scholarly journals Formation of attention in men and women during tasks performance with high cognitive load

Author(s):  
M. Bondarenko ◽  
O. Bondarenko ◽  
V. Kravchenko ◽  
M. Makarchuk

The differences in brain mechanisms that underlie the switch between involuntary and voluntary attention associated with gender were investigated. We compared reaction time, the number of errors and the electrical activity of the brain during the Emotional Stroop test on the background of visual content that contained affective images when presenting stimuli through a dominant and non-dominant eye in 20 men and 20 women. The model of significant cognitive load was created, when it is quite difficult to correctly respond to the relevant characteristics of the stimulus. Different patterns of brain activity have been found: in women, this task is accompanied by an increase in spectral power in the theta range of the predominantly left hemisphere; in men, the power of alpha rhythm in the parietal-occipital associative cortex decreases with the local increase of theta rhythm in the posterior-frontal areas and beta-rhythm in left prefrontal zone. Under the conditions of high cognitive load created by the distracting visual content and the perception of visual stimuli through the non-dominant eye, the brain mechanisms of voluntary attention provide a more thorough analysis of the relevant stimuli in women that is seen in accurate responses over a longer period in comparison with men.

2017 ◽  
Vol 8 (4) ◽  
pp. 72-90 ◽  
Author(s):  
T.A. Aiusheeva ◽  
A.E. Saprygin ◽  
A.N. Savostyanov ◽  
V.V. Stеpanova

The aim of the study is to compare behavioral and EEG reactions of primary school-aged children during the recognition of syntactic errors in emotionally (positively or negatively) colored sentences that appeal to the choice of the child differently. 20 children (mean age 9,0±0,3 years, 12 boys, 8 girls) were examined. We found out that the children with a high quality of solving a linguistic task concentrate all their attention on finding an error in the sentences, and children with a low quality of solving a task demonstrate increased emotionality, possibly connected with their unsuccessfulness. The strongest EEG reactions in the ranges of alpha- and theta- rhythms were recorded in children with slow speed and bad quality of the solution of the task. The recognition of sentences with negative emotions took longer than sentences with positive emotions. The increase of emotions (synchronization in theta range) during the recognition of negative sentences was provoked by the expectation of failure and “identification” with it. The children found the mistake better in the sentences with their own choice than in the sentences that describes the forced-choice situation. Desynchronization (i.e. decrease in the spectral power) and synchronization (i.e. increase in spectral power) was detected on the EEG in the alpha-rhythm range. Desynchronization was associated with the recognition of sentences describing the children’s own choice; synchronization was recorded when recognizing sentences describing the forced-choice situation.


Author(s):  
M.N. Ustinin ◽  
S.D. Rykunov ◽  
A.I. Boyko ◽  
O.A. Maslova ◽  
K.D. Walton ◽  
...  

New method for the magnetic encephalography data analysis was proposed. The method transforms multichannel time series into the spatial structure of the human brain activity. In this paper we further develop this method to determine the dominant direction of the electrical sources of brain activity at each node of the calculation grid. We have considered the experimental data, obtained with three 275-channel magnetic encephalographs in New York University, McGill University and Montreal University. The human alpha rhythm phenomenon was selected as a model object. Magnetic encephalograms of the brain spontaneous activity were registered for 5-7 minutes in magnetically shielded room. Detailed multichannel spectra were obtained by the Fourier transform of the whole time series. For all spectral components, the inverse problem was solved in elementary current dipole model and the functional structure of the brain activity was calculated in the frequency band 8-12 Hz. In order to estimate the local activity direction, at the each node of calculation grid the vector of the inverse problem solution was selected, having the maximal spectral power. So, the 3D-map of the brain activity vector field was produced – the directional functional tomogram. Such maps were generated for 15 subjects and some common patterns were revealed in the directions of the alpha rhythm elementary sources. The proposed method can be used to study the local properties of the brain activity in any spectral band and in any brain compartment.


