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1.
To justify neurophysiological correlates of depressive disorders, the spetral parameters of EEG, peak latencies of the “late”
components of auditory cognitive evoked potentials, and latencies of sensorimotor reactions in middle age and elderly patients
(aged 53–72 years) during therapy of prolonged psychogenic depressive reaction (F43.21 according to ICD-10) have been studied.
Initial depression severity was associated to the EEG signs of decreased functional state of the anterior areas of the left
hemisphere and increased activation of the right hemisphere (especially, its temporal areas). Pronounced improvement of clinical
state under the affect of psychopharmacotherapy was accompanied by acceleration of the sensorimotor reactions, a decrease
in peak latencies of the “late” components (P2, N2, and P3) of auditory cognitive evoked potentials and associated with the EEG signs of improvement of functional state of the posterior
areas of the brain, an enforcement of inhibitory processes in the right hemisphere (especially, in its frontal, central, and
temporal areas) and more pronounced activation of frontal areas of the left hemisphere. The data are in good agreement with
the concept on the systemic character of impairments of brain functioning in depression, as well as on the preferential role
of the left hemisphere in control of positive emotions and the right one, of negative emotions. 相似文献
2.
Reflection of Anxiety in the Characteristics of Evoked EEG Potentials in 10- to 11-Year-Old Children
We studied the peculiarities of the amplitude/time parameters of evoked EEG potentials (EPs) and event-related potentials
(ERPs) in 10- to 11-year-old children characterized by low and high anxiety levels. The latter levels were estimated using
the scale of the manifest anxiety test of Prikhozhan and projective techniques (“House–Tree–Person,” HTP, and the Lüscher
color test). For children with a high anxiety level, the amplitudes of the following EP components and ERPs were lower than
those in low-anxiety children of the same age: P1 (predominantly in the occipital region of the left hemisphere), P2 (in the
right occipital region), and Р300 wave (in different loci of both hemispheres). In high-anxiety children, we also more frequently
observed increased amplitudes of the N2 component in the left parietal and right occipital regions. High-anxiety individuals
were characterized by longer latencies of component P1 (mostly in the right frontal and left central regions) and, at the
same time, shorter latencies of component N1 (in the parietal and occipital regions of the left hemisphere and also in the
right temporal region). Thus, we found that the amplitude/time characteristics of a few EP components and ERPs in children
with high anxiety levels differ statistically significantly from the parameters of corresponding EPs/ERPs in individuals of
the same age but with low anxiety levels. 相似文献
3.
María Luisa García-Gomar Efraín Santiago-Rodríguez Mario Rodríguez-Camacho Thalía Harmony 《PloS one》2013,8(7)
Background
Periventricular Leukomalacia (PVL) affects white matter, but grey matter injuries have also been reported, particularly in the dorsomedial nucleus and the cortex. Both structures have been related to working memory (WM) processes. The aim of this study was to compare behavioral performances and EEG power spectra during a visuospatial working memory task (VSWMT) of toddlers with a history of PVL and healthy toddlers.Methodology/Principal Findings
A prospective, comparative study of WM was conducted in toddlers with a history of PVL and healthy toddlers. The task responses and the EEG narrow-band power spectra during a VSWMT were compared in both groups. The EEG absolute power was analyzed during the following three conditions: baseline, attention and WM retention. The number of correct responses was higher in the healthy group (20.5±5.0) compared to the PVL group (16.1±3.9) (p = 0.04). The healthy group had absolute power EEG increases (p≤0.05) during WM compared to the attention condition in the bilateral frontal and right temporal, parietal and occipital regions in frequencies ranging from 1.17 to 2.34 Hz and in the right temporal, parietal and occipital regions in frequencies ranging from 14.06 to 15.23 Hz. In contrast, the PVL group had absolute power increases (p≤0.05) in the bilateral fronto-parietal, left central and occipital regions in frequencies that ranged from 1.17 to 3.52 Hz and in the bilateral frontal and right temporal regions in frequencies ranging from 9.37 to 19.14 Hz.Conclusions/Significance
This study provides evidence that PVL toddlers have visuospatial WM deficits and a very different pattern of absolute power increases compared to a healthy group of toddlers, with greater absolute power in the low frequency range and widespread neuronal networks in the WM retention phase. 相似文献4.
