and comprehensive processes involving perception, sensory or discriminating integration. This is because exercise with high intensity can temporarily slow processes that control the preparation of the response, such as the decrease in cognitive performance.
However, there is some evidence that intensive exercise could facilitate certain aspects of cognition. The exercise performed on a treadmill produced a selective effect on the performance of participants with regard to the analysis and interpretation of maps, because individuals showed reduced ability in interpreting the global information presented on the map; however, short-term memory was significantly improved, leading the authors to conclude that intense physical exercise affects differently the cognitive processing be it high or low level. In addition, associated with the exercise intensity seems that the fitness level plays an important role in determining the impact of intense physical exercise on cognitive function.
Fleury et al. (1981) show that run to exhaustion did not influence the visual perception of young men in a similar way to that observed by Fleury and Bard (1987), for whom there was no influence of exercise with progressive intensity on visual tasks. These results support the hypothesis Wrisberg and Herbert (1976), suggesting that exercise influence of mild, transient processes that control the preparation of the response. This would result possibly due to the rapid recovery of physiological fatigue after the end of the year, as compared to acute and long exercise, which causes decrease in cognitive functioning because of dehydration and depletion of energy reserves.
Alertness induced by physical exercise and cognitive functions
The alert state induced by the exercise is based on the Yerkes-Dodson Law. This law proposes the existence of a relationship between cognitive performance and exercise, similar to what occurs with the alert level, as could occur an initial improvement in performance followed by a decline with increased alert above the resting state. Thus, there is clear evidence of the relationship in inverted "U" between cognition and performance.
However, the results on the alert produced by exercise and cognitive performance are still contradictory. The work conducted by Levitt and Gutin (1971) followed the reaction time and movement in choice-response tasks while subjects walked at equivalent intensities to the heart rates of 115, 145 or 175 beats per minute. The reaction time decreased when the heart rate reached 115 beats returned to baseline at 145 beats and reached lower values to 175 beats. The movement time improved linearly as a function of heart rate.
Other more recent studies confirm the observations of Levitt and Gutin: Salmela and Ndoye (1986), Reilly and Smith (1986) investigated in two steps perceptual-motor and cognitive performance after six minutes of exercise on a cycle ergometer with intensity corresponding to 25, 40 55 to 85% of O2max. In the first, subjects performed perceptual-motor tasks at the end of each exercise intensity; in the second stage, the subjects performed arithmetic tasks using a computer. For both tasks, there was a behavior in inverted "U", with improvement in psychomotor performance every workload increase to approximately 40% of O2max. From this intensity the behavior of this relationship becomes reverse. In relation to cognitive performance, there was a positive result with loads related to 25 and 70% of O2max, but 85% of O2max was perceived deficit in this performance.
Studies McMorris and Graydon (1997) and McMorris et al. (1999) show that the alert state induced by the exercise is limited to information processing speed and has little impact on complex types of decisions encountered during a sporting event. Most of the review studies reports that the alert induced by physical exercise can influence cognition, but not necessarily follows function of inverted "U", as described in other studies, showing the lack of consensus on the matter. In this sense many factors such as type of task to be employed, experience and fitness level of the person must be observed before the comparison and interpretation of results.
By the time the data in the literature can be inferred that physical exercise can, under some conditions, facilitate decision making and solving complex problems; however, there are many mechanisms that act in the interaction between cognitive performance and alertness induced by stress, resulting in wide range of results. With the advent of technology it is expected that new methodologies can help clarify this complex relationship.
Exercise in "steady state" and cognitive functions
The effects of exercise on cognitive function can be divided into acute and chronic (49). Many studies have shown the effects of exercise with intensity between 40 and 80% of O2max and duration of up to 90 minutes in the mood, cognitive function and feelings of well-being. The results so far suggest that aerobic exercise improves the operation of specific stages of information processing, which processes are involved in solving complex problems and processes of care and seem to be more influenced by the submaximal exercise, unlike the initial mechanisms information processing.
Some of these effects in relation to acute exercise of long duration, can be negative, citing dehydration and stress of passive temperature as harmful to the response speed of performance and memory, although not clear the rehydration of the performance impacts cognitive.
The study Simonsick (2003) suggests that low fitness level and low cognitive performance are manifestations of the same disease process and may or may not be changed by the improved physical condition promoted by training.
