共查询到20条相似文献,搜索用时 15 毫秒
1.
Sérgio Gomes da Silva Alexandre Aparecido de Almeida Jansen Fernandes Glauber Menezes Lopim Francisco Romero Cabral Débora Amado Scerni Ana Virgínia de Oliveira-Pinto Roberto Lent Ricardo Mario Arida 《PloS one》2016,11(1)
Clinical evidence has shown that physical exercise during pregnancy may alter brain development and improve cognitive function of offspring. However, the mechanisms through which maternal exercise might promote such effects are not well understood. The present study examined levels of brain-derived neurotrophic factor (BDNF) and absolute cell numbers in the hippocampal formation and cerebral cortex of rat pups born from mothers exercised during pregnancy. Additionally, we evaluated the cognitive abilities of adult offspring in different behavioral paradigms (exploratory activity and habituation in open field tests, spatial memory in a water maze test, and aversive memory in a step-down inhibitory avoidance task). Results showed that maternal exercise during pregnancy increased BDNF levels and absolute numbers of neuronal and non-neuronal cells in the hippocampal formation of offspring. No differences in BDNF levels or cell numbers were detected in the cerebral cortex. It was also observed that offspring from exercised mothers exhibited better cognitive performance in nonassociative (habituation) and associative (spatial learning) mnemonic tasks than did offspring from sedentary mothers. Our findings indicate that maternal exercise during pregnancy enhances offspring cognitive function (habituation behavior and spatial learning) and increases BDNF levels and cell numbers in the hippocampal formation of offspring. 相似文献
2.
We examined the association between exercise and weight loss maintenance in a group of 45 previously obese subjects 2 years post very-low-calorie diet (VLCD) to suggest exercise goals for this population. At baseline, subjects weighed a mean 100 kg and had a mean total cholesterol (TC) of 5.8 mmol/L. With VLCD they lost an average 28 kg and decreased their TC by 1.6 mmol/L. Two years post-VLCD their weight and lipids were measured and they completed a physical activity survey (Paffenbarger). Subjects were grouped into tertiles by reported exercise levels: low active (< 850 kcals per week), moderate active (850–1575 kcals per week) and high active (> 1575 kcals per week). Walking accounted for the greatest calorie expenditure (65%). Analysis of variance showed that baseline characteristics and weight and blood lipid changes during the VLCD did not differ (P>0.05) among groups. At follow-up, high active patients maintained significantly greater weight loss, had a lower percent regain and a significantly greater decrease in total cholesterol (P < 0.05) than less active patients. Multiple regression analysis indicated that total exercise calories independently predicted overall weight loss and percent regain (r = 0.66 and r = 0.62, respectively). Exercise calories also predicted total cholesterol change (r=-0.37). The high active group walked more miles (16.2 per week) than the low and moderate active groups (4.8 and 9.1 per week, respectively) and exercised more days per week (5.3 vs. 1.9 and 3.7). The low and moderate active groups regained virtually equal amounts of weight, even though the moderate group expended twice as many kcals per week as the low active group. These data demonstrate that increased exercise levels enhance weight loss maintenance. 相似文献
3.
Jean-Rémi King Alexandre Gramfort Aaron Schurger Lionel Naccache Stanislas Dehaene 《PloS one》2014,9(1)
The brain response to auditory novelty comprises two main EEG components: an early mismatch negativity and a late P300. Whereas the former has been proposed to reflect a prediction error, the latter is often associated with working memory updating. Interestingly, these two proposals predict fundamentally different dynamics: prediction errors are thought to propagate serially through several distinct brain areas, while working memory supposes that activity is sustained over time within a stable set of brain areas. Here we test this temporal dissociation by showing how the generalization of brain activity patterns across time can characterize the dynamics of the underlying neural processes. This method is applied to magnetoencephalography (MEG) recordings acquired from healthy participants who were presented with two types of auditory novelty. Following our predictions, the results show that the mismatch evoked by a local novelty leads to the sequential recruitment of distinct and short-lived patterns of brain activity. In sharp contrast, the global novelty evoked by an unexpected sequence of five sounds elicits a sustained state of brain activity that lasts for several hundreds of milliseconds. The present results highlight how MEG combined with multivariate pattern analyses can characterize the dynamics of human cortical processes. 相似文献
4.