We studied correlations between the frequency of background impulse activity (BIA) of dopaminergic (DAergic) neurons of the
ventral tegmentum (VT) and spectral power (SP) of the frequency components of EEG samples recorded in awake cats. The EEG
was recorded monopolarly (electrodes were fixed in the cranial bones) from the frontal, occipital, and right and left temporal
regions of the cortex. In a great majority of the cases, the BIA frequency of VT DA-ergic neurons demonstrated significant
positive correlations with changes in the SPs of the alpha and beta EEG rhythms. The closest correlations of the spiking frequency
of DA-ergic cells with the SP of the alpha rhythm was observed in the occipital region, while those with the beta SP were
found in the frontal area. Correlations of the activity of DA-ergic neurons with the SPs of the alpha and beta rhythms in
the left temporal cortical zone were closer, as compared with those in the symmetrical right zone. Correlations of the SPs
of the delta, theta, and gamma EEG components with the discharge frequency of VT DA neurons were of opposite directions, and
in most cases such correlations did not reach the level of significance. The results of this study show that, in some cases,
specific EEG patterns can be considered indicators of the state of the cerebral VT DA-ergic system.
Neirofiziologiya/Neurophysiology, Vol. 40, No. 4, pp. 359–367, July–August, 2008. 相似文献
5.
E. Ba?ar B. Güntekin ?. Atagün B. Turp G?lba?? E. Tülay A. ?zerdem 《Cognitive neurodynamics》2012,6(1):11-20
Brain’s alpha activity and alpha responses belong to major electrical signals that are related to sensory/cognitive signal
processing. The present study aims to analyze the spontaneous alpha activity and visual evoked alpha response in drug free
euthymic bipolar patients. Eighteen DSM-IV euthymic bipolar patients (bipolar I n = 15, bipolar II n = 3) and 18 healthy controls were enrolled in the study. Patients needed to be euthymic at least for 4 weeks and psychotrop
free for at least 2 weeks. Spontaneous EEG (4 min eyes closed, 4 min eyes open) and evoked alpha response upon application
of simple visual stimuli were analyzed. EEG was recorded at 30 positions. The digital FFT-based power spectrum analysis was
performed for spontaneous eyes closed and eyes open conditions and the response power spectrum was also analyzed for simple
visual stimuli. In the analysis of spontaneous EEG, the ANOVA on alpha responses revealed significant results for groups (F(1,34) = 8.703; P < 0.007). Post-hoc comparisons showed that spontaneous EEG alpha power of healthy subjects was significantly higher than
the spontaneous EEG alpha power of euthymic patients. Furthermore, visual evoked alpha power of healthy subjects was significantly
higher than visual evoked alpha power of euthymic patients (F(1,34) = 4.981; P < 0.04). Decreased alpha activity in spontaneous EEG is an important pathological EEG finding in euthymic bipolar patients.
Together with an evident decrease in evoked alpha responses, the findings may lead to a new pathway in search of biological
correlates of cognitive impairment in bipolar disorder. 相似文献
6.
Coherence at the frequency of θ, α, and β EEG rhythms was analyzed in 14 adults and 23 children of 7–8 years old while they
performed cognitive tasks requiring an involvement of working memory (WM). We used the pair matching paradigm in which subjects
had to match a pair of stimuli shown in succession in the central visual field. The pairs of verbal and visuo-spatial stimuli
were mixed together and presented in a pseudo random order. Each pair was preceded by a warning signal that did not specify
a modality of upcoming stimuli. We analyzed EEG segments recorded (i) in the rest condition, (ii) prior to the first (reference)
stimulus (maintenance of nonspecific voluntary attention), and (iii) prior to the second (test) stimulus (retention of information
in WM). In the present study we focused on the regulatory functional components of WM, and therefore, the stimulus modality
has not been taken into account. In adults, maintaining nonspecific voluntary attention was accompanied by an increase of
the strength of θ-related functional coupling between medial areas of the frontal cortex and temporal cortical zones and by
a strengthening of local β-related functional connectivity in the fronto-central areas of the cortex. In children, no such
increase was found for θ rhythm; for β rhythm the increase was limited to several short-range functional links. In adults,
the retention of information in WM was accompanied by the growth in α coherence in distant fronto-parietal links, predominantly
in the right hemisphere, while in children information retention was accompanied by the growth of θ coherence in the inferio-temporal
and parietal cortical regions. The results of the study point to a relative immaturity of the mechanisms of executive control
of WM in children of 7–8 years old. 相似文献
7.