Nevertheless, several studies have positively associated cardiorespiratory fitness with cognition, especially in measures of attention, executive and visuospatial function.
Because of the lack of consensus on the results in our laboratory investigated the possible physiological, cognitive and mood status and blood viscosity of the elderly before and after a six-month program of aerobic training on a cycle ergometer three times / week with intensity equivalent to LV1. Were used 46 sedentary men aged between 60 and 75 years (66.97 ± 4.80 years). The results showed significant improvement in mood scales, cognitive performance, aerobic capacity and decreased blood viscosity after training period. An important fact in the complex relationship between physical exercise and cognition was reported by Richardson et al. (1998), as reported a case of transient global amnesia (TGA) after an incremental exercise test. After completion of the test the patient in good health for his age, reported confusion, ignorance about how he had come to the site and fluctuation in the mood for four hours after the end of testing. Later, it was revealed, through neurological examinations, an inability to learn and remember verbal material and non-verbal, beyond recall inability to events dating from several hours to several years before the incremental test he underwent. This episode could be related to a temporary dysfunction of the medial temporal lobe, a very important structure for the memory, including the hippocampus. The proposal was that this dysfunction starts in an ischemia caused by vascular changes in the vertebrobasilar arteries.
This work, in contrast to others who have been presented so far, seems to show the role of oxygen as a possible key elements in the relationship exercise and cognition. This would be more evident in light of the conclusions of several studies suggest that neurotransmission as special for cognitive processes. It should be remembered that neurotransmission processes need oxygen for biochemical reactions in the synthesis and degradation of its contributors, demonstrating that the effects of exercise on cognitive function are multifactorial and are associated with changes promoted by exercise in several systems.
MECHANISMS OF PHYSICAL EXERCISE IN THE COGNITIVE FUNCTIONS
The action of physical exercise on cognitive function can be direct or indirect. The mechanisms which act directly increasing the speed of cognitive processing would be an improvement in cerebral circulation and change in neurotransmitter synthesis and degradation. In addition to direct mechanisms, others, such as decreased blood pressure, decrease in LDL and triglyceride levels in the blood plasma and inhibition of platelet aggregation appear to act indirectly by improving these functions and also the overall functional capacity, reflecting in this way increase quality of life.
In addition, scholars have suggested some mechanisms that would be responsible for mediating the effects of exercise on cognitive functions. For synthesis, action and metabolism of neurotransmitters, it is essential to supply adequate amounts of substrates for these reactions. Thus it is believed that physical exercise could increase cerebral blood flow and therefore oxygen and other energy substrates, thus providing improved cognitive function. Another hypothesis that has been formulated with regard to the effects of oxidative stress on the CNS, so that the aerobic physical exercise could increase the activity of antioxidant enzymes in a manner similar to what happens in other tissues such as skeletal muscle, increasing defense capability against damage caused by reactive oxygen species. Furthermore, it can not be ruled out the possibility that exercise in itself, increases the release of several neurotransmitters such as norepinephrine increases in concentrations and their precursors, increasing the concentration of serotonin and b-endorphin after an acute session exercise.
Even after a training period, an acute exercise session increases the concentration of norepinephrine in humans and other animals. These findings are important, since studies in rodents have shown that elevated plasma norepinephrine concentration is related to a better memory. In addition, dopaminergic and noradrenergic synapses appear to be important elements to mnemonic processes.
Moreover, it is possible that regular physical activity influence brain plasticity. Studies such as Isaacs et al. demonstrated that exercise increases vascular density in the cerebellar cortex of rodents subjected to exercise. In addition to maintaining cerebrovascular integrity (avoiding the decrease in cerebral blood flow due to adverse effects) increases the capillarity (68) and the number of dendritic connections.
Spirduso proposed that the exercise could increase the oxidative capacity of the brain, developing a trophic effect on brain centers involved in sensorimotor function. Recent studies have suggested that the central executive function of the type associated with the frontal lobe and hippocampal brain regions can be selectively maintained or improved, in humans, with higher fitness level.