2020 ◽  
Vol 6 (24) ◽  
pp. eaba8792 ◽  
Author(s):  
Rui Zhang ◽  
Wei Xiao ◽  
Yudong Ding ◽  
Yulong Feng ◽  
Xiang Peng ◽  
...  

Understanding the relationship between brain activity and specific mental function is important for medical diagnosis of brain symptoms, such as epilepsy. Magnetoencephalography (MEG), which uses an array of high-sensitivity magnetometers to record magnetic field signals generated from neural currents occurring naturally in the brain, is a noninvasive method for locating the brain activities. The MEG is normally performed in a magnetically shielded room. Here, we introduce an unshielded MEG system based on optically pumped atomic magnetometers. We build an atomic magnetic gradiometer, together with feedback methods, to reduce the environment magnetic field noise. We successfully observe the alpha rhythm signals related to closed eyes and clear auditory evoked field signals in unshielded Earth’s field. Combined with improvements in the miniaturization of the atomic magnetometer, our method is promising to realize a practical wearable and movable unshielded MEG system and bring new insights into medical diagnosis of brain symptoms.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Chi Jung Hung ◽  
Daisuke Ono ◽  
Thomas S Kilduff ◽  
Akihiro Yamanaka

Orexin/hypocretin-producing and melanin-concentrating hormone-producing (MCH) neurons are co-extensive in the hypothalamus and project throughout the brain to regulate sleep/wakefulness. Ablation of orexin neurons decreases wakefulness and results in a narcolepsy-like phenotype, whereas ablation of MCH neurons increases wakefulness. Since it is unclear how orexin and MCH neurons interact to regulate sleep/wakefulness, we generated transgenic mice in which both orexin and MCH neurons could be ablated. Double-ablated mice exhibited increased wakefulness and decreased both rapid eye movement (REM) and non-REM (NREM) sleep. Double-ablated mice showed severe cataplexy compared with orexin neuron-ablated mice, suggesting that MCH neurons normally suppress cataplexy. Double-ablated mice also showed frequent sleep attacks with elevated spectral power in the delta and theta range, a unique state that we call ‘delta-theta sleep’. Together, these results indicate a functional interaction between orexin and MCH neurons in vivo that suggests the synergistic involvement of these neuronal populations in the sleep/wakefulness cycle.


Author(s):  
M.N. Ustinin ◽  
S.D. Rykunov ◽  
A.I. Boyko ◽  
O.A. Maslova

New method for the data analysis was proposed, making it possible to transform multichannel time series into the spatial structure of the system under study. The method was successfully used to investigate biological and physical objects based on the magnetic field measurements. In this paper we further develop this method to analyze the data of the experiments where the electric field is measured. The brain activity in the state of subject “eyes closed” was registered by the 19-channel electric encephalograph, using the 10-20 scheme. The electroencephalograms were obtained in resting state and with arbitrary hands motions. Detailed multichannel spectra were obtained by the Fourier transform of the whole time series. All spectral data revealed the broad alpha rhythm peak in the frequency band 9-12 Hz. For all spectral components in this band the inverse problem was solved, and the 3D map of the brain activity was calculated. The inverse problem was solved in elementary current dipole model for one-layer spherical conductor without any restrictions for the source position. The combined analysis of the magnetic resonance image and the brain functional structure leads to the conclusion that this structure generally corresponds to the modern knowledge about the alpha rhythm. The 3D map of the vector field of the dominating directions of the alpha rhythm sources was also generated. The proposed method can be used to study the spatial distribution of the brain activity in any spectral band of the electroencephalography data.


2021 ◽  
Vol 6 (2) ◽  
pp. 66-74
Author(s):  
I. V. Tarasova ◽  
M. S. Nikitenko ◽  
O. A. Trubnikova ◽  
I. N. Kukhareva ◽  
D. S. Kupriyanova ◽  
...  

