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1.
We studied correlations of the spectral characteristics of EEG with the indices characterizing the level of attention in 60
children (12 to 13 years old). Indices of voluntary attention were measured using a complex of psychological tests, including
a Bourdon’s test (correcture test), a two-stimulus go/no-go test, a computer test (a modification of the Bourdon’s test for
characterization of concentration and stability of attention), and Schulte’s tables. Children manifesting a good working ability
(corresponding to the results of the go/no-go test and correcture test) showed relatively high values of the ratio of spectral
powers (SPs) of the beta 1 and theta rhythms. These ratios were greater in the right hemisphere; this is probably indicative
of a greater contribution of neuronal mechanisms of this hemisphere to providing watchfulness and stability of attention.
Children demonstrating increased impulsivity (according to the results of the go/no-go test) were characterized by low modal
frequencies of the alpha rhythm in the occipital brain regions, while children with relatively high values of this frequency
in various cerebral regions demonstrated high indices of attentiveness and rates of the cognitive processes. Children performing
the test task with especially high accuracy were characterized by high ratios of SPs of the low-frequency beta rhythm vs theta rhythm (mostly in the central and parietal regions of both hemispheres). The approach we have applied can be used for
measuring the objective indices characterizing the state of the attention sphere in children.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 3, pp. 248–256, May–June, 2006. 相似文献
2.
目的: 本研究分析睡眠剥夺对个体选择性注意网络冲突效应和脑电样本熵的影响,探讨睡眠剥夺对大脑注意网络的影响。方法: 25名健康受试者参与36 h完全睡眠剥夺试验。试验于当天9:00开始,于次日21:00结束,试验采用自身前后对照设计。受试者在睡眠剥夺前后分别完成注意网络任务,同步采集受试者的脑电图。用脑电样本熵算法分析脑电图的delta、theta、alpha、beta和gamma频率段的脑电复杂度并对比各频段脑电样本熵在睡眠剥夺前、后的变化。结果: 同睡眠剥夺前比较,睡眠剥夺后与受试者的注意网络冲突效应密切相关的反应时显著下降(P<0.01),正确率显著增加(P<0.01)。脑电样本熵分析发现在beta频率段,与注意网络冲突控制相关的脑电样本熵值在睡眠剥夺后明显增大(P<0.01)。其余脑电频率段脑电样本熵未发现显著差异。结论: 表明完全睡眠剥夺后大脑的注意网络冲突效应降低,表明睡眠剥夺后执行冲突控制能力的下降。 相似文献
3.
《Somatosensory & motor research》2013,30(4):265-277
It is generally accepted that the sensory and affective components of pain may be differentially associated with various acute and chronic diseases, and that some treatment regimens are best directed toward certain aspects of the pain experience. In addition, experimental animal models have been described that presume to assess either the sensory-discriminative aspects of phasic pain or the affective responses associated with tonic pain. The present psychophysical experiment directly compares the perceived intensity and unpleasantness of sensations evoked by four types of experimental noxious stimuli: contact heat, electric shock, ischemic exercise, and cold-pressor pain. A novel pain measurement technique is described that incorporates unbounded magnitude-estimation/category scales; this technique allows precise ratio responses, while minimizing within- and between- subject variability. We observe that, relative to the perceived intensity of the individual stimuli, subjects consistently differentiate among the degrees of unpleasantness evoked by the four stimulus modalities. Ischemic exercise and cold-pressor pain evoke higher estimates of unpleasantness, and thus may better mimic the pain of chronic disease. The relative unpleasantness produced by contact heat is significantly less than that of the other modalities tested, and therefore contact heat stimuli may be ideally suited for assessing sensory-discriminative aspects of pain perception. Possible neurophysiological mechanisms underlying the observed differences in perceived unpleasantness are discussed in relation to the growing body of literature concerning tonic and phasic pain stimuli. 相似文献
4.
We examined the modifying effect of hypokinetic stress on the duration of behavioral phenomena in rats under conditions of
experimentally induced tonic somatic, visceral, acute thermal, and electrostimulation-evoked pain. Stress of the above type
(hypokinetic) was found to modify the pain sensitivity in rats related to all tested types of pain stresses of different etiology.
