General and Clinical Neurophysiology

Indisputable evidence that the effects of even small doses of radiation, with no acute radiation sickness, is unsafe for humans has accumulated in the years following the Chernobyl nuclear power station (CNPS) accident [12, 15, 16, 29]. Studies reported by a number of authors [2, 3, 12, 15, 16, 29] have shown that 3-4 years after exposure, CNPS clean-up workers developed persistent health impairments affecting various body systems-the cardiovascular, endocrine, immune , central nervous, and others, though these did not reach the level of forming a defined syndrome. This, along with the lack of experience in the diagnosis of post-radiation impairments, quite often led to denial of a relationship between deterioration in the state of health of clean-up workers and their work at Chernobyl. Application of contemporary clinical diagnostic methods have not only demonstrated this connection, but has also provided evidence for increases in impairments over time, which has been confirmed by results from neurophysiological studies [15, 28, 36]. Studies of the mechanism of post-radiation actions on the human body place a great emphasis on functional impairments to the vascular system, including the brain

Background: Overall, there is growing consensus that working memory (WM) should be routinely assessed in individuals with aphasia as it can contribute significantly to their level of language impairment and be an important factor in treatment planning. However, there is still no consensus in the field as to which tasks should be used to assess WM in aphasia. The two main alternatives are adapted complex span tasks and N-back tasks. Both have been used interchangeably in previous studies of WM in aphasia, even though the correspondence between the two tasks has not been properly established. Aims: The current study investigates the relationship between two WM tasks-complex span and N-back tasks-in a large sample of individuals with aphasia. The relationships of these tasks to measures of language comprehension are also explored, as well as differences in performance patterns between individuals with nonfluent and fluent aphasia. Methods & Resources: Forty-four participants with aphasia (nonfluent: n = 27; fluent: n = 13; mixed: n = 4) were examined with a modified listening span task (Ivanova & Hallowell, 2014), an auditory verbal 2-back task, and a standardised Russian language comprehension test. Outcomes & Results: Results revealed a moderate relationship between the two WM measures, but demonstrated a divergence in terms of their relationship to language comprehension. Performance on the modified listening span task was related to language comprehension abilities, but performance on the 2-back task was not, suggesting that the two tasks primarily index different underlying cognitive mechanisms. Furthermore, the relationship between the modified listening span task and language comprehension was significant for individuals with non-fluent aphasia, but not for those with fluent aphasia. Conclusions: Overall, the data demonstrate that while performance of individuals with aphasia was related on the two tasks, the two tasks cannot be substituted for one another without further inquiries into their underlying differences.

Background: Mild traumatic brain injury (mTBI) is one of the most common forms of cerebral pathology in young people and disorders involve dysfunctions in cognitive and motor spheres. We would like to examine the structural and functional alterations of the brain in patients with mTBI while performing hand movements. Methods: Twenty healthy right-handed subjects (age 25.1 ± 3.9) and 10 patients (age 27.9 ± 7.3) with mTBI without hemiparesis participated in the study using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). FMRI and EEG reactions were analysed during right-and left-hand movements. Results: It was shown that fMRI reactive changes have a larger inter-individual variability of activation during left-hand movements in comparison with right-hand ones in healthy subjects. The TBI patients demonstrated an increase of a diffuse component of fMRI reactive changes compared to healthy people. A greater number of the brain structures was involved, mainly at the subcortical level, mostly in the left hemisphere during right-hand movement. EEG study demonstrated coherence changes for the slow (delta) frequency bands in the left hemisphere, while performing both hand movements. In healthy persons, EEG coherence changes were observed in the fast (alhpa2) frequency band predominantly in contralateral hemispheres, while performing hand movements. Conclusion: So, fMRI and EEG studies revealed the most expressed pathological reactive changes in the left hemisphere and the brain cortical structures during right-hand movements in patients after mTBI. These data allowed us to propose that the younger brain structures were the most sensitive to mTBI.

volunteers were exposed to 5-minute action of controlled breathing. CBIFF frequency was equal to the frequency of maximum power peak localization in the low frequency range of heart rate spectrum. Members of the CBIFF group were instructed to change their breath rate following the image of inflating and deflating balloon appearing on the screen. Results: 50-day CBIFF course has led to changes in HRV of CBIFF group volunteers. The stress index (Si) has decreased by 29,3% (рb0,05), total power (TP), of heart rate has increased by 22,94% (рb0,05), HF power (ms 2) has increased by 35%, LF power-by12,94% (рb0,05). It indicates changes in volunteers' HRV associated with increase of vagal influences on heart rate. Moreover, CBIFF led to decrease in stress level and impacts of negative external factors on heart rate control system. Conclusion: Preliminary results of this study indicate a significant effect of CBIFF on volunteers' autonomic nervous system. CBIFF exposure reduces stress level and increases general nonspecific resistance of human organism. CBIFF can be recommended for increasing human stress resistance.

Introduction: It has been reported that a feeling of strangeness reflects that something is not right and could be related to an inconsistency between stimuli (Kawabata, 2006). This feeling causes stimuli to be observed and analyzed in more detail (Uchino et al., 2005). In this study, we investigated the cognitive processing of a strange feeling in a familiar face matching task by using eventrelated potentials (N2, P300 and N400). Method: University students (N = 20, 10 women and 10 men, mean age 21.7 ± 0.79 years) participated in this study. Participants judged and indicated whether two face pictures matched or not (S1 and S2) by a pressing a key. We measured the number of correct responses, reaction times (RTs) and the EEG during this task. The S2 pictures were classified by the degree of inconsistency and the feeling of strangeness, which were significantly and positively correlated (r = .99). Five conditions were tested; Match condition (S2 is consistent with S1), Mismatch-1 (mismatch-rate between S1 and S2 is 14.3 ± 4.9 %), Mismatch-2 (40.0 ± 6.5 %), Mismatch-3 (59.3 ± 11.0 %), and Mismatch-4 (82.9 ± 8.0%). S2 pictures were presented in a pseudorandom order. Result: Results indicated that the correct response rate increased in the larger mismatch-rate conditions. RTs in Mismatch-2 condition was slower than in Match, Mismatch-1, 3 and 4 conditions. Moreover, the correct response rates and RTs increased in Mismatch-2 than in Mismatch-1 (ps b .001). Furthermore, the P300 amplitude for S2 increased in Mismatch-1 than in Mismatch-2 (p b .05). On the other hand, N2 and N400 amplitudes increased in Mismatch-2 than in Mismatch-1 condition (ps b .001). Discussion: These suggested that the feeling of strangeness was induced in Mismatch-2 condition. The P300 and N2/N400 components might respectively reflect the ease of making a judgement and detecting inconsistencies, or the strange feeling between stimuli. However, it is not clear whether N2/N400 components reflected a feeling of strangeness or simply reflected the inconsistency between stimuli because the stimuli used in this study were positively correlated with inconsistency and strangeness. Future studies need to reinvestigate cognitive processing of the feeling of strangeness by using of stimuli that are negatively correlated with inconsistency and strangeness.