The development of the resonance EEG responses of the left and right occipital areas was studied in right-handed men during
prolonged (12 or 120 s) rhythmic, photostimulation with the intensity of 0.7 J and frequencies of 6, 10, and 16 Hz. Analysis
of the EEG fine spectral structure was applied to compare the accumulated baseline EEG spectra and EEG spectra during photostimulation,
to observe the dynamics of the short-term spectra and to detect power changes in the EEG narrow spectral band sharply coincident
with the stimulation frequency. The more pronounced EEG responses to photostimulation were observed in subjects with the initially
low EEG baseline, α-rhythm. Two-minute flash trains produced a substantial increase in the EEG power within the stimulation
frequency with superposed oscillatory processes with different periods. These fluctuations are considered a reflection of
intricate interaction between the adaptive and resonance EEG responses to the presented intermittent stimulation. Under 12-s
stimulation the resonance EEG responses are steadily recorded within the first 3 s of stimulation and immediately after the
flash cessation EEG power at the stimulation frequency returns to the initial level. The resonance EEG responses were more
pronounced in the right hemisphere than in the left one, especially, at the stimulation frequencies of 6 and 16 Hz. With increasing
the stimulation frequency, the maximum of resonance EEG responses was reached earlier. Under the stimulation frequency of
6 Hz, the maximal response was recorded 9–12 s after the beginning of flashes, at the frequencies of 10 and 16 Hz, it was
recorded within 3–6 and 3 s, respectively. 相似文献
8.
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
9.
Sokhadze EM 《Applied psychophysiology and biofeedback》2007,32(1):31-50
The purpose of this study was to compare the effects of music and white noise on the recovery of physiological measures after
stressful visual stimulation. Twenty-nine participants took part in the experiment. Visual stimulation with slides eliciting
disgust was followed by subjectively pleasant music, sad music, and white noise in three consecutive sessions. The spectral
power of the frontal and temporal EEG, skin conductance, heart rate, heart period variability, facial capillary blood flow,
and respiration rate were recorded and analyzed. Aversive visual stimulation evoked heart rate deceleration, increased high
frequency component of heart period variability, increased skin conductance level and skin conductance response frequency,
decreased facial blood flow and velocity, decreased temporal slow alpha and increased frontal fast beta power in all three
sessions. Both subjectively pleasant and sad music led to the restoration of baseline levels on most parameters; while white
noise did not enhance the recovery process. The effects of pleasant music on post-stress recovery, when compared to white
noise, were significantly different on heart rate, respiration rate, and peripheral blood flow. Both positive and negative
music exerted positive modulatory effects on cardiovascular and respiratory activity, namely increased heart rate, balanced
heart period variability, increased vascular blood flow and respiration rate during the post-stress recovery. Data only partially
supported the “undoing” hypothesis, which states that positive emotions may facilitate the process of physiological recovery
following negative emotions. 相似文献
10.
Razumnikova OM Vol'f NV Tarasova IV 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2007,57(5):553-561
Effect of extrinsic motivation stimulating the most original problem solving during verbal and figurative divergent thinking was studied by EEG mapping. The righthanded university students (27 males and 26 females) participated in the experiments. An instruction "to create the most original solution" as compared to condition with an instruction "to create any solution" induced an increase in the baseline power of the alpha 1 and alpha 2 rhythms most pronounced in the posterior cortex. Task-related desynchronization of the alpha rhythms was higher but the beta-2 synchronization was lower after the former than after the latter instruction. Differences in the asymmetry of the alpha 1 and alpha 2 rhythms in the parietal and temporal regions of hemispheres suggested the right hemisphere dominance in intrinsic alertness and evoked activation related to divergent thinking. The findings were common and gender-independent in both figurative and verbal tasks suggesting a generalized influence of extrinsic motivation on creative activity. 相似文献
11.
