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1.
Kostandov EA Farber DA Machinskaia RI Cheremushkin EA Ashkinazi ML Petrenko NE 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2006,56(4):472-480
Changes in the alpha-rhythm synchronization were revealed at different stages of cognitive visual set in 5- to 7-year-old children. We found a clear-cut correlation of these changes with set plasticity. In children with a plastic set, the EEG synchronization between the frontal and other brain regions substantially increased in the period of set-shifting (the actualization stage). At the set extinction stage, after set-shifting has already taken place, the EEG-synchronization becomes minimal. On the contrary, in children who formed a rigid set, EEG coherence considerably increases at the set extinction stage. This finding suggests that the rigid set still affects the cognitive activity even after (judging from oral reports) the set shift has been completed. The age-related differences in cognitive set formation clearly correlate with the time course of the EEG synchronization between the frontal and other brain regions. We think that the ability to form a plastic visual set depends on the frontal cortex maturation, which occurs at the age of 6-7 years, and its age-related effect on the brain cognitive functions. 相似文献
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Kostandov EA Farber DA Cheremushkin EA Machinskaia RI Petrenko NE Ashkinasi ML 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2008,58(1):46-55
Set-forming and set-shifting were studied in children of three age groups: five to six-, six to seven- and nine to ten-year-old. Set effect displayed itself in contrast illusions in most of the subjects (69 of 73). Age differences in set plasticity and in reaction time to a probe stimulus were revealed. Five to six-year-old children formed a more rigid set than older ones. According to EEG coherence function in theta- and alpha-bands and behavioral data, a hypothesis of two systems being involved in set-forming and set-shifting is proposed. These systems are: a fronto-talamic system of selective attention, and a system of cortico-hippocampal connections that are involved in cortical processing of novel visual information and in episodic memory. The age of 6-7 years is shown to be critical in forming a plastic type of cognitive set. 相似文献
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D. Clarke I. Gorman F. Ringholz M. McDermott DW. Cox P. Greally B. Linnane P. Mc Nally 《Respiratory research》2018,19(1):255
Pulmonary aspiration of gastric refluxate (PAGR) has been demonstrated in association with pulmonary inflammation in school aged children with Cystic Fibrosis (CF). We sought to determine if similar findings were present in preschool children. Pepsin was measured in Broncho-alveolar lavage (BAL) fluid collected from clinically stable preschool children with CF and controls. Elevated pepsin levels were found in a subgroup of children with CF, but this was not found to be associated with pulmonary infection, pulmonary inflammation or respiratory or gastrointestinal symptoms. 相似文献
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The glutamate transporter GLT-1 is responsible for the largest proportion of total glutamate transport. Recently, it has been demonstrated that ceftriaxone (CEF) robustly increases GLT-1 expression. In addition, physiological studies have shown that GLT-1 up-regulation strongly affects synaptic plasticity, and leads to an impairment of the prepulse inhibition, a simple form of information processing, thus suggesting that GLT-1 over-expression may lead to dysfunctions of large populations of neurons. To test this possibility, we assessed whether CEF affects cortical electrical activity by using chronic electroencephalographic (EEG) recordings in male WKY rats. Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7-9 Hz) in both frontal and parietal derivations. This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16. In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent. Taken together, these data indicate that GLT-1 up-regulation, by modulating glutamatergic transmission, impairs the activity of widespread neural circuits. In addition, the increased motor activity and prepulse inhibition alterations previously described suggest that neural circuits involved in sensorimotor control are particularly sensitive to GLT-1 up-regulation. 相似文献
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A systems theoretical approach was used to compare possible functional roles of
theta (4--7 Hz) and alpha (8--15 Hz) response components of brain evoked
potentials. These response components were described earlier by Ba\c sar (1980).
We recorded EEG and evoked potentials (EPs) from occipital scalp
locations in 11 subjects. We used auditory
and visual stimuli as inadequate and adequate stimuli, respectively
(``cross-modality' measurements). The combined EEG-EP epochs were analysed in
frequency domain with fast Fourier transform and adaptive digital filters.
Alpha (8--15 Hz) response components turned out to be dependent on whether the
stimulus was adequate or not (median amplitude with
inadequate vs. adequate stimulation: vs. ).
Theta (4--7 Hz) response components were less dependent on stimulus modality
(inadequate vs. adequate stimulation: vs. ).
In EP recordings the occipital alpha response almost disappeared in the
first 250 ms following auditory stimulation. Comparable behaviour was observed
in
similar experiments with recordings from the cat visual cortex (area 17) and
with
occipital magnetoencephalographic recordings.
Taking into account the above-mentioned previous reports on intracranial
recordings in
primary sensory areas of the cat brain and preliminary results of
magnetoencephalographic measurements, we propose the following hypothesis:
alpha responses in a time window of about 250 ms after stimulation might
predominantly
reflect primary sensory processing
whereas the theta responses in the first 250 ms after stimulation might be more
involved in supra-modality
-- or cross-modality -- associative-cognitive processing.
