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.

Changes in EEG patterns in the α-frequency band following BCI-based therapy in children with cerebral palsy

It was demonstrated previously that neurorehabilitation with the BCI-controlled robotic device Exohand-2 combined with conventional therapeutic modalities resulted in significant motor improvement in children with cerebral palsy. However, EEG records were not analyzed in the previous study. The aim of this paper was to describe the reactivity patterns of the EEG α-rhythm during a series of 10 BCI-based neurorehabilitation sessions. The study was carried out in 32 boys and girls aged 10 to 18 years with right- or left-side hemiparesis. EEG was recorded from 21 electrodes at rest and during kinesthetic imagery of finger extension. During the first session, patterns of α-rhythm reactivity during motor imagery differed between patients with left- and right-side hemiparesis. The differences were statistically significant at Р2 during left hand movement rehearsal (F1, 30 = 5.10; p < 0.05). During the final session, the pattern of α-rhythm reactivity was different: synchronization was taken over by desynchronization at some electrode sites, suggesting increased activity of the neocortex. The most conspicuous EEG changes were observed in children with left-side hemiparesis (F20, 300 = 1.84; p < 0.05). By the end of the rehabilitation course, the differences between patients with left-and right-side hemiparesis became much less pronounced. Rearrangements in the EEG patterns in the α-frequency band can be regarded as signs of beneficial reorganization of neural circuits responsible for planning and executing complex hand movements.

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.

Revealing α oscillatory activity using voltage-sensitive dye imaging in monkey V1

The relevance of α oscillations (7-12Hz) in neural processing, although recognized long ago, remains a major research question in the field. While intensively studied in humans, α oscillations appear much less often investigated (and observed) in monkeys. Here we wish to provide data from non-human primates on stimulus-related α rhythm. Indeed, in humans, EEG α is enhanced in response to non-periodic dynamic visual stimulation (“perceptual echoes” or to a static stimulus (“flickering wheel illusion”). Do the same visual patterns induce an oscillatory response in monkey V1? We record voltage-sensitive dye signals from three anesthetized monkeys to investigate the population-based oscillatory neural response that is not resulting from attention-related feedback signals. We revealed α oscillations in monkey V1 which, when they occur, react in a manner comparable to human studies.

Evaluation of the effectiveness of single session audiovisual stimulation for the organism functional state’s correction

Based on the analysis of the changes in the bioelectrical activity of the brain, the dynamics of cerebral blood flow and the vegetative balance of the body, the efficacy of a single 15-minute session of audiovisual stimulation for the correction of the functional state of the organism was evaluated. It was found that after the audiovisual stimulation session, the mean value of the alpha-rhythm power in the frontal, anterior-parietal and occipital leads of the right and left hemispheres of the brain was statistically significant more than in the background study. Such a change in the power of the alpha-rhythm reflects the level of ascending activation necessary for the organization of adaptive behavior, and can also characterize the intensity of the neuro-emotional stress. Increasing the power of the α-rhythm indicates a decrease in the level of nonspecific cerebral activation and is one of the main characteristics of the state of functional comfort. Statistically significant ifferences in the indices of powers of the β - and β -rhythms inherent in the state of active wakefulness were determined. The decrease1 2in the power index of the electoencephalography delta rhythm was revealed. The revealed dynamics of cerebral blood flow parameters was subject to pronounced individual differences, which made it impossible to determine the direction of the trend. It was established a gradual decrease in the power of the low-frequency component of the cardiorhythm with simultaneous increase in the contribution power of the high-frequency component, reaching a statistically significant difference at the last stage of registration, which leads to a significant decrease in the coefficient of vagosympathetic balance after the audiovisual stimulation session. The revealed changes indicate a decrease in the tone of the sympathetic part of the autonomic nervous system. Thus, it is established that after a single 15-minute audiovisual stimulation session, the value of the α-rhythm power in the frontal, anterior parietal and occipital leads of the right and left hemispheres of the brain increases, the power indices of the beta and delta rhythms of the electoencephalography decrease, the stress index and the vegetative index decrease balance, and also the coefficient of the vagosympathetic balance of the rhythmocardiogram. These changes characterize the optimization of the functional state of the organism and contribute to an accelerated restoration of working capacity.