We studied peculiarities of the spectral characteristics of EEG in 111 healthy adult subjects of both sexes. The levels of
situative anxiety (anxiety state) and personal anxiety were estimated using the Spielberger–Khanin test system. To estimate
anxiety-related properties of the personality, Cattel’s technique 16 PF (form А) was used. Estimates of situative anxiety
demonstrated only two cases of positive correlation with the spectral power density (SPD) of EEG rhythms (SPDs of the beta2
rhythm in the right-hemisphere temporal and occipital regions; recording with the eyes open). Estimates of personal anxiety
positively correlated with the SPDs of the beta1 and (especially) beta2 EEG rhythms. Under conditions with the eyes open,
the number of significant correlations was greater, and correlations themselves were tighter than with the eyes closed. The
closest correlations of the estimates of personal anxiety with the SPDs of the beta rhythm were found in frontal and central
leads of both hemispheres and in parietal and occipital loci of the right hemisphere. Only a single case of correlation of
the alpha rhythm SPD with personal anxiety (negative correlation, a parietal lead in the left hemisphere) was found. At the
same time, rather numerous correlations of the alpha rhythm expression with an index congeneric to anxiety, the C factor by
the Cattel’s questionnaire (emotional stability/instability), were found. Thus, the intense beta EEG rhythm can be considered
an electrographic correlate of high situative and personal anxieties. At the same time, the alpha rhythm power correlates
with the emotional stability of the individual. We suppose that persons with a well-developed alpha rhythm are characterized
by active and stable functioning of the cerebral dopaminergic system; this simultaneously serves as a pre-requisite of high
emotional stability and social adaptability. 相似文献
12.
E. I. Batukhtina T. I. Nevidimova T. P. Vetlugina N. P. Kokorina N. A. Bokhan 《Human physiology》2013,39(4):386-391
Electroencephalographic (EEG) spectra have been analyzed under baseline conditions and during olfactory stimulation in substance-dependent and healthy subjects. The intergroup differences in the EEG spectra resulting from an increase in the power of cortical bioelectric potentials in patients with disorders due to psychoactive substance use were recorded in the parietal and temporal EEG leads. Interhemispheric differences have been found in the contribution of different frequencies to the spectral characteristics of the EEG. In patients with addictive disorders, in the temporal area of the left hemisphere, in the high-frequency range, a significant increase in the power of bioelectric potentials was recorded under baseline conditions and during olfactory stimulation. An increased power of α activity was typical of the temporal area of the right hemisphere in patients with disorders due to psychoactive substance use compared to the healthy subjects. The neurophysiological patterns found may be related to the psychological and behavioral features of addictive disorders. 相似文献
13.
Clara Moisello Hadj Boumediene Meziane Simon Kelly Bernardo Perfetti Svetlana Kvint Nicholas Voutsinas Daniella Blanco Angelo Quartarone Giulio Tononi Maria Felice Ghilardi 《PloS one》2013,8(6)
Recent EEG studies have shown that implicit learning involving specific cortical circuits results in an enduring local trace manifested as local changes in spectral power. Here we used a well characterized visual sequence learning task and high density-(hd-)EEG recording to determine whether also declarative learning leaves a post-task, local change in the resting state oscillatory activity in the areas involved in the learning process. Thus, we recorded hd-EEG in normal subjects before, during and after the acquisition of the order of a fixed spatial target sequence (VSEQ) and during the presentation of targets in random order (VRAN). We first determined the temporal evolution of spectral changes during VSEQ and compared it to VRAN. We found significant differences in the alpha and theta bands in three main scalp regions, a right occipito-parietal (ROP), an anterior-frontal (AFr), and a right frontal (RFr) area. The changes in frontal theta power during VSEQ were positively correlated with the learning rate. Further, post-learning EEG recordings during resting state revealed a significant increase in alpha power in ROP relative to a pre-learning baseline. We conclude that declarative learning is associated with alpha and theta changes in frontal and posterior regions that occur during the task, and with an increase of alpha power in the occipito-parietal region after the task. These post-task changes may represent a trace of learning and a hallmark of use-dependent plasticity. 相似文献
14.
Gordeev SA 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2007,57(3):282-291
Brain electrical activity was recorded in 38 patients with typical and in 42 patients with atypical panic disorders, also in 30 normal controls. Compared to controls, patients both with typical and with atypical panic disorders differed significantly in reduced spectral power of the EEG alpha band in the right hemisphere. Moreover, in patients with typical panic disorders, the spectral power of the EEG beta1 band was increased in the frontal, temporal, central, and parietal areas of the right hemisphere. In patients with atypical panic disorders, the spectral power of the theta band was increased in the temporal areas of the right hemisphere. The changes in the EEG activity in patients with typical panic disorders are supposed to reflect an increase in activity of non-specific systems of the mesencephalic reticular formation, and the EEG changes in patients with atypical panic attacks may be associated with increased activity of the temporolimbic brain structures. 相似文献
15.