In addition to the assumptions made, others try to explain the mechanisms by which exercise could act improving cognitive functions. Some are related to humoral and neuroendocrine changes caused by exercise, increases as adrenaline, norepinephrine, ACTH, vasopressin and, especially, b-endorphin, which is among the opioids is considered a physiological modulator of memory. These changes could in the long run change the biosynthesis, secretion and / or metabolism of the central systems, working mainly in regions such as the hippocampus, amygdala, medial septum and entorhinal cortex (important regions related mnemonic processes, such as consolidation, storage and recall of information) . With the exception of b-endorphin, catecholamines, vasopressin and ACTH are secreted in proportion to the amount of stress caused by exercise. Therefore, these substances may, by reflex mechanisms to improve the consolidation of memory, thus causing a situation of "dependency state". As the hormones released peripherally present difficulties transferring the blood-brain barrier, the effects of these substances in the memory would be conditioned to the activation of peripheral receptors and / or activity in brain regions weakly protected by the barrier, while some studies suggest that during exercise the barrier blood brain becomes permeable to the action of catecholamines, thus affecting brain metabolism. However, it seems unlikely that these neuromodulators events are solely responsible for the cognitive improvement obtained with the practice of exercise, it is possible that the improved mood and physical conditioning reflect in improved quality of life, helping to obtain the benefit.
Although the mechanisms of exercise on cognitive function have not been clearly elucidated, it can not be left to chance that this improvement is involved in nerve growth factors such as BDNF (brain-derived neurotrophic factor) or other neurogenic stimulators which act in maintenance of brain function and promoting neuronal plasticity.
Currently, exercise is an absolute necessity for man, because with the scientific and technological development arising from the industrial revolution and the technological revolution, which we passed, we are faced with high levels of stress, anxiety and physical inactivity undermining the good health the populations of developed and developing countries.
Through this framework, in recent decades has witnessed the growth of interest from individuals and health professionals by regular physical activity (training) in order to meet the physical and cognitive well-being.
Despite the effects of exercise are unquestionable, approximately 60% of Americans do not exercise regularly while 25% do not exercise at all. Among the population segments that traditionally do not engage in physical exercise include the elderly (particularly women) especially those of lower educational level, smokers and obese individuals.
In Brazil, there was a tendency to physical inactivity similar to that observed in the US according to the report of Brazilians living standards, prepared by IBGE (3), indicating that 26% of men under regular physical activity and only 12.7% women are involved in any training programs. When checking the amount of people who exercise at least thirty minutes or more a day, at least three days a week, is 10.8% and 5.2% of men and women respectively.
In the population of the city of São Paulo, in a survey conducted by Mello et al. (2000) (4) on the physical activity and sleep disorders, met physical activity level a little higher than in the rest of the country, as 31.3% of respondents were engaged in some sort of physical activity however, only 36.4% of these individuals have supervision of a qualified professional. In addition, this study found that engaging in physical training programs is higher in higher social classes and that physically active people have lower rates of complaints about sleep disorders. The authors stressed also the importance of public awareness of the benefits of regular and supervised physical exercise and the need for a change in the sedentary lifestyle of the population of the city of São Paulo in order to reduce health-related complaints the individual.
Matsudo et al. (2002) (5), in a study of the population of the State of São Paulo, aimed to investigate the level of physical activity (LPA) of this population, taking into account gender, age, socio-economic and intellectual levels. 2,001 interviews were conducted with 953 men and 1,048 women between 14 and 77 years selected in 29 cities of large, medium and small in the state. Using version 8 of the International Physical Activity Questionnaire (IPAQ) in short form to determine the level of physical activity, it was found that 45.5% of men, 47.3% women and 46.5% of the total sample are people insufficiently active (sedentary and irregularly active).
This prevalent condition of inactivity observed in the general population, especially in the elderly, is a serious threat to the body, stimulating the emergence of chronic degenerative diseases, mood disorder, reducing the physiological and cognitive functions, causing immunosuppression, worsening profile lipid, glucose and sleep quality. Furthermore, a sedentary lifestyle decreases self-esteem, increased anxiety; may also contribute to the worsening of depression symptoms.
Risk factors such as smoking, poor eating habits, alcohol consumption, emotional stress and cognitive problems are also related to physical inactivity (6), so that approximately 250,000 lives are lost each year due to sedentary lifestyle. In this sense, Breslow et al. (1980) presented a list of habits associated with health and longevity, including regular physical exercise, could add between seven and 11 years in the life of a person.
Thus, the adoption of better living habits is an important saving to the public coffers to the extent that it reduces the demand for care in health centers and public hospitals. Thus, encouraging regular physical exercise should be routine in shaping public health policies in the present and in the future.