Received: 25 February 1994 / Accepted in revised form: 5
August 1994 相似文献
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A. E. Ferguson N. A. Gibson T. C. Aitchison J. Y. Paton 《BMJ (Clinical research ed.)》1995,310(6988):1161-1164
OBJECTIVE--To investigate how parents use bronchodilator treatment for relief of symptoms when treating their asthmatic preschool children. DESIGN--A commercial electromechanical timer device was attached to a large volume spacer to record the time and date of each use of inhaled bronchodilator over two months. The recorded time and dates were compared with symptoms noted in an asthma diary card. SETTING--Large paediatric teaching hospital in Glasgow. SUBJECTS--29 preschool children with moderately severe asthma attending a specialist paediatric asthma clinic. MAIN OUTCOME MEASURES--Inhaler use measured by the timer device; symptoms and inhaler use recorded by parents in a daily asthma diary. RESULTS--Satisfactory data were obtained in 22 of the 29 children; the median number of study days was 53 (range 18-77). Asthmatic symptoms were recorded on a median of 30 (3-77) days. Bronchodilator was used on a median of 19 (2-73) days, or on 63% (7-100%) of days when symptoms occurred. The median number of puffs used in a day was 1 (range 0-100) and was significantly related to symptom severity in only 14 of the 22 children. In only two of the 22 children was bronchodilator given more frequently than four hourly, and only five children ever used more than 12 puffs a day. CONCLUSIONS--The frequency of parental administration of bronchodilator treatment was variable and not closely related to the parent''s record of symptom severity. Parents often recorded symptoms in their children but did not treat them. 相似文献
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《Chronobiology international》2013,30(8):1101-1108
The timing, duration, and intensity of sleep are determined by the interaction between a sleep-wake-dependent homeostatic process and a sleep-wake-independent, intrinsic, clock-like circadian process. Chronotype represents individual differences in diurnal preferences, which are not only genetically determined but also influenced by social and environmental factors. Thus, the discrepancy between biological and social clocks, so-called “social jetlag”, occurs. Chronotype, social jetlag, and the links between chronotype and behavioral problems are well documented in adults and adolescents. However, such studies on young children are limited. We conducted a survey of sleep and health for preschool children attending kindergarten or childcare centers in Wako, Okayama and Kurashiki cities, Japan, between May and July 2012. A total of 654 children aged 4–6 years (342 boys and 312 girls, with an average age of 4.7 years) were assessed using the Children’s ChronoType Questionnaire and the Strength and Difficulties Questionnaire. Morning (M)-type, neither (N)-type and evening (E)-type accounted for 36.2%, 54.0% and 9.8% of the participants, respectively. The weekday-to-weekend differences in midsleep time – originally proposed as the concept of social jetlag – were 11, 25 and 35?min for M-, N- and E-types, respectively. There was a negative correlation between chronotype and sleep period during weekdays (p?<?0.001) and a positive correlation on weekends (p?<?0.001). The weekday-to-weekend difference in sleep period was 0.5?h for E-types, whereas there was no difference for M-types. Binomial logistic regression analyses were used to examine the links between chronotype and behavioral problems, adjusted for participants’ sex, age, childcare programs and locations. Chronotype was significantly associated with hyperactivity/inattention: N-type (adjusted OR?=?1.74, 95% CI?=?1.03–2.95, p?<?0.05) and E-type (adjusted OR?=?2.47, 95% CI?=?1.18–5.20, p?<?0.05). E-type was significantly associated with conduct problems (adjusted OR?=?2.11, 95% CI?=?1.03–4.31, p?<?0.05) and peer problems (adjusted OR?=?2.75, 95% CI?=?1.18–6.44, p?<?0.05). The results suggest that E-type children are vulnerable to higher social jetlag and more behavioral problems. The immature adjustment function of their endogenous circadian pacemakers may not be able to correct a small but significant social jetlag to synchronize with their social clocks. Furthermore, guidance based on chronobiological evidence is required for parents, teachers and health professionals to help children achieve optimal sleep and reduce behavioral problems. 相似文献
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Hughes SW Lörincz M Cope DW Blethyn KL Kékesi KA Parri HR Juhász G Crunelli V 《Neuron》2004,42(2):253-268
In relaxed wakefulness, the EEG exhibits robust rhythms in the alpha band (8-13 Hz), which decelerate to theta (approximately 2-7 Hz) frequencies during early sleep. In animal models, these rhythms occur coherently with synchronized activity in the thalamus. However, the mechanisms of this thalamic activity are unknown. Here we show that, in slices of the lateral geniculate nucleus maintained in vitro, activation of the metabotropic glutamate receptor (mGluR) mGluR1a induces synchronized oscillations at alpha and theta frequencies that share similarities with thalamic alpha and theta rhythms recorded in vivo. These in vitro oscillations are driven by an unusual form of burst firing that is present in a subset of thalamocortical neurons and are synchronized by gap junctions. We propose that mGluR1a-induced oscillations are a potential mechanism whereby the thalamus promotes EEG alpha and theta rhythms in the intact brain. 相似文献
