[Statistically significant reproducible differences of pericranial muscles EMG in beta and gamma frequency ranges when different emotional and cognitive states are compared].

Results of comparison of power of EMG of six pericranial muscles in electroencephalographic frequency ranges beta1, beta2 and gamma are presented corresponding to performances of the tasks bound to inductions of affective experiences-external by means of presentation of images and internal by means of autobiographical memoirs revived. The tasks were focused on an induction of affective experiences with different emotional valencies--positive, negative and neutral. The EMG was derived, registered and processed by means of a computer electroencephalography techniques. Self-ratings of signs and intensities of tested emotions were recorded as well. The study involved two groups of healthy subjects--students-actors (N = 39), and students of other majors (N = 32). Statistically reliable, reproducible and diverse differences of averaged EMG power of the pericranial muscles took place as in comparisons of psychophysiological conditions with different valencies of emotions, as well in comparisons of conditions without expressed emotional differences, but differing in the direction of attention. Therefore it is obviously necessary for an assessment of a degree of muscular contamination in records of high-frequency scalp EEG to supplement psychophysiological EEG methods with EMG registration and statistical analysis and to do such registration for several facial muscles.

[Event-related brain potentials when Russian verbs being conjugated: to the problem of language processing modularity].

In the light of alternative conceptions of "two-system" and "single-system" models of language processing the efforts have been undertaken to study brain mechanisnis for generation of regular and irregular forms of Russian verbs. The 19 EEG channels of evoked activity were registered along with casual alternations of speech morphology operations to be compared. Verbs of imperfective aspect in the form of an infinitive, belonging either to a group of productive verbs (default, conventionally regular class), or toan unproductive group of verbs (conventionally irregular class) were presented to healthy subjects. The subjects were requested to produce first person present time forms of these verbs. Results of analysis of event related potentials (ERP) for a group of 22 persons are presented. Statistically reliable ERP amplitude distinctions between the verb groups are found onlyin the latencies 600-850 ms in central and parietal zones of the cortex. In these latencies ERP values associated with a presentation of irregular verbs are negative in relation to ERP values associated with the presentation of regular verbs. The received results are interpreted as a consequence of various complexity of mental work with verbs of these different groups and presumably don't support a hypothesis of universality of the "two-system" brain mechanism for processing of the regular and irregular language forms.

[Induction of emotional states during oral reading of texts with different emotional valence and EEG power dynamics in frequency bands beta2 and gamma].

EEG power in frequency bands beta2 (18.5-29.5 Hz) and low gamma (30-40 Hz) was compared for situations while reading aloud with the technique "self-regulative utterance" texts as follow: a text with neutral emotional-semantic dominant; literary texts with either a positive or a negative emotional-semantic dominant; personal texts--recollections with similar dominants. Two groups of healthy subjects participated--a group of actor students (N=22) and a group of non-actor students (N=23). EEG power values in the states of emotiogenic texts reading are reproducibly differed with statistical significance from those in the state of reading ofa non-emotiogenic text. States of reading emotionally-positive texts are characterized by increases of EEG power in these bands, while those for emotionally negative texts--by decreases if compared with the state of emotionally neutral reading.

Green tea consumption, abdominal obesity as related factors of lacunar infarction in Korean women.

OBJECTIVES: Our purpose was to evaluate interaction of green tea consumption and abdominal obesity as related factors for lacunar infarction in Korean women. DESIGN: A hospital-based, incident case-control study. SETTINGS: The Prevention and Managements of Stroke in Women study. PARTICIPANTS: Cases (n=233) of first incident lacunar infarction were enrolled and matched by age to stroke-free hospital controls (n=204). MEASUREMENTS: The data were collected through face-to-face interviews by well trained research assistants to assess demographic, medical, lifestyle, marital status, religions status, green tea consumptions, family history of stroke, smoking status, alcohol consumption, meat and vegetable intake frequency, and past history of hypertension. Biochemical analysis, fasting blood specimens for lipid, glucose, and cholesterol level were acquired. RESULTS: Compared with the non green tea consumer and obese women group, only the green tea consumption and non obese women group had a protective effect of lacunar infarction when adjusted for age, and age plus diet factors (OR, 0.23; 95% CI, 0.09, 0.59; OR, 0.21; 95% CI, 0.08, 0.56 respectively), but lost their significance after adjustment for age, diet factors, vascular risk factors and full model included atherogenic index factors (OR, 0.32; 95% CI, 0.09 to 1.01; OR, 0.49; 95% CI, 0.12, 1.89 respectively). CONCLUSIONS: The interaction of green tea consumption and non obesity have reduced risk of lacunar infarction, but not after adjustment for age, diet factors, vascular risk factors and atherogenic index. Also individually green tea consumption and abdominal obesity have failed to find an independent relationship with lacunar infarction after adjustment by all risk factors. Green tea consumption and green tea consumption with non obese group seemed to have a protective effect for lacunar infarction. In the results of our study, these results still remain controversial, and then we need further and larger study to get at the root of real causal effect of both relationships.