COGNITIVE FUNCTION
The term cognitive function or cognitive functional system phases of the reporting process, such as perception, learning, memory, attention, vigilance, reasoning and problem solving. Furthermore, psychomotor functioning (reaction time, movement time, speed of performance) has frequently been included in this concept.
Although these cognitive functions are negatively affected by age, as from the third decade of life is loss of neurons with concomitant decline in cognitive performance, based processes crystallized skills such as verbal knowledge and understanding still maintained or improve with aging. In contrast, processes based on fluid skills such as learned but not executed tasks, suffer decline.
Colcombe et al. (2003) found significant declines in the density of neural tissue in aging function in the frontal, parietal and temporal. This can be justified due to a balance of breaks between injury and neuronal repair. The brain is sensitive to many factors that result in damage to neural networks. Similar to other tissues, it has the ability to self-repair / auto-adaptation, or even compensation for the loss of neurons and neural architecture interruptions. When there is an imbalance between neuronal injury and repair, this neuronal plasticity capacity is impaired, then settling the brain aging and dementia.
Over the past decade have identified some risk factors that may increase the predisposition of an individual to cognitive impairment. Among these factors include age, gender, family history, head trauma, educational level, smoking, alcohol consumption, mental stress, nutrition and socialization. More recently factors that can be reversed or mitigated by exercise, such as chronic degenerative diseases, hypercholesterolemia and increase in plasma fibrinogen and physical inactivity, are associated with increased risk of cognitive decline.
The reasons that lead to the appearance of cognitive impairment over the years are not well established; however, some proposals have been raised, among them the reduction of speed in information processing, attention decrease, sensory deficit, reduced working memory capacity, impaired frontal lobe function and neurotransmitter function in addition to the deterioration of movement central and blood-brain barrier.
PHYSICAL EXERCISE AND FUNCTION Cognitive
Epidemiological data suggest that moderately active people have a lower risk of developing mental disorders than sedentary, showing that participation in physical exercise programs exerts benefits in the physical and psychological sphere and that physically active individuals probably have a faster cognitive processing. Nevertheless, Heyn et al. (2004) in a recent meta-analysis also found a significant increase in physical and cognitive performance and positive change in the behavior of older people with cognitive impairment and dementia. Confirming that physical exercise may be important protective against cognitive decline and dementia in the elderly.
Studies on exercise and cognitive function
The magnitude of the effect of exercise on cognition depends on the nature of the cognitive task being evaluated and the type of exercise that was applied. According to Weingarten, this conclusion is based on the complexity of the cognitive task. According to him, the physical training can have a positive impact on cognitive performance of complex tasks, but does not influence the performance of simple tasks. In the study of Gutin (1973), the author suggests that the effects of exercise are mediated by the complexity of the cognitive task and the duration of the exercise, because the reaction time and the optimal level of exercise inducing the alert could be inversely associated with related tasks with choices. The author also suggests that exercise lasting between 45 seconds and two minutes, with heart rate between 90 and 120 beats per minute, would be beneficial for cognitive performance, whereas exercises with six minutes and that increase the heart rate to close 150 beats per minute would be detrimental to cognitive performance.
The observations of the beneficial effects of exercise on cognitive performance, particularly in the elderly, were experimentally performed by several researchers. Van Boxtel, et al. (1997) believe that cognitive tasks could be sensitive to aerobic capacity. Thus, 132 persons aged between 24 and 76 years were submitted to an acute session of submaximal exercise on a cycle ergometer, followed by an extensive neuropsychological battery, including intelligence tests, verbal memory and speed in processing information, which revealed the existence of a interaction between cognitive processing speed tests, age and aerobic capacity.
Hill et al. (1993) also related cognitive performance with aerobic capacity, submitting 87 sedentary elderly to an aerobic training program. They observed positive effects on memory and logic Wechsler Memory Scale (WMS) in the trained group compared with the control that did not train. Another study observed improvement in cognitive functions with increased reaction time, in the range of memory, mood and well-being measures in a group of elderly (N = 94) who participated in an aerobic training program lasting 12 months.
Binder et al. (1999) (30) studied the relationship between performance on psychometric tests and physical performance in elderly, concluded that the speed of cognitive processing is an important component of physical weakness, although it is consistent to consider that there is a small percentage of variance in performance standardized physical tests. The authors reported that cognitive decline with advancing age is more related to global cognitive decline. In particular, would be involved in this process the speed of information processing and the ability to use short-term memory while the information is being processed. This would occur in the elderly, especially in view of the aging central nervous system, thus limiting the adaptive responses that are necessary for its independent operation.