Andr Luís Ferreira Meireles Ethiane Segabinazi Christiano Spindler Tailene Rabello Filipe Mega Gabriela dos Santos Salvalaggio Simone Marcuzzo 《Journal of musculoskeletal & neuronal interactions》2021,21(2):279
Objective:To describe the effects of strength exercise practice during pregnancy on the offspring’s development parameters: growth and motor performance, hippocampal neuroplasticity, and stress levels.Methods:Pregnant Wistar rats were divided into two groups: sedentary and exercised rats. Exercised pregnant rats were subjected to a strength training protocol (vertical ladder climbing) throughout the gestational period. Male offspring’s body weight, length, and head size were evaluated during the neonatal period (postnatal days [P]2–P21), as well as motor milestones during P0–P8. At P8, a set of male pups were subjected to global hippocampal DNA methylation, hippocampal cell proliferation, and plasma corticosterone concentration.Results:Offspring from trained mothers presented a transient change in body morphometric evaluations, no differences in milestone assessments, enhancement of cell proliferation in the dentate gyrus of the hippocampus, and decreased global hippocampal DNA methylation compared with the offspring from sedentary mothers. Furthermore, strength training during pregnancy did not change the corticosterone concentration of exercised mothers and their offspring.Conclusions:These data indicate that strength training can protect offspring’s development and could impact positively on parameters linked to cognitive function. This study provides a greater understanding of the effects of strength exercise practiced during pregnancy on the offspring’s health. 相似文献
5.
The objective of the present study was to investigate whether chronic endurance exercise attenuates the neuroinflammation in the brain of mice with NSE/htau23. In this study, the tau-transgenic (Tg) mouse, Tg-NSE/htau23, which over expresses human Tau23 in its brain, was subjected to chronic exercise for 3 months, from 16 months of age. The brains of Tg mice exhibited increased immunoreactivity and active morphological changes in GFAP (astrocyte marker) and MAC-1 (microglia marker) expression in an age-dependent manner. To identify the effects of chronic exercise on gliosis, the exercised Tg mice groups were treadmill run at a speed of 12 m/min (intermediate exercise group) or 19 m/min (high exercise group) for 1 h/day and 5 days/week during the 3 month period. The neuroinflammatory response characterized by activated astroglia and microglia was significantly repressed in the exercised Tg mice in an exercise intensity-dependent manner. In parallel, chronic exercise in Tg mice reduced the increased expression of TNF-α, IL-6, IL-1β, COX-2, and iNOS. Consistently with these changes, the levels of phospho-p38 and phospho-ERK were markedly downregulated in the brain of Tg mice after exercise. In addition, nuclear NF-κB activity was profoundly reduced after chronic exercise in an exercise intensity-dependent manner. These findings suggest that chronic endurance exercise may alleviate neuroinflammation in the Tau pathology of Alzheimer’s disease. 相似文献
6.