Inferring the intentions of other people from their actions recruits an inferior fronto-parietal action observation network as well as a putative social network that includes the posterior superior temporal sulcus (STS). However, the functional dynamics within and among these networks remains unclear. Here we used functional magnetic resonance imaging (fMRI) and high-density electroencephalogram (EEG), with a repetition suppression design, to assess the spatio-temporal dynamics of decoding intentions. Suppression of fMRI activity to the repetition of the same intention was observed in inferior frontal lobe, anterior intraparietal sulcus (aIPS), and right STS. EEG global field power was reduced with repeated intentions at an early (starting at 60 ms) and a later (∼330 ms) period after the onset of a hand-on-object encounter. Source localization during these two intervals involved right STS and aIPS regions highly consistent with RS effects observed with fMRI. These results reveal the dynamic involvement of temporal and parietal networks at multiple stages during the intention decoding and without a strict segregation of intention decoding between these networks. 相似文献
16.
V. A. Ponomarev O. E. Gurskaya Yu. D. Kropotov L. V. Artjushkova A. Müller 《Human physiology》2010,36(2):123-131
The efficiencies of three clustering methods for independent components of 19-channel baseline EEG in location of pathological
cerebral activity sources were compared. The samples comprised 518 healthy subjects and 87 patients with postconcussion syndrome
after traumatic brain injury (TBI). Clustering of independent component topographies, the spatial coordinates of equivalent
dipole sources corresponding to independent component topographies, and locations of the maximums of the equivalent source
current density calculated by standardized low resolution electromagnetic tomography (sLORETA) were compared. A comparison
of the power spectra of independent components showed a significant increase in the EEG power in the Δ, θ, and α bands for
sources located in the frontal and temporal lobes of TBI patients compared to healthy subjects. The method of clustering of
independent component topographies proved to be the most sensitive of the methods compared. 相似文献
17.
We studied changes in the amplitudes of event-related EEG potentials (ERPs) and power spectra of background EEG in the course
of a series of EEG-feedback sessions directed toward an increase in the ratio of powers of the α vs θ rhythms. The examined group included 70 volunteers divided into an experimental group (n = 37) and a control group (n = 33). The intensity of acoustic white noise overlapping the musical background served as a feedback signal; it became lower
with increase in the above ratio, while in the control group it remained constant. The EEG potentials were recorded from C3
and C4 leads. The ERPs were recorded within a paradigm of measuring time intervals. Within a series of EEG-feedback sessions,
the α/θ ratio decreased somewhat both in the control and experimental groups, but in subjects of the latter group this decrease
was less significant, and the mean intragroup index became significantly greater than the respective value in the control
group after the end of the third session. The EEG-feedback sessions also resulted in significant increases in the amplitudes
of early components of the readiness potential in both hemispheres and in the amplitude of the contingent negative variation
in the right hemisphere. We conclude that, in most healthy subjects, at least three sessions of α/θ training are necessary
to form an effective series providing considerable changes in the pattern of EEG potentials.
Neirofiziologiya/Neurophysiology, Vol. 39, No. 1, pp. 88–98, January–February, 2007. 相似文献
18.
In awake cats trained to perform a food-procuring conditioned operant reflex (placing movement), we studied impulse reactions of 86 neurons of the motor cortex (field 4) related to realization of the above movements. As conditioning stimuli (CS) initiating the reflex, we used either non-noxious electrocutaneous stimulation (ECS) of the contralateral forelimb or an acoustic stimulus (sound click). Impulsation of cortical neurons was recorded under conditions of (i) isolated presentation of the CS (control), (ii) presentation of the CS (either ECS or acoustic stimulus) combined with thermostimulation (heating with a miniature electric bulb) of the skin of the working forelimb, and (iii) the same, but with stimulation of the resting forelimb. When we recorded spike activity of neurons within the projection motor zone of the resting limb subjected to ESC, alternating thermostimulation of both forelimbs resulted in considerable intensification and an increase in the duration of neuronal responses, especially in cases where thermostimulation was applied to the working limb ipsilateral to the recording site (a two- to threefold increase). When spike reactions were recorded within the motor cortex of the working forelimb, thermostimulation resulted in a considerable increase in the intensity of these reactions and a decrease in their latency, but only when such stimulation was applied to the working forelimb. Thermostimulation of the resting (ipsilateral, subjected to ESC) limb evoked opposite effects (the intensity of neuronal reactions dropped). In both situations, placing movements remained within the control limits. When sound click was used as a distant CS, thermostimulation of the working limb enhanced neuronal responses, increased their duration by 50-100%, and also increased the time of forestalling of the movement initiation by spike neuronal reactions. Thermostimulation of the resting forelimb in this situation also suppressed neuronal reactions. We conclude that foreign stimulations directed toward modifications of the receptor model of the operant reflex experimental situation formed in the animal result in a decrease in the intensity of the spike responses of field-4 neurons and prolongation of the latencies of these responses, while stimulations promoting the inflow of afferent information to the cortical projection of the working limb evoke opposite effects, an increase in the intensity of neuronal spike responses and a decrease in their latencies. 相似文献
19.