In a study of our group, 23 healthy women between 60 and 70 years (64.3 ± 3.3 years) were subjected to 60 minutes of walking three times a week; as a complementary activity, were subjected to stretching and flexibility exercises. After six months of training, were found improvement in attention, memory, agility and mood pattern for a group of 17 sedentary women. These results suggest that participation in an aerobic exercise program may be seen as an alternative drug not important for successful cognitive improvement in elderly women.
Unlike aerobic studies, studies linking resistance exercises to the possible effects on cognitive functions are still scarce. In one of the few studies on the subject, it was observed that eight weeks of resistance exercise in 46 elderly volunteers promoted improvement in psychological well-being and cognitive functioning (34), suggesting that further studies are needed in order to better understand this relationship between resistance and cognitive function exercise, it is recognized that this type of exercise promotes other important adaptations for this age group, how to mitigate the loss of strength, muscle mass and bone mineral density.
Physical exercise can interfere with cognitive performance for several reasons: a) due to the increase in the levels of neurotransmitters and by changes in brain structures (this would be evident in the comparison of physically active x sedentary individuals); b) the cognitive improvement observed in individuals with mental impairment (based on comparison with healthy subjects); c) the limited improvement achieved by older adults, due to a lower mental / attentional flexibility when compared to a younger group.
In contrast, Etnier et al. (1997) studied several aspects that attempt to explain this complex relationship between physical exercise and cognition, clarifying considerations and assumptions that could help understand and explain some of these disparities. It is believed that the influence of exercise on cognition is inconsistent when small and temporary changes occur in physiological parameters. Thus, the exercise may have little impact on cognition is achieved when acutely, unlike training, which could produce fitness gains and thus be used as an intervention to improve cognitive performance (35). Fabre et al. (2002) compared the effects of physical training and mental training in cognitive function and sought to determine the association of techniques could show better results. The authors studied 32 elderly between 60-76 years who were divided into four groups (aerobic training, mental training, combined aerobic and mental training and control). Aerobic training was conducted in the intensity of heart rate related to the individual ventilatory threshold; have mental training was compounded by Israel's method, the combined group was made up of the activities of aerobic and mental groups and the control group did leisure activities for a period of two months. The aerobic exercise program using the individualized intensity at the ventilatory threshold, and the mental training program resulted in the same degree of improvement in cognitive function, suggesting that the combined use of the two methods can enhance the results because of the improvement of the memory coefficient was higher than that using only one technique. However, the lack of comparison of the results to a group without any type of activity imposes barriers towards definitive conclusions.
Intense exercise and cognitive functions
The protocols developed to investigate the effects of intense exercise on cognitive functions are characterized by the maximal anaerobic demand, causing a state of fatigue and therefore a cognitive decline. These kinds of protocols are short and intense, lasting from a few minutes, usually the cognitive assessment performed immediately after the exercise. Some studies did not succeed in showing the relationship between exercise and comprehensive processes involving perception, sensory or discriminating integration. This is because exercise with high intensity can temporarily slow processes that control the preparation of the response, such as the decrease in cognitive performance.
However, there is some evidence that intensive exercise could facilitate certain aspects of cognition. The exercise performed on a treadmill produced a selective effect on the performance of participants with regard to the analysis and interpretation of maps, because individuals showed reduced ability in interpreting the global information presented on the map; however, short-term memory was significantly improved, leading the authors to conclude that intense physical exercise affects differently the cognitive processing be it high or low level. In addition, associated with the exercise intensity seems that the fitness level plays an important role in determining the impact of intense physical exercise on cognitive function.
Fleury et al. (1981) show that run to exhaustion did not influence the visual perception of young men in a similar way to that observed by Fleury and Bard (1987), for whom there was no influence of exercise with progressive intensity on visual tasks. These results support the hypothesis Wrisberg and Herbert (1976), suggesting that exercise influence of mild, transient processes that control the preparation of the response. This would result possibly due to the rapid recovery of physiological fatigue after the end of the year, as compared to acute and long exercise, which causes decrease in cognitive functioning because of dehydration and depletion of energy reserves.