Treadway J.; Dover E. V.; Morse W.; Newcomer L.; Craig B. W. 《Journal of applied physiology》1986,60(5):1700-1703
Evidence in both humans and animals has shown that exercise before or during pregnancy may effect fetal outcome. The purpose of this investigation was to examine the effects of an exercise program on fetal development in the rat. Prior to impregnation one group of animals was exercise-trained on a Quinton shock-stimulus rodent treadmill. The exercised group was trained to run 5 days/wk, for 2.0 h/day at 31 m/min up an 8 degree incline for 8 wk before mating. Following mating the training intensity was reduced to 27 m/min up a 5 degree incline, and the exercise period decreased to 1 h/day. On day 19 of gestation, 24 h postexercise for the trained mothers, the animals were killed in the fed state and the maternal and fetal characteristics were measured. The sedentary controls gained significantly (P less than 0.05) more body weight during pregnancy. This can be attributed to three factors: higher number of fetuses, 14.83 +/- 0.04 vs. 12.2 +/- 0.85 for the trained; larger litter weights, 44.25 +/- 4.97 vs. 26.17 +/- 1.82 g/dam for the trained; and slightly larger lipid stores. In addition to having fewer pups the trained mothers had a greater number of fetal resorptions; 0.9/dam as opposed to 0.17/dam for the sedentary control. Analysis of fetal body composition showed no difference in total body water, protein, or fat between the pups of sedentary and trained dams. The results of this study indicate that exercise training prior to and during pregnancy influences fetal development in the rat. 相似文献
7.
Impact of daily work-load during pregnancy on the microstructure of the rat heart in male offspring.
In two series of experiments the development of body weight, heart weight and the microstructure of the rat heart in the male offspring from exercised and control inactive mothers was followed. In 50-day-old male offspring the total body weight and heart weight did not differ; in 100-day-old male offspring the heart weight was significantly higher in those from mothers exercising daily for 1 hr (run on a treat-mill with the speed 14 to 16 m/min, i.e. mild exercise of an aerobic character) throughout pregnancy. As regards microstructure of the heart, the differences were significant both in younger and older animals. The number of exercised mothers. The capillary: fiber ratio was significantly higher and the diffusion distance significantly shorter in male offspring of exercised mothers. During the prenatal period a favorable effect of work-load for the offspring could be induced more easily even with mild aerobic and quite short daily exercise than later during postnatal life as shown by experiments reported previously. 相似文献
8.
Adiponectin reportedly reduces insulin-resistance. Exercise has also been shown to lessen insulin-resistance, though it is not known whether exercise increases levels of adiponectin and/or its receptors or whether its effects are dependent on exercise intensity and/or frequency. Catecholamine levels have been shown to increase during exercise and to fluctuate based on exercise intensity and duration. In light of this information, we examined the effects of exercise on catecholamine, adiponectin, and adiponectin receptor levels in rats. Our data showed that blood adiponectin levels increased by 150% in animals that exercised at a rate of 30 m/min for 60 min 2 days per week, but not 5 days, per week; no such increase was observed in rats that exercised at a rate of 25 m/min for 30 min. The effects of exercise on adiponectin receptor mRNA were variable, with adiponectin receptor 1 (AdipoR1) levels in muscle increasing up to 4 times while adiponectin receptor 2 (AdipoR2) levels in liver fell to below half in response to exercise at a rate of 25 m/min for 30 min 5 days per week. We also observed that urinary epinephrine levels and plasma lipids were elevated by exercise at a rate of 25 m/min for 30 min 2 days per week. Exercise frequency at a rate of 25 m/min for 30 min correlated with AdipoR1 and AdipoR2 mRNA expression in the muscle and liver, respectively (r=0.640, p<0.05 and r=-0.808, p<0.0005, respectively). Urinary epinephrine levels correlated with AdipoR2 mRNA expression in liver tissues (r=-0.664, p<0.05) in rats that exercised at a rate of 25 m/min for 30 min. Thus, exercise may regulate adiponectin receptor mRNA expression in tissues, which might cause increases in glucose uptake and fatty acid oxidation in the muscle. The effect of exercise on adiponectin levels depends on the specific conditions of the exercise. 相似文献
9.