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Parameters of visuospatial components of mental activity were studied in Mexican children aged 5–6 years with attention deficit disorder. The control group (norm) consisted of preschool children of the same age who attended municipal kindergartens. Neuropsychological methods specially developed and adapted for Mexican children were used. The results testified to prominent impairments of the parameters of spatial analysis and synthesis and of the formation level of object imagery, suggesting functional weakness of the posterior associative (TPO) cortical areas of both hemispheres. The results elucidate specific difficulties in cognitive activity and other impairments in children with attention deficit disorder. 相似文献
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Abdellatif Chakar Ridha Mokni Philip A. Walravens Philippe Chappuis Fanny Bleiberg-Daniel Jean-Louis Mahu Daniel Lemonnier 《Biological trace element research》1993,38(1):97-106
Plasma zinc, copper, and parameters of growth were measured in a group of 116 French preschool children, 2–5 yr-old from low-income
households. Participants were selected on the basis of Z-scores of weight for height (WHZ) and height for age (HAZ). Zinc
and copper concentrations of children with growth impairment (GI), defined by a WHZ and/or HAZ< −1 Z-score, were compared
to those of age, sex, and ethnic origin matched controls (WHZ and HAZ >−1 Z-score). Mean (±SD) plasma zinc concentration was
12.58±1.84 μmol/L in the GI group, and 13.27±1.98 μmol/L in the controls. The difference of the means of paired samples was
0.69±2.34, and by pairedt-test the significance reachedp=0.028. This effect was primarily a result of the weight retarded group (WHZ <−1 Z-score,p<0.009) and to the girls (p<0.05). There were no significant differences in plasma copper concentrations between groups. These results suggest the presence
of marginal zinc deficiency in French preschool children with low weight for height Z-scores. 相似文献
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The present study set out to assess if the different probabilities reported in the literature of obtaining equivalence after baseline training with MTO and OTM protocols could be attributed to individual differences and, if so, whether equivalence formation could be facilitated by using familiar stimuli as nodes. In Experiment 1, 16 preschool children were trained on four sets of 2-choice match-to-sample tasks, eight with a OTM protocol (A-B, A-C, A-D, A-E) and eight with a MTO protocol (B-A, C-A, D-A, E-A). For four OTM and four MTO children only abstract stimuli were used. The other four OTM children and four MTO children received the same training but with familiar stimuli as nodes. All children received tests for equivalence (first) and symmetry (second). In Experiment 2, eight children who served in Experiment 1 participated again, four who had passed the equivalence test, and four who had failed that test. All children received the same baseline training as in Experiment 1 but with the opposite type of nodes (abstract instead of familiar, and vice versa) and training protocol (MTO instead of OTM, and vice versa). The results showed that (a) the children's performances (training and testing) were not affected by the training protocol; (b) equivalence formation occurred more readily when being trained with all abstract stimuli than when familiar stimuli served as nodes; and (c) most children who passed or did not pass the equivalence test in Experiment 1 repeated their performance in Experiment 2, irrespective of the conditions that were used. 相似文献
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Perinatal brain lesion is a risk factor for development, making parents of such children particularly worried about consequences it may have on the child's cognitive and language development. Although literature findings on the outcome of perinatal brain lesion are inconsistent, most of the studies have found a positive general outcome, but also subtle deficits that affect the child's academic success. Since language comprehension and cognitive abilities influence learning abilities at school, we wanted to know how six-year olds who were selected based on pathological ultrasonographical findings (ischemic or hemorrhagic brain lesion) would perform on subtests of Wechsler battery (WISC) and language comprehension measures (Reynell Developmental Language Scale and Peabody Picture Vocabulary Test), compared with controls. The second issue we investigated was whether in children who suffered a perinatal brain lesion cognitive abilities predicted the level of language comprehension in the same way as in children without perinatal brain lesion. The relation between cognitive and linguistic abilities is still a controversial one, and a different relation would mean that these two groups of children have different structure of abilities probably due to perinatal brain lesion. Forty children who suffered a perinatal brain lesion and forty age-matched children without perinatal risk factors were examined. Our results showed that the groups differed more in linguistic than in cognitive variables. Also, the two groups showed different relation patterns between cognitive abilities and language comprehension. Cognitive abilities were statistically significantly associated with language comprehension in children who suffered a perinatal brain lesion, while this association was not statistically significant within the control group. Since a number of participants with perinatal brain lesion had language difficulties, it is presumed that they rely on cognitive abilities in order to overcome and compensate for language shortcomings. 相似文献