Changes in the pain sensitivity of the animals under conditions of experimental pain tests depended on the duration of mobility
restriction and could demonstrate opposite directions.
Neirofiziologiya/Neurophysiology, Vol. 39, No. 2, pp. 174–183, March–April, 2007. 相似文献
5.
Ozaki TJ Sato N Kitajo K Someya Y Anami K Mizuhara H Ogawa S Yamaguchi Y 《Cognitive neurodynamics》2012,6(2):185-198
An ambiguous figure such as the Necker cube causes spontaneous perceptual switching (SPS). The mechanism of SPS in multistable
perception has not yet been determined. Although early psychological studies suggested that SPS may be caused by fatigue or
satiation of orientation, the neural mechanism of SPS is still unknown. Functional magnetic resonance imaging (fMRI) has shown
that the dorsal attention network (DAN), which mainly controls voluntary attention, is involved in bistable perception of
the Necker cube. To determine whether neural dynamics along the DAN cause SPS, we performed simultaneous electroencephalography
(EEG) and fMRI during an SPS task with the Necker cube, with every SPS reported by pressing a button. This EEG–fMRI integrated
analysis showed that (a) 3–4 Hz spectral EEG power modulation at fronto-central, parietal, and centro-parietal electrode sites
sequentially appeared from 750 to 350 ms prior to the button press; and (b) activations correlating with the EEG modulation
traveled along the DAN from the frontal to the parietal regions. These findings suggest that slow oscillation initiates SPS
through global dynamics along the attentional system such as the DAN. 相似文献
6.
We studied changes in the power spectra of EEG in the course of sessions of feedback by EEG characteristics (neurofeedback
sessions) and estimated the effects of neurofeedback on psychological and EEG correlates of voluntary attention. Indices of
the latter were estimated using Bourdon’s test (a correcture test) and Schulte’s tables. Twenty-nine reasonably healthy 10-to
13-year-old children took part in the study; they were divided into two groups, an experimental group (n = 12) and a control group (n = 15). The results obtained support the statement on noticeable changes in the functional state of the brain both immediately
in the course of a neurofeedback session and after a course of such trainings. Changes in the ratios of the spectral powers
of the beta1
vs theta rhythms and the low-frequency beta vs theta rhythms were found in EEG recorded from the sensorimotor zone of the right hemisphere (C4). The observed changes in
the spectral characteristics of EEG induced by the course of neurofeedback sessions were accompanied by the improvement of
a few indices of voluntary attention.
Neirofiziologiya/Neurophysiology, Vol. 38, Nos. 5/6, pp. 458–465, September–December, 2006. 相似文献
7.
Shlomit Katz Ziv Kizner Zvy Dubinsky Michael Friedlander 《Journal of applied phycology》2000,12(3-5):535-542
The effect of environmental parameters on the growthof Porphyra linearis gametophytes was examinedunder controlled conditions, and related to themultilinear regression growth model recently developedfor this seaweed under coastal conditions in theeastern Mediterranean. Growth chambers, a gradienttable, special culture devices and analytical methodswere combined for this culture study.The major factors significantly controlling thegrowth rate of the P. linearis gametophytein glass dishes were: photoperiod, temperature, agein culture, photosynthetic photon flux (PPF), salinityand water dynamics. Maximal growth occurred underdaylength of 12 h, medium temperature (15–20 °C), low PPF (70–140 mol photon m-2s-1), ambient salinity (30–40 ppt), 1–3 h ofdaily air exposure, and water velocity of 4 cm s-1.Photosynthesis and respiration rates weredominantly affected by daylength and temperature,while the concentration of pigments was dominantlyaffected by PPF and temperature.These conditions correspond well to the optimalnatural growth environment of this local species andare in agreement with the optimum estimated throughthe recently developed outdoor mathematical growthmodel. 相似文献
8.
José Pires de Lemos Filho Hilton Silveira Pinto Olinto Gomes da Rocha Neto 《International journal of biometeorology》1993,37(4):203-206
In this study we have examined the responses ofHevea plants to low temperatures in growth chambers simulating winter conditions in the tropics. The low temperatures increased the leaf diffusive resistance even with a rise in the leaf temperatures toward the end of day. The total chlorophyll levels were reduced by chilling, with no changes in the chlorophyll a/b ratio. Neither organic solute nor electrolyte leakage were observed at low temperatures. These results explain the low growth rate of plants and the lack of serious chilling symptoms (necrosis) in mature leaves during winter conditions near latitude 22° S in Brazil. 相似文献
9.