Aim. To estimate psychophysiological changes during workspace virtualization.Materials and Methods. We evaluated the psychophysiological profile of 10 healthy right-handed males aged 25 to 45 years before, during and after the working in a virtual reality (VR) headset. All participants had higher education, normal or corrected to normal vision, and were experienced computer users. Psychometric testing included a neurological examination, assessment of functional and feedback-related brain activity (reaction time, errors, and missed signals) and attention span, quantification of processed symbols in the 1st and 4th minutes of Bourdon test, analysis of short-term memory (10 words, 10 numbers and 10 meaningless syllables memorization) and spatial perception, and multi-channel electroencephalography recording in rest.Results. Deterioration of psychometric indicators after a cognitive load in a VR headset was documented only in the most difficult tasks: the number of errors increased by 93% in the brain performance test and by 65% in the attention distribution test. The analysis of electroencephalography data showed that the delta rhythm and theta1 rhythm activity decreased by 28 and 13%, respectively, after working in a VR headset as compared to baseline values, while alpha1 rhythm activity increased by 96%. Probably, the observed electroencephalography changes corresponded to the patterns of brain activation associated with cognitive load and the resulting fatigue.Conclusions. We developed a suitable approach for the psychometric testing before and after working in VR headset, which demonstrated general tolerance and acceptable subjective difficulties to VR load. 


2019 ◽  
Author(s):  
Chi Jung Hung ◽  
Daisuke Ono ◽  
Thomas S. Kilduff ◽  
Akihiro Yamanaka

SummaryOrexin/hypocretin-producing and melanin-concentrating hormone-producing (MCH) neurons are co-extensive in the tuberal hypothalamus and project throughout the brain to regulate sleep/wakefulness. Ablation of orexin neurons in mice decreases wakefulness and results in a narcolepsy-like phenotype, whereas ablation of MCH neurons increases wakefulness. Since it is unclear how orexin and MCH neurons interact to regulate sleep/wakefulness, we generated conditional transgenic mice in which both orexin and MCH neurons could be ablated. Double-ablated mice exhibited increased wakefulness and decreased both rapid eye movement (REM) and non-REM (NREM) sleep. The total time in cataplexy and the mean cataplexy bout duration increased significantly in double-ablated mice compared with orexin neuron-ablated mice, suggesting that MCH neurons normally suppress cataplexy and that compromised MCH neurons may exacerbate symptoms in some narcoleptic patients. Double-ablated mice also showed frequent sleep attacks with elevated spectral power in the delta and theta range during wakefulness, a state with EEG characteristics indistinguishable from the transition from NREM into REM sleep. Together, these results indicate a functional interaction between orexin and MCH neurons in vivo that suggests the synergistic involvement of these neuronal populations in the sleep/wakefulness cycle.


2016 ◽  
Vol 24 (2) ◽  
Author(s):  
O. G. Berchenko ◽  
D. O. Bevzyuk ◽  
N. O. Levicheva ◽  
S. P. Koladko

The aim of our research was to study the limbic-neocortical mechanisms of addictive behaviour in rats formed throughthe arousal of intense emotions on the model of self-stimulation reaction of the brain. We carried out investigations by conducting a chronic experiment on 15 nonlinear laboratory male rats weighing 250 to 320 grams, at the ages of 5 to 6 months. As a model of receiving positive emotions we used the behaviour of animals held in a Skinner box which was formed through self stimulation of the positive emotional zones of the posterior ventrolateral hypothalamus. We registered the frequency of self-stimulation reactions of the ventrolateral hypothalamus daily for 4 days and on the 7th day after its ccessation (state of deprivation). We performed visual and spectral analysis of the electrical activity of the brain using "Neuron-spektr.net" software. We assessed the absolute spectral density of the power of rhythm signals of the following frequency bands: delta (0.5–4.0 Hz), theta (4.0–7.0 Hz), alpha (8.0–12.0 Hz) and low frequency beta (14.0–20.0 Hz). The formation of behaviour dependent on receiving intense emotions as a result of self-stimulation of the positive zones of the ventrolateral hypothalamus is caused by the initial high level of need for positive emotional reinforcement and further growth in the implementation of desire and is associated with activation of emotional memory mechanisms, changes in electrogenesis in the hippocampus and the reticular formation in the form of decrease in the spectral power of rhythms of alpha and beta bands and increased spectral power of biopotentials of the delta range in the hippocampus and theta range in the reticular formation with severe manifestations of seizure and paroxysmal activity components and increased activity of the sympatho-adrenal system. The syndrome of withdrawal fromthe receiving of positive emotions in some rats with implementation of a programme of a phobic character with an increase in beta rhythms in all thestudied structures, and among other rats with implementation of a programme of an aggressive character, which was characterized by increased electrical seizure activity in the hippocampus, is caused by oppression of electrogenesis in the hypothalmus and replacement of slow wave activity in the reticular formation at high frequency rhythms in the alpha-theta range. 