J. A. Altman S. F. Vaitulevich A. L. Varfolomeev L. B. Shestopalova 《Human physiology》2004,30(1):61-71
The authors consider the results of study of the phenomenon of mismatch negativity (MMN) during exposure to acoustic stimuli simulating fused auditory images with different spatial localization: along the head midline (a standard stimulus used in all series), near either of the ears (lateralized), and moving from the midline to or from an ear. All deviant stimuli evoked the mismatch negativity; the minimum MMN amplitude with the longest latency was observed when the stimulus simulated motion of the auditory image from the midline to either ear. When the deviant auditory images were localized on the left of the midline, the contralateral MMN dominance was more pronounced and responses to various deviant stimuli differed more than when the images were localized on the right. The mismatch negativity as a criterion of discrimination accuracy for signals with different localization features is discussed. 相似文献
10.
《Comparative biochemistry and physiology. A, Comparative physiology》1994,107(3):727-740
We see in this study the effect of high intensity exercise (90% VO2 max) in pregnant rats and their offspring depending on the length of pregnancy. The findings were compared with those obtained for sedentary pregnant rats and non-pregnant rats for similar exercise. This allowed for analysing the isolated effects of exercise (against the sedentary non-pregnant rat control group), of pregnancy and of the interaction between the two factors. For checking the effect of the length of pregnancy, each group of rats was subdivided into those with pregnancy terminated or sacrificed on the seventh, fourteenth or twentieth day of the experiment. VO2 max, post-exertion blood lactic acid level, body weight gain, food intake, feed efficiency, glucose, triglyceride, total cholesterol, total protein and albumin plasmatic concentrations in adult rats, and weight and number of offspring of pregnant rats were determined. Pregnancy increased weight gain and feed efficiency from the first week of the study, accompanied by a greater food intake (from the twelfth day). In the group of pregnant rats subjected to exercise, there was a reduction in weight gain percentage and feed efficiency in the first and third weeks, staying the same in the second week. A greater food intake during the period accompanied this recovery in the second week. In the group of non-pregnant rats subjected to exercise, food intake did not vary. As the weight gain percentage was less in relation to the non-pregnant control group, feed efficiency decreased. Pregnancy induced a drop in blood sugar level starting in the second week, and the exercise performed during pregnancy did not change this behavior. Pregnancy produced, however, an increase in plasmatic concentration of triglycerides and total cholesterol during the third week of pregnancy. Exercise performed by pregnant rats also did not change this behavior, but the increase observed in the third week was less. Exercise performed by non-pregnant rats did not change the blood sugar level and plasmatic concentration of triglycerides and total cholesterol during the entire experiment. Plasmatic concentration of total proteins and albumin showed a drop in the third week of pregnancy, probably due to high fetal use of proteins in this stage. Exercise performed by the pregnant group caused a lower protein drop in the third week, and in the non-pregnant group, determined an increase in plasmatic protein concentrations. The weight of the offspring of mother rats exercised until the end of the second and third weeks of pregnancy was found to be reduced in relation to the sedentary pregnant group. The group exercised until the third week showed a reduction in the number of offspring, indicating a possible fetal reabsorption. These findings confirmed that high intensity exercise can produce deleterious effects on the mother and fetus, especially when applied up to the last stage of pregnancy. 相似文献
11.
J. A. Altman S. Ph. Vaitulevich E. A. Petropavlovskaia L. B. Shestopalova 《Human physiology》2010,36(1):72-79
The spatial resolution of the human auditory system was studied under conditions, where the location of the sound source was
changed according to different temporal patterns of interaural time delay. Two experimental procedures were run in the same
group of subjects: a psychophysical procedure (the transformed staircase method) and an electrophysiological one (which requires
recording of mismatch negativity, the auditory evoked response component). It was established that (1) the value of the mismatch
negativity reflected the degree of spatial deviation of the sound source; (2) the mismatch negativity was elicited even at
minimum (20μs) interaural time delays under both temporal patterns (abrupt azimuth change and gradual sound movement at different
velocities); (3) an abrupt change of the sound source azimuth resulted in a greater mismatch negativity than gradual sound
movement did if the interaural time delay exceeded 40 μs; (4) the discrimination threshold values of the interaural delay
obtained in the psychophysical procedure were greater than the minimum interaural delays that elicited mismatch negativity,
with the exception of the expert listeners, who exhibited no significant difference. 相似文献
12.