[EEG changes with unblocking of acoustic and visual sensory canals].

Modally specific and supramodal components of EEG dynamics, related to involuntary reorientation of anticipatory attention from internal into external, were studied using unblocking of either visual or acoustic apparatus. EEG registration took place while the examinees were in the resting states: with opened eyes; with closed eyes; with closed eyes and inserted noise-protective earplugs. Averaged values of EEG power in each of the derivations and of EEG coherence in each of the derivation pairs were calculated for an every examinee and for each of the states. The estimations were done in delta, theta, alphal, alpha2, beta1, beta2, gamma frequency bands. The received results support an idea about manifestation of both supramodal and modally specific components in brain mechanisms of involuntary anticipatory attention. These results seem to be of certain interest for existing discussion on divergence and convergence between systemic mechanisms of visual and auditory attention.

[Effects of unstructured video exposure on EEG power in situations of forced attention and rest].

Group 1 (N = 30) and group 2 (N = 22) of healthy volunteers participated in the experiment. EEG registration took place while the examinees were in the resting states: with closed eyes; with opened eyes; with opened eyes and being under exposure to TV channel noises (white noise). Group 1 had also to fulfill a task to count randomly appearing symbols on a screen and group 2 had to fulfill a task to find an image in the noises. Averaged values of EEG power in each of the derivations in each of the derivations were calculated for an every examinee and for each of the states. The estimations were done in delta, theta, alpha1, alpha2, beta1, beta2, gamma frequency bands. The received results demonstrate that exposure to unstructured non-informative video noise can lead to significant changes of EEG power in a variety of frequency bands which are most prominent in the band alpha2. The changes are topically widespread, reflecting systemic changes in corresponding brain mechanisms, but are much less intensive if compared to changes between resting states with opened and closed eyes.

[EEG changes in comparison of rest states with open and closed eyes in complete darkness].

There are visible changes in EEG in transition from an awake resting state with eyes closed (REC) to an awake resting state with eyes opened (REO). These changes are usually treated as reflexion of brain activity reorganization in reply to visual perception. In present investigation we examined EEG records in awake resting states with opened and closed eyes in complete darkness. 30 healthy volunteers participated in this investigation. EEG (1.5-50 Hz) were recorded according to standard methods from 19 zones. EEG spectral power and coherence analysis demonstrates that REC and REO states differ even if the comparison corresponds to a situation of complete darkness. The differences are significant in any of the frequency ranges delta, theta, alpha1, alpha2, beta1, beta2, gamma. As compared states REC and REO don't differ neither by external visual information nor by illumination level therefore we presumably consider observed EEG changes as correlated with involuntary shift of anticipatory attention from interoceptive state with eyes closed to exteroceptive state with eyes opened.

[Electroencephalographic characteristic of cognitive-specific alerting attention in verbal learning--III: Localized characteristics of EEG spatial synchronization].

Electroencephalograms (EEG) were recorder in 19 standard derivations in 88 healthy subjects, while they were in the states: rest with eyes open; memorization (learning) of verbal bilingual semantic pairs (Latin and Russian languages); the retrieval of the rote information from memory (control). We compared estimates of EEG coherence in these states for the frequency bands theta (4-7 Hz), alpha-1 (7-10 Hz), alpha-2 (10-13 Hz), beta-1 (13-18 Hz), beta-2 (18-30 Hz), gamma (30-40 Hz). When compared with the rest most strongly expressed: for memorization a decrease of coherence in the pairs of derivations from frontal and central areas of the cortex in the EEG frequency bands; for retrieval an increase of coherence in interhemispheric derivation pairs of pariental-occipital region in majority of the frequency bands. For the retrieval also increases of coherence in the beta2 and gamma bands, along with coherence decreases at low frequencies take place in pairs formed by derivations from the parieto-occipital region with derivations from the frontal and the central ones. Dynamics of EEG coherence in comparisons of memorization and retrieval from the rest and each are expressed significantly more in the interhemispheric and crosshemispheric pairs of derivations than in the intrahemispheric pairs. Revealed topographic specificity of the dynamics of EEG coherence by changing the states is considered in terms of ideas about cognitive-specific forms of sustained goal-directed mental attention.

Preparation of biopolymer-coated magnetite nanoparticles for magnetic resonance image contrast agent.

The magnetite nanoparticles were synthesized using the sonochemical method with oleic acid as surfactant. The average size of the magnetite particles can be controlled by the ratio R = [H2O]/[surfactant] in the range of 2 to 9 nm. The size of the magnetite nanoparticles prepared by this method shows the narrow distribution. To prepare biopolymer(beta-glucan)-coated magnetite nanoparticles, beta-glucan solution was added to the magnetic colloid suspensions under the ultrasonication at room temperature. The beta-glucan coated magnetite colloidal suspensions of various concentrations did not agglomerate for 15 days, indicating their good stability. The beta-glucan-coated magnetite colloidal suspensions exhibited the enhancement of MRI contrasts in vitro.