Alertness induced by physical exercise and cognitive functions
The alert state induced by the exercise is based on the Yerkes-Dodson Law. This law proposes the existence of a relationship between cognitive performance and exercise, similar to what occurs with the alert level, as could occur an initial improvement in performance followed by a decline with increased alert above the resting state. Thus, there is clear evidence of the relationship in inverted "U" between cognition and performance.
However, the results on the alert produced by exercise and cognitive performance are still contradictory. The work conducted by Levitt and Gutin (1971) followed the reaction time and movement in choice-response tasks while subjects walked at equivalent intensities to the heart rates of 115, 145 or 175 beats per minute. The reaction time decreased when the heart rate reached 115 beats returned to baseline at 145 beats and reached lower values to 175 beats. The movement time improved linearly as a function of heart rate.
Other more recent studies confirm the observations of Levitt and Gutin: Salmela and Ndoye (1986), Reilly and Smith (1986) investigated in two steps perceptual-motor and cognitive performance after six minutes of exercise on a cycle ergometer with intensity corresponding to 25, 40 55 to 85% of O2max. In the first, subjects performed perceptual-motor tasks at the end of each exercise intensity; in the second stage, the subjects performed arithmetic tasks using a computer. For both tasks, there was a behavior in inverted "U", with improvement in psychomotor performance every workload increase to approximately 40% of O2max. From this intensity the behavior of this relationship becomes reverse. In relation to cognitive performance, there was a positive result with loads related to 25 and 70% of O2max, but 85% of O2max was perceived deficit in this performance.
Studies McMorris and Graydon (1997) and McMorris et al. (1999) show that the alert state induced by the exercise is limited to information processing speed and has little impact on complex types of decisions encountered during a sporting event. Most of the review studies reports that the alert induced by physical exercise can influence cognition, but not necessarily follows function of inverted "U", as described in other studies, showing the lack of consensus on the matter. In this sense many factors such as type of task to be employed, experience and fitness level of the person must be observed before the comparison and interpretation of results.
By the time the data in the literature can be inferred that physical exercise can, under some conditions, facilitate decision making and solving complex problems; however, there are many mechanisms that act in the interaction between cognitive performance and alertness induced by stress, resulting in wide range of results. With the advent of technology it is expected that new methodologies can help clarify this complex relationship.
Exercise in "steady state" and cognitive functions
The effects of exercise on cognitive function can be divided into acute and chronic (49). Many studies have shown the effects of exercise with intensity between 40 and 80% of O2max and duration of up to 90 minutes in the mood, cognitive function and feelings of well-being. The results so far suggest that aerobic exercise improves the operation of specific stages of information processing, which processes are involved in solving complex problems and processes of care and seem to be more influenced by the submaximal exercise, unlike the initial mechanisms information processing.
Some of these effects in relation to acute exercise of long duration, can be negative, citing dehydration and stress of passive temperature as harmful to the response speed of performance and memory, although not clear the rehydration of the performance impacts cognitive.
The study Simonsick (2003) suggests that low fitness level and low cognitive performance are manifestations of the same disease process and may or may not be changed by the improved physical condition promoted by training.
Nevertheless, several studies have positively associated cardiorespiratory fitness with cognition, especially in measures of attention, executive and visuospatial function.
Because of the lack of consensus on the results in our laboratory investigated the possible physiological, cognitive and mood status and blood viscosity of the elderly before and after a six-month program of aerobic training on a cycle ergometer three times / week with intensity equivalent to LV1. Were used 46 sedentary men aged between 60 and 75 years (66.97 ± 4.80 years). The results showed significant improvement in mood scales, cognitive performance, aerobic capacity and decreased blood viscosity after training period. An important fact in the complex relationship between physical exercise and cognition was reported by Richardson et al. (1998), as reported a case of transient global amnesia (TGA) after an incremental exercise test. After completion of the test the patient in good health for his age, reported confusion, ignorance about how he had come to the site and fluctuation in the mood for four hours after the end of testing. Later, it was revealed, through neurological examinations, an inability to learn and remember verbal material and non-verbal, beyond recall inability to events dating from several hours to several years before the incremental test he underwent. This episode could be related to a temporary dysfunction of the medial temporal lobe, a very important structure for the memory, including the hippocampus. The proposal was that this dysfunction starts in an ischemia caused by vascular changes in the vertebrobasilar arteries.