A. A. Cherninskii I. G. Zima N. Ye. Makarchouk N. G. Piskorskaya S. A. Kryzhanovskii 《Neurophysiology》2009,41(1):63-70
We recorded EEG in adult volunteers in the course of perception of smells of plant essential oils under conditions of directed
attention. It was found that perception of olfactory information, even in the case of mild intensity of the smells inducing
no aversive effects, correlates with noticeable changes in the EEG characteristics mostly typical of the reaction of nonspecific
EEG activation induced by sensory stimulation and manifested in a decrease in the spectral power, SP, of low-frequency EEG
components (6–10 Hz)). In addition, the SP of relatively high-frequency EEG components (11–25 Hz) increased; this effect was
most pronounced in the occipital regions of the neocortex. Perception of the smells of essential oils was also accompanied
by increases in the coherence of EEG oscillations, most intense in the β2 range (20–25 Hz). Such modifications were maximum
in the left temporal/parietal region; this is interpreted as an indication of the special role of these cortical areas in
the processes of interaction between the neocortical part of the olfactory analyzer and the respective structures of other
analyzer systems. It is hypothesized that such interaction is necessary for the formation of a semantic image of the analyzed
stimuli.
Neirofiziologiya/Neurophysiology, Vol. 41, No. 1, pp. 70–78, January–February, 2009. 相似文献
10.
We studied correlations of the main parameters of evoked EEG potentials (EP) with individual characteristics of attention in children and teenagers. One hundred and one healthy children (dextrals) took part in the tests. Among them, 26 and 30 children were 5 to 7 and 10 to 12 years old, while the third age group included 45 teenagers (15 to 16 years old). We recorded EP and measured the time of a sensorimotor reaction in the following experimental paradigm. Its program provided automated presentation of a pair of acoustic signals, preliminary and imperative; the subject had to perform a motor reaction, pushing a button with the right thumb, with a minimum delay after the second stimulus. Visual feedback signals informed the subject about the successful or inadequate performance of the reaction (time of reaction was shorter than or exceeded a limit value). Indices characterizing the level of attention were estimated using Find and delete and Schultes tables techniques. A well-manifested N2 component of the EP related to the preliminary signal was a specific feature in the group of 5- to 7-year-old children, while the contingent negative variation (CNV) preceding the motor reaction was poorly developed in this group. The best characteristics of attention in these and older (10 to 12 years old) children were typical of subjects with maximally expressed N1-P2 waves. In teenagers, the best attention was typical of subjects with the highest-amplitude P1 and P2 components, CNV, and P300 wave and with the lowest amplitude of the N1 component.Neirofiziologiya/Neurophysiology, Vol. 36, No. 4, pp. 313–321, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
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12.
We examined pain-related behavioral reactions and non-pain behavioral manifestations in mice under conditions of the formalin
test. Levels of analgesia induced by i.p. injections of analgin, microwave irradiation of an antinociceptive acupuncture point
(AP), E-36, or combined application of the above factors were measured. The duration of the pain behavioral reaction (licking
of the injured limb) decreased due to irradiation of the AP with microwaves and to injection of 8.3 mg/kg analgin by 24.3%
and 53.8%, on average, respectively. Combination of injection of analgin in a smaller dose (4.2 mg/kg) and microwave irradiation
of the AP suppressed manifestations of the pain behavioral reaction by 43.4%. Thus, combination of pharmacologically induced
analgesia with the action of microwaves on the antinociceptive AP allows one to significantly decrease the doses of analgesic
preparations necessary to provide a full-level analgesic effect; in such a way, side effects of the respective drugs can be
weakened.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 1, pp. 46–51, January–February, 2006. 相似文献
13.
