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1.
Cogn Emot ; : 1-12, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38973177

RESUMO

The present study aimed to explore the effectiveness of two typical intrapersonal strategies (cognitive reappraisal, CR; expressive suppression, ES) on interpersonal emotion regulation (IER), and uncover the physiological synchrony pattern underlying this. A sample of 90 friend dyads (N = 180) was randomly assigned to the CR, the ES, or the control group. In each dyad, the target underwent a negative emotional task (induce sadness by recalling a negative event), and the regulator was assigned to implement the CR strategy, the ES strategy, or no action to down-regulate the targets' negative emotions. Self-reported results showed that compared to the control group, both CR and ES strategies decreased the targets' negative emotions, and increased the targets' positive emotions, indicating a successful IER effect. And the ECG results revealed that relative to the control condition, both CR and ES strategies evoked stronger physiological synchrony (heart rate synchrony and heart rate variation synchrony) during the emotion regulation stage of IER. Overall, these findings demonstrated the similar efficacy of reappraisal and suppression strategies implemented by the regulators to improve the targets' negative emotions, and suggested that the physiological synchrony might have an important relational meaning during the IER process.

2.
Entropy (Basel) ; 26(10)2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39451932

RESUMO

In the past two decades, research in the field of chaotic synchronization has attracted extensive attention from scholars, and at the same time, more synchronization methods, such as chaotic master-slave synchronization, projection synchronization, sliding film synchronization, fractional-order synchronization and so on, have been proposed and applied to chaotic secure communication. In this paper, based on radial basis function neural network theory and the particle swarm optimisation algorithm, the RBFNN-PSO synchronisation method is proposed for the Sprott B chaotic system with external noise. The RBFNN controller is constructed, and its parameters are used as the particle swarm particle optimisation parameters, and the optimal values of the controller parameters are obtained by the PSO training method, which overcomes the influence of external noise and achieves the synchronisation of the master-slave system. Then, it is shown by numerical simulation and analysis that the scheme has a good performance against external noise. Because the Sprott B system has multiple chaotic attractors with richer dynamics, the synchronization system based on Sprott B chaos is applied to the image encryption system. In particular, the Zigzag disambiguation method for top corner rotation and RGB channel selection is proposed, and the master-slave chaotic system synchronisation sequences are diffused to the disambiguated data streams, respectively. Therefore, the encryption and decryption of image transmission are implemented and the numerical simulation results are given, the random distribution characteristics of encrypted images are analysed using histogram and Shannon entropy methods, and the final results achieve the expected results.

3.
Neuroimage ; 265: 119801, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36496181

RESUMO

Post-task responses (PTRs) are transitionary responses occurring for several seconds between the end of a stimulus/task and a period of rest. The most well-studied of these are beta band (13 - 30 Hz) PTRs in motor networks following movement, often called post-movement beta rebounds, which have been shown to differ in patients with schizophrenia and autism. Previous studies have proposed that beta PTRs reflect inhibition of task-positive networks to enable a return to resting brain activity, scaling with cognitive demand and reflecting cortical self-regulation. It is unknown whether PTRs are a phenomenon of the motor system, or whether they are a more general self-modulatory property of cortex that occur following cessation of higher cognitive processes as well as movement. To test this, we recorded magnetoencephalography (MEG) responses in 20 healthy participants to a working-memory task, known to recruit cortical networks associated with higher cognition. Our results revealed PTRs in the theta, alpha and beta bands across many regions of the brain, including the dorsal attention network (DAN) and lateral visual regions. These PTRs increased significantly (p < 0.05) in magnitude with working-memory load, an effect which is independent of oscillatory modulations occurring over the task period as well as those following individual stimuli. Furthermore, we showed that PTRs are functionally related to reaction times in left lateral visual (p < 0.05) and left parietal (p < 0.1) regions, while the oscillatory responses measured during the task period are not. Importantly, motor PTRs following button presses did not modulate with task condition, suggesting that PTRs in different networks are driven by different aspects of cognition. Our findings show that PTRs are not limited to motor networks but are widespread in regions which are recruited during the task. We provide evidence that PTRs have unique properties, scaling with cognitive load and correlating significantly with behaviour. Based on the evidence, we suggest that PTRs inhibit task-positive network activity to enable a transition to rest, however, further investigation is required to uncover their role in neuroscience and pathology.