This work, in contrast to others who have been presented so far, seems to show the role of oxygen as a possible key elements in the relationship exercise and cognition. This would be more evident in light of the conclusions of several studies suggest that neurotransmission as special for cognitive processes. It should be remembered that neurotransmission processes need oxygen for biochemical reactions in the synthesis and degradation of its contributors, demonstrating that the effects of exercise on cognitive function are multifactorial and are associated with changes promoted by exercise in several systems.
MECHANISMS OF PHYSICAL EXERCISE IN THE COGNITIVE FUNCTIONS
The action of physical exercise on cognitive function can be direct or indirect. The mechanisms which act directly increasing the speed of cognitive processing would be an improvement in cerebral circulation and change in neurotransmitter synthesis and degradation. In addition to direct mechanisms, others, such as decreased blood pressure, decrease in LDL and triglyceride levels in the blood plasma and inhibition of platelet aggregation appear to act indirectly by improving these functions and also the overall functional capacity, reflecting in this way increase quality of life.
In addition, scholars have suggested some mechanisms that would be responsible for mediating the effects of exercise on cognitive functions. For synthesis, action and metabolism of neurotransmitters, it is essential to supply adequate amounts of substrates for these reactions. Thus it is believed that physical exercise could increase cerebral blood flow and therefore oxygen and other energy substrates, thus providing improved cognitive function. Another hypothesis that has been formulated with regard to the effects of oxidative stress on the CNS, so that the aerobic physical exercise could increase the activity of antioxidant enzymes in a manner similar to what happens in other tissues such as skeletal muscle, increasing defense capability against damage caused by reactive oxygen species. Furthermore, it can not be ruled out the possibility that exercise in itself, increases the release of several neurotransmitters such as norepinephrine increases in concentrations and their precursors, increasing the concentration of serotonin and b-endorphin after an acute session exercise.
Even after a training period, an acute exercise session increases the concentration of norepinephrine in humans and other animals. These findings are important, since studies in rodents have shown that elevated plasma norepinephrine concentration is related to a better memory. In addition, dopaminergic and noradrenergic synapses appear to be important elements to mnemonic processes.
Moreover, it is possible that regular physical activity influence brain plasticity. Studies such as Isaacs et al. demonstrated that exercise increases vascular density in the cerebellar cortex of rodents subjected to exercise. In addition to maintaining cerebrovascular integrity (avoiding the decrease in cerebral blood flow due to adverse effects) increases the capillarity (68) and the number of dendritic connections.
Spirduso proposed that the exercise could increase the oxidative capacity of the brain, developing a trophic effect on brain centers involved in sensorimotor function. Recent studies have suggested that the central executive function of the type associated with the frontal lobe and hippocampal brain regions can be selectively maintained or improved, in humans, with higher fitness level.
In addition to the assumptions made, others try to explain the mechanisms by which exercise could act improving cognitive functions. Some are related to humoral and neuroendocrine changes caused by exercise, increases as adrenaline, norepinephrine, ACTH, vasopressin and, especially, b-endorphin, which is among the opioids is considered a physiological modulator of memory. These changes could in the long run change the biosynthesis, secretion and / or metabolism of the central systems, working mainly in regions such as the hippocampus, amygdala, medial septum and entorhinal cortex (important regions related mnemonic processes, such as consolidation, storage and recall of information) . With the exception of b-endorphin, catecholamines, vasopressin and ACTH are secreted in proportion to the amount of stress caused by exercise. Therefore, these substances may, by reflex mechanisms to improve the consolidation of memory, thus causing a situation of "dependency state". As the hormones released peripherally present difficulties transferring the blood-brain barrier, the effects of these substances in the memory would be conditioned to the activation of peripheral receptors and / or activity in brain regions weakly protected by the barrier, while some studies suggest that during exercise the barrier blood brain becomes permeable to the action of catecholamines, thus affecting brain metabolism. However, it seems unlikely that these neuromodulators events are solely responsible for the cognitive improvement obtained with the practice of exercise, it is possible that the improved mood and physical conditioning reflect in improved quality of life, helping to obtain the benefit.
Although the mechanisms of exercise on cognitive function have not been clearly elucidated, it can not be left to chance that this improvement is involved in nerve growth factors such as BDNF (brain-derived neurotrophic factor) or other neurogenic stimulators which act in maintenance of brain function and promoting neuronal plasticity.