E. V. Evstaf’eva O. A. Zalata E. V. Repinskaya I. A. Evstaf’eva M. G. Shchegoleva S. L. Tymchenko N. M. Ovsyannikova 《Neurophysiology》2006,38(2):142-148
In 18-to 19-year-old students, the content of a number of microelements, as well as of calcium, in biologically stable tissues
(hair samples) was measured using X-ray fluorescent analysis. In the tested persons, we observed a certain deficit of main
elements (calcium, copper, and zinc), while in some persons the levels of toxic lead and strontium were exceeded. Correlation
analysis of the parameters of EEG potentials (current EEG and evoked and event-related potentials, EPs and ERPs, respectively)
showed the existence of a few significant (or close to those) correlations of the spectral powers of some rhythms and derivatives
of a few indices of the background EEG and more numerous cases of correlations of the parameters of EPs and ERPs (latencies
and amplitudes) with the contents of the studied elements. The physiological importance of metals, according to the number
of characteristics of EEG potentials that correlate with their contents, can be arranged in descending order as follows: As,
Zn > Ca > Cd > Pb > Sr. None of the studied parameters of EEG phenomena correlated with the level of copper. The strength
of correlations varied from weak to mild (0.29 < R < 0.50). The densest correlations were observed for the concentrations of toxic lead and cadmium. With respect to the characteristics
of ERPs, some of the elements under study demonstrated synergism (e.g., lead and arsenic), while others were in an antagonistic
relation (cadmium and calcium).
Neirofiziologiya/Neurophysiology, Vol. 38, No. 2, pp. 167–174, March–April, 2006. 相似文献
14.
I. P. Butkevich G. A. Barr E. A. Vershinina 《Journal of Evolutionary Biochemistry and Physiology》2007,43(1):61-68
In experiments on the 7-day old female and male Long-Evans rat pups, for the first time, there was studied effect of prenatal (immobilization) stress on dynamics of nociceptive behavioral response caused by an inflammatory focus. The nociceptive sensitivity was evaluated for 1 h by the number of the flexion-shaking patterns organized at the spinal level in response to injection of formalin (10%, 10 μl) to the posterior leg sole. Control rat pups were not submitted to any prenatal stress; in these animals the response in the formalin test was found to be represented by one phase. It the prenatally stressed rat pups the studied patterns were organized into two phases characteristic of the definitive type of response. At the period between them (during interphase), the nociceptive behavior was absent. At the second, tonic phase the number of flexion-shakings in the prenatally stressed males was statistically significantly higher than in the prenatally stressed females, which indicates a sensitization of the neurons involved in the tonic pain chains in male individuals. Thus, the data obtained on prenatally stressed animals confirm the previous data about immaturity of the mechanisms mediating the second phase of response in the formalin test in the 7-day old rat pups. An important fact is revealed which indicates that in the prenatally stressed rat pups of the same age the second phase of response is already obvious. Mechanisms underlying the behavioral response caused by the inflammatory focus in the formalin test in the one-week old stressed rat pups are characterized by sexual dimorphism: the pain sensitivity in males at the second phase of response is statistically significantly higher than in females. 相似文献
15.
Martin S Angst Martha Tingle Nicholas G Phillips Brendan Carvalho 《Journal of visualized experiments : JoVE》2009,(23)
In a previous article in the Journal of Visualized Experiments we have demonstrated skin microdialysis techniques for the collection of tissue-specific nociceptive and inflammatory biochemicals in humans. In this article we will show pain-testing paradigms that are often used in tandem with microdialysis procedures. Combining pain tests with microdialysis provides the critical link between behavioral and biochemical data that allows identifying key biochemicals responsible for generating and propagating pain.Two models of evoking pain in inflamed skin of human study participants are shown. The first model evokes pain with aid of heat stimuli. Heat evoked pain as described here is predominantly mediated by small, non-myelinated peripheral nociceptive nerve fibers (C-fibers). The second model evokes pain via punctuated pressure stimuli. Punctuated pressure evoked pain is predominantly mediated by small, myelinated peripheral nociceptive nerve fibers (A-delta fibers). The two models are mechanistically distinct and independently examine nociceptive processing by the two major peripheral nerve fiber populations involved in pain signaling.Heat pain is evoked with aid of the TSA II, a commercially available thermo-sensory analyzer (Medoc Advanced Medical Systems, Durham, NC). Stimulus configuration and delivery is handled with aid of specific software. Thermodes vary in size and shape but in principle consist of a metal plate that can be heated or cooled at various rates and for different periods of time. Algorithms assessing heat-evoked pain are manifold. In the experiments shown here, study participants are asked to indicate at what point they start experiencing pain while the thermode in contact with skin is heated at a predetermined rate starting at a temperature that does not evoke pain. The thermode temperature at which a subject starts experiencing pain constitutes the heat pain threshold.Mechanical pain is evoked with punctuated probes. Such probes are commercially available from several manufacturers (von Frey hairs). However, the accuracy of von Frey hairs has been criticized and many investigators use custom made punctuated pressure probes. In the experiments shown here eight custom-made punctuated probes of different weights are applied in consecutive order, a procedure called up-down algorithm, to identify perceptional deflection points, i.e., a change from feeling no pain to feeling pain or vice versa. The average weight causing a perceptional deflection constitutes the mechanical pain threshold. 相似文献
16.