M F Mottola J H Plust P D Christopher C L Schachter 《Canadian journal of physiology and pharmacology》1992,70(12):1634-1638
The purpose of the present study was to examine the effects of exercise on maternal glycogen storage patterns and fetal outcome in mature (approximately 12 months of age) Sprague-Dawley rats. The exercise consisted of treadmill running at 30 m.min-1, on a 10 degree incline, for 60 min, 5 days per week, for 4 weeks prior to pregnancy, which continued until day 19 of gestation. In mature animals, chronic exercise increased (p < 0.05) liver glycogen concentration in both pregnant and nonpregnant rats. In pregnant exercised animals, the glycogen concentration of the maternal liver increased almost twofold (p < 0.05) compared with the sedentary pregnant group. There was no difference in the amount of glycogen stored in the gastrocnemius or soleus muscles in response to training, pregnancy, or chronic maternal exercise in the mature rat. In the pregnant groups, there were fewer (p < 0.05) viable fetuses and more (p < 0.05) resorption sites than in young rats. In addition, exercise during pregnancy in the mature animal decreased (p < 0.05) fetal body weight. These results demonstrate that a conflict may exist between maternal exercise and fetal demands for energy in the mature rat. This conflict seems to favour the maternal system, as evidenced by the enhanced maternal liver glycogen storage and the negative effect on fetal growth. 相似文献
13.
Iwamoto J Sato Y Takeda T Matsumoto H 《Journal of musculoskeletal & neuronal interactions》2012,12(3):136-143
A randomized controlled trial was conducted to determine the effect of 6 months of whole body vibration (WBV) exercise on physical function in postmenopausal osteoporotic women treated with alendronate. Fifty-two ambulatory postmenopausal women with osteoporosis (mean age: 74.2 years, range: 51-91 years) were randomly divided into two groups: an exercise group and a control group. A four-minute WBV exercise was performed two days per week only in the exercise group. No exercise was performed in the control group. All the women were treated with alendronate. After 6 months of the WBV exercise, the indices for flexibility, body balance, and walking velocity were significantly improved in the exercise group compared with the control group. The exercise was safe and well tolerated. The reductions in serum alkaline phosphatase and urinary cross-linked N-terminal telopeptides of type I collagen during the 6-month period were comparable between the two groups. The present study showed the benefit and safety of WBV exercise for improving physical function in postmenopausal osteoporotic women treated with alendronate. 相似文献
14.
Walter R. Rogers Anthony M. Coelho K. Dee Carey John L. Ivy Robert E. Shade Stephen P. Easley 《American journal of primatology》1992,27(3):215-224
The objective of this study was to demonstrate the feasibility of using appetitive methods to train adult male olive baboons (Papio cynocephalus anubis), who were socially housed and fitted with indwelling catheter/ transducer systems, to exercise on an inclined, motorized, moving treadmill. All subjects were first trained to walk on a motorized treadmill for 30 min at a speed of approximately 1.6 km/hr on a 0 grade. Upon completion of initial exercise training, six animals were assigned to a low exercise group (LOW), six were assigned to a moderate exercise group (MOD), and six were assigned to a sedentary control group (SED). The LOW group exercised 30 min per day on an elevated treadmill, the MOD group exercised 60 min per day on an elevated treadmill and the SED group did not perform any treadmill exercise. The 12 animals comprising the LOW and MOD groups were exercised 4 days per week and their performance was increased over a subsequent 30-week experimental period. We gradually increased speed and grade demands over several weeks and produced an animal model capable of traveling at speeds up to 5.5 km/hr on a 22% grade and distances up to 3,353 m horizontally and 549 m vertically in a 1-hr session. © 1992 Wiley-Liss, Inc. 相似文献
15.