Assuntos
Encéfalo , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Encéfalo/fisiologia , Magnetoencefalografia/métodos , Cognição/fisiologia , Tempo de Reação
4.
Exp Brain Res ; 241(3): 875-887, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36788141

RESUMO

Human movement synchronisation with moving objects strongly relies on visual input. However, auditory information also plays an important role, since real environments are intrinsically multimodal. We used electroencephalography (EEG) frequency tagging to investigate the selective neural processing and integration of visual and auditory information during motor tracking and tested the effects of spatial and temporal congruency between audiovisual modalities. EEG was recorded while participants tracked with their index finger a red flickering (rate fV = 15 Hz) dot oscillating horizontally on a screen. The simultaneous auditory stimulus was modulated in pitch (rate fA = 32 Hz) and lateralised between left and right audio channels to induce perception of a periodic displacement of the sound source. Audiovisual congruency was manipulated in terms of space in Experiment 1 (no motion, same direction or opposite direction), and timing in Experiment 2 (no delay, medium delay or large delay). For both experiments, significant EEG responses were elicited at fV and fA tagging frequencies. It was also hypothesised that intermodulation products corresponding to the nonlinear integration of visual and auditory stimuli at frequencies fV ± fA would be elicited, due to audiovisual integration, especially in Congruent conditions. However, these components were not observed. Moreover, synchronisation and EEG results were not influenced by congruency manipulations, which invites further exploration of the conditions which may modulate audiovisual processing and the motor tracking of moving objects.


Assuntos
Percepção Auditiva , Percepção Visual , Humanos , Percepção Auditiva/fisiologia , Percepção Visual/fisiologia , Eletroencefalografia , Som , Fatores de Tempo , Estimulação Acústica , Estimulação Luminosa
5.
Somatosens Mot Res ; : 1-10, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36921090

RESUMO

PURPOSE: Event-related desynchronisation (ERD) and event-related synchronisation (ERS) reflect pain perception and integration of the nociceptive sensory inputs. This may contribute to the understanding of how neurophysiological markers of Knee Osteoarthritis (KOA) patients can differ from control individuals, which would improve aspects such as prediction and prognosis. We performed a cross-sectional analysis of our cohort study (DEFINE cohort), KOA arm, with 71 patients, compared with 65 control participants. The study aimed to examine possible differences between ERD and ERS in control participants compared to Knee Osteoarthritis (KOA) patients when adjusting for important covariates. MATERIALS AND METHODS: We performed independent multivariate regression models considering as dependent variables the power value related to ERD and ERS for four different sensorimotor tasks (Motor Execution, Motor Imagery, Active Observation and Passive Observation) and four sensorimotor oscillations (Alpha, Beta, Low Beta, and High Beta), each model, controlled by age and sex. RESULTS: We demonstrate that the differences between KOA and healthy subjects are frequency specific, as most differences are in the beta bandwidth range. Also, we observed that subjects in the KOA group had significantly higher ERD and ERS. This may be correlated to the amount of lack of brain organisation and a subsequent attempt at compensation induced by KOA. CONCLUSIONS: Our findings strengthen the notion that subjects with KOA have a higher degree of brain plasticity changes that are also likely correlated to the degree of compensation and behavioural dysfunction.

6.
N Z Vet J ; 71(2): 53-64, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36265863

RESUMO

AIMS: To use an evidence-based approach to evaluate the available research data on the efficacy of equine chorionic gonadotropin (eCG) to improve reproductive performance of dairy cows when added to oestrus synchronisation programmes for the treatment of cows not detected in oestrus. METHODS: A rapid literature review was conducted to summarise the existing trial data, primarily the effect of eCG on conception rate (CR) to fixed time artificial insemination (FTAI) from oestrus synchronisation programmes in lactating dairy cows. Relevant papers were identified via databases and auxiliary search strategies, then information was collected using a standardised data collection form. Similar studies were grouped together to create a descriptive summary of CR to FTAI and secondary outcome measures, with the creation of forest plots to visualise results. RESULTS: A total of 15 studies were identified for review: nine examined the administration of 400-500 IU eCG as part of an oestrus synchronisation programme based on intra-vaginal progesterone-releasing devices, gonadotropin-releasing hormone and prostaglandin (P4-GPG programme). The variable methodologies in the trials evaluated posed difficulties in grouping studies for further analysis and meant that there was insufficient data for a full meta-analysis. A single study reported a statistically significant increase in CR to FTAI from the addition to eCG to a P4-GPG programme in cows with anovulatory anoestrous. Four studies evaluated the addition of eCG to P4-GPG programmes in cows without visible oestrous signs; risk differences for CR to FTAI were between -1.7% and 28.8%, with three out of four studies reporting a positive effect of eCG on CR to FTAI, but all 95% CI values crossed the line of no effect. Two studies reported on the effect of eCG on 42-day pregnancy rate following a P4-GPG programme; one reported a risk difference of -4.9% (95% CI = -10.6-0.8%), while the other reported a risk difference of 7.9% (95% CI = 0.8-15%). CONCLUSIONS: The results of published studies describing the effect of eCG in P4-GPG programmes on CR to FTAI are inconsistent and further well-designed, adequately powered studies with standardised outcome measures are required to investigate its effect.