Brain training is great ally for the pre-university study and tenders
Technical Neurofeedback, popular in the US, provides greater power of concentration and learning through brain stimulation
Decorate texts and formulas, understand and exercise calculations, have discipline, remain calm in times of trial ...Student Life is not easy, no? Who need to have a high yield as for college or for tenders usually dream of having something that can increase your brain performance and strengthen your memory to the time of trial.
Old acquaintance of Americans for at least 40 years and in constant evolution, the brain training technique, called Neurofeedback, is considered one of the most innovative procedures in the field of neurological and psychological rehabilitation also used for this purpose and promises to make life easier for those who is facing a tough time to get good results in studies.
Designed to enhance brain function, Neurofeedback helps the attention, concentration, memory, emotional issues and decrease the level of stress and anxiety that are causing difficulties in learning and performance on tests.
With Neurofeedback, these irregular electrical brain waves that are triggering the learning difficulties and / or other harm to health of the individual are corrected. "Many people come to the point of not believing they can learn particular material or do well on a test," says the expert.
According to expert, when there is a dysfunction in general waves of some brain regions present very rapid or too slow. The work of Neurofeedback is to regulate and balance these waves. "During the neurological training the brain learns to function properly, balancing the release of neurotransmitters such as serotonin and dopamine [linked to mood, sleep, appetite, attention, concentration, learning, emotions]," explains experts.
Because the technique works
To detect the dysfunction, brain mapping is carried out by means of an electroencephalogram. With the results in hand, the professional defines which patches of brain activity will be needed for that client. Establishes a neurological training protocol for a settlement of brainwave patterns and the correction of impairments found thus enabling a high brain performance.
In this technique, there is the aid of hands to do workouts. The commands are given directly from the customer's brain to the computer by means of electrodes attached to his head. This is how the brain waves are re-educated and learn the way to a high-performance operation.
Disorders with indication for Neurofeedback:
anxiety;
insomnia;
Panic syndrome;
depression;
Disorder Attention Deficit Hyperactivity Disorder;
Obsessive-compulsive disorder;
Post-traumatic stress;
phobias;
Learning difficulties;
Dyslexia and Dyscalculia;
stuttering;
fibromyalgia;
migraine;
Chronic fatigue;
Brain damage due to stroke or traumatic brain injury.
Decorate texts and formulas, understand and exercise calculations, have discipline, remain calm in times of trial ...Student Life is not easy, no? Who need to have a high yield as for college or for tenders usually dream of having something that can increase your brain performance and strengthen your memory to the time of trial.
Old acquaintance of Americans for at least 40 years and in constant evolution, the brain training technique, called Neurofeedback, is considered one of the most innovative procedures in the field of neurological and psychological rehabilitation also used for this purpose and promises to make life easier for those who is facing a tough time to get good results in studies.
Designed to enhance brain function, Neurofeedback helps the attention, concentration, memory, emotional issues and decrease the level of stress and anxiety that are causing difficulties in learning and performance on tests.
With Neurofeedback, these irregular electrical brain waves that are triggering the learning difficulties and / or other harm to health of the individual are corrected. "Many people come to the point of not believing they can learn particular material or do well on a test," says the expert.
According to expert, when there is a dysfunction in general waves of some brain regions present very rapid or too slow. The work of Neurofeedback is to regulate and balance these waves. "During the neurological training the brain learns to function properly, balancing the release of neurotransmitters such as serotonin and dopamine [linked to mood, sleep, appetite, attention, concentration, learning, emotions]," explains experts.
Because the technique works
To detect the dysfunction, brain mapping is carried out by means of an electroencephalogram. With the results in hand, the professional defines which patches of brain activity will be needed for that client. Establishes a neurological training protocol for a settlement of brainwave patterns and the correction of impairments found thus enabling a high brain performance.
In this technique, there is the aid of hands to do workouts. The commands are given directly from the customer's brain to the computer by means of electrodes attached to his head. This is how the brain waves are re-educated and learn the way to a high-performance operation.
Disorders with indication for Neurofeedback:
anxiety;
insomnia;
Panic syndrome;
depression;
Disorder Attention Deficit Hyperactivity Disorder;
Obsessive-compulsive disorder;
Post-traumatic stress;
phobias;
Learning difficulties;
Dyslexia and Dyscalculia;
stuttering;
fibromyalgia;
migraine;
Chronic fatigue;
Brain damage due to stroke or traumatic brain injury.
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