Topographic analysis of dimension estimates of EEG and filtered rhythms in epileptic patients with complex partial seizures 总被引:2,自引:0,他引:2
Nonlinear dynamic properties were analyzed on the EEG and filtered rhythms recorded from healthy subjects and epileptic patients
with complex partial seizures. Estimates of correlation dimensions of control EEG, interictal EEG and ictal EEG were calculated.
The values were demonstrated on topograms. The delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz) and gamma
(30–40 Hz) components were obtained and considered as signals from the cortex. Corresponding surrogate data was produced.
Firstly, the influence of sampling parameters on the calculation was tested. The dimension estimates of the signals from the
frontal, temporal, parietal and occipital regions were computed and compared with the results of surrogate data. In the control
subjects, the estimates between the EEG and surrogate data did not differ (P > 0.05). The interictal EEG from the frontal region and occipital region, as well as its theta component from the frontal
region, and temporal region, showed obviously low dimensions (P < 0.01). The ictal EEG exhibited significantly low-dimension estimates across the scalp. All filtered rhythms from the temporal
region yielded lower results than those of the surrogate data (P < 0.01). The dimension estimates of the EEG and filtered components markedly changed when the neurological state varied.
For each neurological state, the dimension estimates were not uniform among the EEG and frequency components. The signal with
a different frequency range and in a different neurological state showed a different dimension estimate. Furthermore, the
theta and alpha components demonstrated the same estimates not only within each neurological state, but also among the different
states. These results indicate that the theta and alpha components may be caused by similar dynamic processes. We conclude
that the brain function underlying the ictal EEG has a simple mechanism. Several heterogeneous dynamic systems play important
roles in the generation of EEG.
Received: 10 December 1999 / Accepted in revised form: 8 May 2000 相似文献
20.
Mathilde Chipaux Matthew T. Colonnese Audrey Mauguen Laure Fellous Mostafa Mokhtari Oscar Lezcano Mathieu Milh Olivier Dulac Catherine Chiron Rustem Khazipov Anna Kaminska 《PloS one》2013,8(11)
In the premature infant, somatosensory and visual stimuli trigger an immature electroencephalographic (EEG) pattern, “delta-brushes,” in the corresponding sensory cortical areas. Whether auditory stimuli evoke delta-brushes in the premature auditory cortex has not been reported. Here, responses to auditory stimuli were studied in 46 premature infants without neurologic risk aged 31 to 38 postmenstrual weeks (PMW) during routine EEG recording. Stimuli consisted of either low-volume technogenic “clicks” near the background noise level of the neonatal care unit, or a human voice at conversational sound level. Stimuli were administrated pseudo-randomly during quiet and active sleep. In another protocol, the cortical response to a composite stimulus (“click” and voice) was manually triggered during EEG hypoactive periods of quiet sleep. Cortical responses were analyzed by event detection, power frequency analysis and stimulus locked averaging. Before 34 PMW, both voice and “click” stimuli evoked cortical responses with similar frequency-power topographic characteristics, namely a temporal negative slow-wave and rapid oscillations similar to spontaneous delta-brushes. Responses to composite stimuli also showed a maximal frequency-power increase in temporal areas before 35 PMW. From 34 PMW the topography of responses in quiet sleep was different for “click” and voice stimuli: responses to “clicks” became diffuse but responses to voice remained limited to temporal areas. After the age of 35 PMW auditory evoked delta-brushes progressively disappeared and were replaced by a low amplitude response in the same location. Our data show that auditory stimuli mimicking ambient sounds efficiently evoke delta-brushes in temporal areas in the premature infant before 35 PMW. Along with findings in other sensory modalities (visual and somatosensory), these findings suggest that sensory driven delta-brushes represent a ubiquitous feature of the human sensory cortex during fetal stages and provide a potential test of functional cortical maturation during fetal development. 相似文献