EEG Cortical Activities and Networks Altered by Watching 2D/3D Virtual Reality Videos

Virtual reality (VR), which can represent real-life events and situations, is being increasingly applied to many fields, such as education, entertainment, and medical rehabilitation. Correspondingly, the neural information processing of VR has attracted attention. However, the underlying neural mechanisms of VR environments have not yet been fully revealed. The purpose of this study was to examine the possible differences in brain activities and networks between the less immersive 2D and the fully immersive 3D VR environments. 3D VR videos and the same 2D scenes were presented to the participants and the scalp electroencephalogram (EEG) was recorded, respectively. Power spectral density (PSD) and the functional connectivity of these EEG signals were analyzed. The results showed that 3D VR videos significantly enhanced the PSD of θ rhythm (4–7 Hz) in the frontal lobe; decreased the PSD of α rhythm (8–13 Hz) in the parietal and the occipital lobes; increased the PSD of β rhythm (14–30 Hz) in the frontal, the parietal, the temporal, and the occipital lobes, relative to 2D VR watching. Furthermore, 3D versus 2D VR-induced alterations in the patterns of brain networks were similar to the patterns of PSD. Specifically, for the θ rhythm, 3D VR significantly enhanced the frontal and the temporal brain functional connectivity; for the α rhythm, 3D VR increased the parietal and the occipital networks; for the β rhythm, 3D VR remarkably increased the frontal, the occipital, the frontal-temporal and the frontal-occipital brain functional connectivity, relative to 2D VR. These significant differences between 3D and 2D VR video-watching suggest that the neural information processing of cortical activities and networks is correlated to the degree of immersion. The present results, collected with previous researches, implicate that some visual-related information processes, such as visual attention, visual perception, and visual immersion are more robust in 3D VR environments.

EEG sensorimotor rhythms in children with autism spectrum disorders

One of the currently assumed causes of impaired social interaction exhibited by children with autism spectrum disorders (ASD) is dysfunction of the mirror neuron system (MNS), which is responsible for imitation, understanding the intentions and emotions of other people. Desynchronization of sensorimotor rhythms is considered to be the indicator of MNS activation. This study aimed to analyze the specific patterns of reactivity of the μ-rhythm in an individually determined frequency range and β-rhythm on the EEG in children with ASD during independent movements, observation, imitation and auditory perception of similar movements performed by another person. The data collected were compared to those describing normally developing children. The study involved right-handed children with ASD aged 5–10 (n = 10) and normally developing children (n = 10). In the independent movements exercise, β-rhythm desynchronization was more pronounced in children with ASD, with difference becoming significant in the P4 locus (p = 0.03). In the movements imitation exercise, the groups showed significant differences in the EEG μ-rhythm in the locus C3 (p = 0.03). Auditory perception of movements revealed significant differences in the ranges of both μ-rhythm (loci F3 and Fz (p = 0.02), F4 (p = 0.04), Cz (p = 0.009)) and β-rhythm (loci Fz (p = 0.01), F4 (p = 0.02)). In these situations, children with ASD exhibited synchronization of sensorimotor rhythms, while normally developing children showed desynchronization. The assumption is that the specific patterns revealed are the consequences of disruption of functions of MNS and anti-mirror system. The data obtained can be used in development of EEG biofeedback training protocols for children with ASD.

Similarity Of Effects On EEG And HRV Parameters Of Aramaic, Greek Catholic And Krishnaic Prayers

The object of observation were 4 men: Greek Catholic priest Father Volodymyr, head of the Church Brotherhood Ivan, a supporter of Krishna Victor, and your obedient servant, the first author to memorize the authentic Lord's Prayer in Aramaic. Results. The neurotropic effects of Prayer are manifested in two inhibitory and three activating patterns. The first inhibitory pattern reflects the decrease in elevated and upper limit levels of SPD of θ-and δ-rhythm in frontal loci and the second - decrease in normal SPD levels of β-and θ-rhythm in the frontal, central, temporal and parietal loci. The first activating pattern reflects a small increase in normal levels of β-rhythm index and asymmetry and SPD entropy in locus C3, as well as a further increase in elevated δ-rhythm SPD levels in loci P3 and T3. The second pattern reflects the slight increase in normal SPD levels of θ-rhythm in loci T3, T5, T6, O2 and α-rhythm in locus T5, as well as their indices and entropy SPD in locus O2. The third pattern reflects a slight increase in amplitude and SPD of α-rhythm in central, frontal, temporal and occipital loci.