Westgarth C Liu J Heron J Ness AR Bundred P Gaskell RM German AJ McCune S Dawson S 《PloS one》2012,7(2):e31315
The Avon Longitudinal Study of Parents and Children (ALSPAC) is an observational study of 14,273 UK pregnant singleton mothers in 1990/1991. We examined outcomes of self report of strenuous activity (hours per week) at 18 and 32 weeks of gestation, hours spent in leisure-time physical activities and types, and pre-pregnancy body mass index (BMI); overweight status was defined as pre-pregnancy BMI≥25 and obesity BMI≥30. Pet ownership and activity data were reported for 11,466 mothers. Twenty-five percent of mothers owned at least one dog. There was a positive relationship between participation in activity at least once a week and dog ownership (at 18 weeks, Odds ratio 1.27, 95% confidence interval 1.11-1.44, P<0.001). Dog owners were 50% more likely to achieve the recommended 3 hours activity per week, equivalent to 30 minutes per day, most days of the week (1.53, 1.35-1.72, P<0.001). Dog owners were also more likely to participate in brisk walking activity than those who did not have a dog (compared to no brisk walking 2-6 hrs per week 1.43, 1.23 to 1.67, P<0.001; 7+ hrs per week 1.80, 1.43 to 2.27, P<0.001). However, no association was found with any other types of activities and there was no association between dog ownership and weight status. During the time period studied, pregnant women who had dogs were more active, through walking, than those who did not own dogs. As walking is a low-risk exercise, participation of pregnant women in dog walking activities may be a useful context to investigate as part of a broader strategy to improve activity levels in pregnant women. 相似文献
16.
Regular physical activity has a positive impact on cognition and brain function. Here we investigated if a single bout of exercise can improve motor memory and motor skill learning. We also explored if the timing of the exercise bout in relation to the timing of practice has any impact on the acquisition and retention of a motor skill. Forty-eight young subjects were randomly allocated into three groups, which practiced a visuomotor accuracy-tracking task either before or after a bout of intense cycling or after rest. Motor skill acquisition was assessed during practice and retention was measured 1 hour, 24 hours and 7 days after practice. Differences among groups in the rate of motor skill acquisition were not significant. In contrast, both exercise groups showed a significantly better retention of the motor skill 24 hours and 7 days after practice. Furthermore, compared to the subjects that exercised before practice, the subjects that exercised after practice showed a better retention of the motor skill 7 days after practice. These findings indicate that one bout of intense exercise performed immediately before or after practicing a motor task is sufficient to improve the long-term retention of a motor skill. The positive effects of acute exercise on motor memory are maximized when exercise is performed immediately after practice, during the early stages of memory consolidation. Thus, the timing of exercise in relation to practice is possibly an important factor regulating the effects of acute exercise on long-term motor memory. 相似文献
17.
Objective
To determine the physical activity level and factors influencing physical activity among pregnant urban Chinese women.Methods
This prospective cross-sectional study enrolled 1056 pregnant women (18–44 years of age) in Tianjin, China. Their socio-demographic characteristics were recorded, and the Pregnancy Physical Activity Questionnaire was used to assess their physical activity during pregnancy. The data were analyzed by multinomial logistic regression with adjustment for potential confounders.Results
Median total energy expenditure of pregnant women in each of the three trimesters ranged from 18.50 to 21.90 metabolic equivalents of task (METs) h/day. They expended 1.76–1.85 MET h/day on moderate and vigorous activities and 0.11 MET h/day on exercise. Only 117 of the women (11.1%) met the international guideline for physical activity in pregnancy (≥150 min moderate intensity exercise per week). The most frequent reason given for not being more physically active was the fear of miscarriage. Higher education level (OR: 4.11, 95% CI: 1.59–10.62), habitual exercise before pregnancy (OR: 2.14, 95% CI: 1.39–3.28), and husbands who exercised regularly (OR: 2.21, 95% CI: 1.33–3.67) significantly increased the odds of meeting the guideline (p<0.001). A low pre gravid body mass index (OR: 0.42, 95% CI: 0.20–0.87) significantly decreased the odds (p<0.001).Conclusions
Few urban Chinese pregnant women met the recommended physical activity guideline. They also expended little energy exercising. Future interventions should be based on the clinic environment and targeting family members as well as the subjects. All pregnant women should be targeted, not just those in high-risk groups. 相似文献18.