2018 ◽  
Vol 20 (1) ◽  
pp. 7-12
Author(s):  
O E Gurskaya ◽  
V N Tsygan ◽  
A V Mirolubov

Electrophysiological characteristics of patients with encephalopathy of different etiology are presented. Pathogenic mechanisms affecting the electroencephalographic pattern and quantitative components of electroencephalogram are discussed. The aim of the study was to determine a universal quantitative electrophysiological criterion for the evaluation of neurodegenerative changes in the brain of patients with encephalopathy. We analyzed the data of anamnesis, neurological examination, laboratory tests and electroencephalograms from 389 patients with encephalopathy of post-traumatic, infectious, vascular and mixed etiology. Spectral analysis of electroencephalograms was performed and the values of relative quantitative electrophysiological criterion - the ratio of spectral power in the alpha/theta ranges at rest and during the test with hyperventilation were counted. The ratio of spectral power in the alpha/theta ranges was the lowest in patients of older age group and low - in patients with encephalopathy of infectious etiology. The ratio of the spectral power in the alpha-theta ranges in patients with post-traumatic encephalopathy was significantly different depending on the severity of the traumatic brain injury - mild or moderate/severe. We studied the possibilities of practical application of selected electrophysiological criterion - the ratio of spectral power of rhythms in the alpha-theta ranges. We counted this criterion in 150 patients with encephalopathy for the effectiveness evaluation of the neuroprotective therapy with сortexin. The chosen electrophysiological criterion had proved its effectiveness in therapy monitoring in patients with encephalopathy. In this article we demonstrated the advantages of additional neuroprotective therapy with сortexin. Increase in spectral power of alpha rhythm and decrease in spectral power of slow-wave components in the electroencephalographic pattern characterizes successful neuroprotective therapy with neuropeptides, such as сortexin.


2015 ◽  
Vol 69 (1-2) ◽  
pp. 21-29
Author(s):  
Ljiljana Martac

We used animal model of neurotoxicity in rats, which provided the possibility of studying biological pathophysiological phenomena in vivo and afterwards in vitro conditions. The analysis of electrocortical brain activity using mathematical methods can describe the changes induced by aluminum intoxication in rat as an animal model. In physiological and pathophysiological conditions, on experimental models, mechanisms related to changes in behavior, plasticity and accumulation of aluminum in nervous tissue of the rat brain were observed. Animal models of rats used in the experiments described changes in the group of neuronal activity in the brain of rats in different modes of intoxication aluminum. This study describes ECoG activity in the brain of rats under anesthesia in both the control and aluminum treated animals. Fractal and spectral analysis was used to present qualitative and quantitative changes in the conditions of neurotoxicity. Changes in neurotransmission, as well as the structure and function of the neural network are connected to the molecular-physiological mechanisms of neurotoxicity. Aluminium toxicity was monitored through changes in glutamatergic activity and calcium channel activity. By spectrum analysis neurotoxicity was described through changes in spectral power in the corresponding frequency ranges. By comparing the FD of intoxicated and control individuals there was obtained the range of the change in correlation with the corresponding pathophysiological conditions of intoxication. The shange in FD might be an indication of neurotoxicity.


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