EPISIOTOMY AS ONE OF THE PROBLEMS OF MODERN PERINIOLOGY

Objective: the study is to determine the effectiveness of EEG-biofeedback training on β-rhythm for correcting voluntary attention in children 6 – 8 years of age with the consequences of perinatal CNS lesions of hypoxic-ischemic genesis. Materials and methods: a total of 120 children aged 6 – 8 years who included 30 children with cerebrastenic syndrome (I group) were examined; 58 children with hyperactivity and attention deficit syndrome (II group); 32 children with cerebral palsy, spastic diplegia (III group). EEG-biofeedback training on β-rhythm correction was carried out in an amount of 15 sessions lasting 20 – 30 minutes on the Kinesis machine (Neurot, Russia). Before and after the biofeedback therapy, a psychodiagnostic evaluation of the functions of voluntary attention on the Toulouse-Pieron scale was carried out (in the adaptation of LA Yasyukova, 2001). EEG recording was performed on an EEG 21/26 encephalograph Encephalan-131-03, modification 10 (Manufacturer: NPKF Medikom MTD, Russia). For statistical analysis of the obtained indicators before and after treatment, the significance criterion was used to compare the two proportions (fractions) under the assumption that the variables are distributed according to the normal law (package STATISTICS 6.0). Results: the effectiveness of EEG-biofeedback training on β-rhythm correction was revealed, as evidenced by a significant decrease in the number of children with isolated types of attention disorders in all groups of patients as well as with mixed disorders in the II group. Conclusion: аctivation of cortical processes, increasing the level of attention, memory and cognitive abilities of the psyche, when EEG-biofeedback training is included in the therapy complex, depend on the nature and severity of central nervous system lesions in children with various nosological forms of neurological pathology, which requires rethinking of therapeutic complex methods of correction and selection of personalized biofeedback training protocols, taking into account data on various types of metabolic and neurophysiological abnormalities in the head in children with different nosological forms of neurological disorders.

THE PECULIARITIES OF THE HEART RATE VARIABILITY AND ELECTROENCEPHALOGRAM CHANGES IN PATIENTS WITH EPILEPSY AND CARDIOVASCULAR PATHOLOGY

Introduction: Epidemiological studies have shown that the risk of myocardial infarction and stroke is significantly higher in patients with epilepsy compared with people not suffering from epilepsy. The aim of the study was to study the parameters of HRV and EEG in patients with epilepsy to identify risk factors for cardiovascular pathology. Materials and methods: We observed 50 patients with epilepsy without cardiovascular pathology (group 1) and 56 patients with epilepsy and cardiovascular pathology (group 2). All patients underwent clinical neurological examination, EEG, HRV and ECG assessment. Results: There was a significant decrease in the HRV power in both groups of patients compared with general population data (p <0.02). Also in patients of the 2nd group, TP and the power of HRV in the LF, HF ranges were significantly decreased (p <0.001). Unstrained autonomic balance was detected in 40% in the 1st group and in 6% of patients in the 2nd group (p <0.001). Each patient had as higher LF/HF ratio as less time to next seizure left (rs = 0.72; p <0.05). There was no correlation of the heart rate (ECG) and the time to the next seizure (rs = 0.12; p <0.05). A correlation of the LF / HF ratio with β rhythm (EEG) was revealed for patients in both groups (for group 1: rs = 0.48; for group 2: rs = 0.52; p <0.02). When evaluating HRV in both groups, depending on the taken AEDs, it was found that the average values of TP, VLF, LF, HF, SDNN were significantly lower in patients receiving carbamazepine when compared with patients receiving other AEDs (p<0.001). Conclusions: The factors of increased cardiovascular risk were: tense autonomic balance with a tendency to sympathicotonia, signs of a decrease in parasympathetic activity, a decrease in the TP, an increase in the representation of the EEG β-rhythm. The magnitude of the change in the frequency of the α rhythm in response to hyperventilation as well as the magnitude of the change in TP in orthostasis can serve as indicators of the adaptation reserve in patients with epilepsy. The development of an acute vascular event may increase the frequency of seizures and the presence of paroxysmal EEG phenomena. HRV is more informative to determine the oncoming of the seizure, than the routine ECG. Levetiracetam and lamotrigine have a more favorable effect on the autonomic balance of the heart than carbamazepine and valproic acid.

Distinct α- and β-band rhythms over rat somatosensory cortex with similar properties as in humans

We demonstrate distinct α- (7–14 Hz) and β-band (15–30 Hz) rhythms in rat somatosensory cortex in vivo using epidural electrocorticography recordings. Moreover, we show in rats that a genuine β-rhythm coexists alongside β-activity that reflects the second harmonic of the arch-shaped somatosensory α-rhythm. This demonstration of a genuine somatosensory β-rhythm depends on a novel quantification of neuronal oscillations that is based on their rhythmic nature: lagged coherence. Using lagged coherence, we provide two lines of evidence that this somatosensory β-rhythm is distinct from the second harmonic of the arch-shaped α-rhythm. The first is based on the rhythms' spatial properties: the α- and β-rhythms are demonstrated to have significantly different topographies. The second is based on the rhythms' temporal properties: the lagged phase-phase coupling between the α- and β-rhythms is demonstrated to be significantly less than would be expected if both reflected a single underlying nonsinusoidal rhythm. Finally, we demonstrate that 1) the lagged coherence spectrum is consistent between signals from rat and human somatosensory cortex; and 2) a tactile stimulus has the same effect on the somatosensory α- and β-rhythms in both rats and humans, namely suppressing them. Thus we not only provide evidence for the existence of genuine α- and β-rhythms in rat somatosensory cortex, but also for their homology to the primate sensorimotor α- and β-rhythms.

The dynamic of brain rhythms after neurofeedback course

In this article there is comparative analysis of cerebrum biopotentials of sportsmen in different periods after the end of neurofeedback course. It was revealed the character of late effects has depended on success of the training and period it’s end. For sportsmen studying increase the alpha-rhythm power arbitrarily it is typical: the alpha-rhythm power of both hemispheres increased strait a way after training with closed eyes and during 3 months with opened eyes which in a year was being slow decreased. The values of β- and θ-rhythms were slow decreased in 6—12 months. For sportsmen how were held training unsuccessfully it is typical increasing of alpha-rhythm power in a year, which didn’t depend on decreasing of visual afferentation. The changings of θ-rhythm had wavy character, the β-rhythm power was being decreased.