Rosa BV Firth EC Blair HT Vickers MH Morel PC 《American journal of physiology. Regulatory, integrative and comparative physiology》2011,300(5):R1134-R1141
The effects of increased physical activity during pregnancy on the health of the offspring in later life are unknown. Research in this field requires an animal model of exercise during pregnancy that is sufficiently strenuous to cause an effect but does not elicit a stress response. Previously, we demonstrated that two models of voluntary exercise in the nonpregnant rat, tower climbing and rising to an erect bipedal stance (squat), cause bone modeling without elevating the stress hormone corticosterone. In this study, these same models were applied to pregnant rats. Gravid Wistar rats were randomly divided into three groups: control, tower climbing, and squat exercise. The rats exercised throughout pregnancy and were killed at day 19. Maternal stress was assessed by fecal corticosterone measurement. Maternal bone and soft tissue responses to exercise were assessed by peripheral quantitative computed tomography and dual-energy X-ray absorptiometry. Maternal weight gain during the first 19 days of pregnancy was less in exercised than in nonexercised pregnant control rats. Fecal corticosterone levels did not differ between the three maternal groups. The fetuses responded to maternal exercise in a uterine position-dependent manner. Mid-uterine horn fetuses from the squat exercise group were heavier (P < 0.0001) and longer (P < 0.0001) and had a greater placental weight (P = 0.001) than those from control rats. Fetuses from tower-climbing dams were longer (P < 0.0001) and had heavier placentas (P = 0.01) than those from control rats, but fetal weight did not differ from controls. These models of voluntary exercise in the rat may be useful for future studies of the effects of exercise during pregnancy on the developmental origins of health and disease. 相似文献
19.
Aleksandrov AA Babanin ME Stankevich LN 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2002,88(7):809-816
The effect of stimulus duration on the mismatch negativity in the auditory event-related potentials was used to study the role of mismatch negativity (MMN) in discrimination of short acoustical stimuli. We compared discrimination of different short acoustical stimuli in active variant of "odd ball" paradigm. It was shown that it is possible to discriminate between standard and deviant acoustical stimuli which do not produce MMN in passive condition. It makes possible to estimate behavioural significance of MMN in active discrimination task. If the MMN had not been recorded in passive condition, that leads to an increase of reaction time in active paradigm approximately by 50 ms. 相似文献
20.
The world around us appears stable in spite of our constantly moving head, eyes, and body. How this is achieved by our brain is hardly understood and even less so in the auditory domain. Using electroencephalography and the so-called mismatch negativity, we investigated whether auditory space is encoded in an allocentric (referenced to the environment) or craniocentric representation (referenced to the head). Fourteen subjects were presented with noise bursts from loudspeakers in an anechoic environment. Occasionally, subjects were cued to rotate their heads and a deviant sound burst occurred, that deviated from the preceding standard stimulus either in terms of an allocentric or craniocentric frame of reference. We observed a significant mismatch negativity, i.e., a more negative response to deviants with reference to standard stimuli from about 136 to 188 ms after stimulus onset in the craniocentric deviant condition only. Distributed source modeling with sLORETA revealed an involvement of lateral superior temporal gyrus and inferior parietal lobule in the underlying neural processes. These findings suggested a craniocentric, rather than allocentric, representation of auditory space at the level of the mismatch negativity. 相似文献