《Electromagnetic biology and medicine》2013,32(4):471-483
Spinal cord injury (SCI) is unequivocally reported to produce hyperalgesia to phasic stimuli, while both hyper- and hypoalgesia to tonic stimuli. The former is spinally mediated and the latter centrally. Besides, its management is unsatisfactory. We report the effect of magnetic field (MF; 17.96 μT, 50 Hz) on tonic pain behavior and related neurotransmitters in the brain of complete thoracic (T13) SCI rats at week 8. Adult male Wistar rats were divided into Sham, SCI and SCI+MF groups. Formalin-pain behavior was compared utilizing 5 min block pain rating (PR), 60 min session-PR, time spent in various categories of increasing pain (T0–T3) and flinch incidences. Serotonin (5-HT), dopamine (DA), norepinepherine (NE), gamma-aminobutyric acid (GABA), glutamate and glycine were estimated in brain tissue by liquid chromatography–mass spectrometry. Session-PR, block-PR and number of flinches were significantly lower, while time spent in categories 0–1 was higher in the SCI versus Sham group. These parameters were comparable in the SCI+MF versus Sham group. 5-HT concentration in cortex, remaining forebrain areas and brain stem (BS), was lower while GABA and NE were higher in BS of SCI, which were comparable with Sham in the SCI+MF group. The concentration of DA, glutamate and glycine was comparable amongst the groups. The data indicate significant hypoalgesia in formalin pain while increased in GABA, NE and decreased in 5-HT post-SCI, which were restored in the SCI+MF group. We suggest beneficial effect of chronic (2 h/day × 8 weeks) exposure to MF (50 Hz, 17.96 μT) on tonic pain that is mediated by 5-HT, GABA and NE in complete SCI rats. 相似文献
17.
Activation of “silent” efferent fibers due to stimulation of the mesenteric nerve within a definite frequency range is described;
the effect is supposed to result from sensitization in reflex circles related to visceral pain.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 4, pp. 368–369, July–August, 2006. 相似文献
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采取人工控制实验,探讨了6种C3、C4草本植物在昼/夜温度指标为20/12℃!36/28℃的范围内植物碳同位素组成(δ13C)及其对温度变化的响应,并结合植物比叶面积(SLA)、胞间CO2浓度(ci)与环境CO2浓度(ca)的比值、碳同化率(净光合速率Pn/胞间CO2浓度ci)等光合生长指标对植物δ13C的影响进行了分析。结果表明:所有C3、C4植物样品的δ13C值分别变化在-28.3‰!-32.1‰和-14.4‰!-17.6‰之间;在C3植物中,油菜δ13C值分布范围最集中,位于-31.1‰!-32.1‰之间;C4植物中,谷子δ13C值分布范围最窄。在控制的温度范围内,3种C3植物的平均δ13C值随温度升高而显著变低,而C4植物δ13C平均值与温度呈先增大后减小的抛物型关系,但线性回归结果未达到显著水平(P0.05)。单个植物种的δ13C值对温度的响应不同,茄子、高粱的δ13C值与温度呈线性负相关,其它4种植物与温度均呈二次抛物线关系,这可能与不同植物种具有不同的光合最适温度以及植物δ13C分馏对温度变化的敏感程度不同有关。 相似文献