Assuntos
Lactação , Progesterona , Gravidez , Feminino , Bovinos , Animais , Cavalos , Reprodução , Fertilização , Sincronização do Estro/métodos , Inseminação Artificial/veterinária , Gonadotropina Coriônica/farmacologia
7.
Ergonomics ; 66(5): 690-703, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35959646

RESUMO

We aimed to investigate the alpha (α) activity in operators experiencing boredom while performing prolonged monitoring and prospective memory tasks using different processing mechanisms. Fifty-four participants underwent electroencephalography (EEG) and were found to have poorer prospective memory performance under top-down conditions. Further, α power and synchronisation were higher during bottom-up than in top-down processes, revealing an inhibition effect of the former. Significant differences in brain regions and hemispheres were identified to distinguish different cognitive processes in both information-processing mechanisms. Thus, people are likely to cope with boredom differently in terms of top-down and bottom-up processes. Specifically, a higher attention level was reported during top-down processing, to mitigate the negative influences of boredom. Overall, this study provides EEG evidence which suggests that prospective memory can be enhanced in top-down processing during prolonged monitoring tasks by increasing the salience of cues.


Boredom is a growing problem as tasks requiring monitoring increase. We explored how people process information to perform prospective memory tasks while monitoring. The prospective memory was poorer during top-down processing, but stronger cortical activation indicated an inhibitory effect on inattention. Information-processing mechanisms are suggested for designing boredom interventions.


Assuntos
Memória Episódica , Humanos , Tédio , Eletroencefalografia , Encéfalo , Atenção/fisiologia
8.
J Vis Commun Med ; 46(1): 19-29, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35726167

RESUMO

Despite the recent advancement of virtual education during the last pandemic, mastering clinical competencies remains challenging. The current study endorsed Synchronised Video-assisted Clinical Skill lab Sessions (SVCSLS) as a novel instructional design aiming to improve medical students' clinical competencies during virtual learning. The current study is a mixed-method study that was carried out among 210 medical students at a medical college in Saudi Arabia. It was revealed that students viewed SVCSLSs as an effective and safe tool during times of crisis. Students' performance did not show significant variations in all program phases compared with face-to-face learning. SVCSLSs has many advantages, including enjoyment, continuous access to learning material, Self-Directed Learning, fostering recall and memorisation, and enhancing higher cognitive skills. Students suggested that the sessions' content be updated, that workplace-related videos be added, and that constructive feedback is provided. Students recommended updating the contents of the sessions, enriching them with workplace-based videos, and providing constructive feedback. Though SVCSLSs have been proven to be an effective tool, we recommend using them during a crisis rather than replacing the face-to-face mode of learning in normal circumstances.


Assuntos
Meios de Comunicação , Educação Médica , Estudantes de Medicina , Humanos , Competência Clínica , Aprendizagem
9.
BMC Genomics ; 23(1): 363, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35546662

RESUMO

BACKGROUND: Cervical artificial insemination (AI) with frozen-thawed semen results in unacceptably low pregnancy rates internationally. The exception is in Norway, where vaginal deposition of frozen-thawed semen to a natural oestrous routinely yields pregnancy rates in excess of 70%. Previous studies by our group has demonstrated that this is due to differences in cervical sperm transport. However, a potentially important contributory factor is that ewes are inseminated to a natural oestrous in Norway but to a synchronised oestrous across most of the rest of the world. In this study, we interrogated the gene expression of the sheep cervix of four ewe breeds with known differences in pregnancy rates following cervical AI using frozen-thawed semen under the effect of exogenous hormones to synchronise the oestrous cycle. These four ewe breeds (n = 8 to 11 ewes per breed) are from two countries: Ireland (Belclare and Suffolk; medium and low fertility, respectively) and Norway (Norwegian White Sheep (NWS) and Fur; both with high fertility compared to the Irish ewe breeds). RESULTS: RNA extracted from cervical biopsies collected from these breeds was analysed by RNA-sequencing and differential gene expression analysis. Using the low-fertility Suffolk breed as a reference level; 27, 1827 and 2641 genes were differentially expressed in Belclare, Fur and NWS ewes, respectively (P <  0.05 and FC > 1.5). Gene ontology (GO) analysis revealed that Fur and NWS had an up-regulation of enriched pathways involved in muscle contraction and development compared to Suffolk. However, there was a down-regulation of the immune response pathway in NWS compared to Suffolk. In addition, GO analysis showed similar expression patterns involved in muscle contraction, extracellular matrix (ECM) development and cell-cell junction in both Norwegian ewe breeds, which differed to the Irish ewe breeds. CONCLUSIONS: This novel study has identified a number of conserved and breed-specific biological processes under the effect of oestrous synchronisation that may impact cervical sperm transport during the follicular phase of the reproductive cycle.


Assuntos
Colo do Útero , Fase Folicular , Animais , Colo do Útero/fisiologia , Feminino , Inseminação Artificial/veterinária , Masculino , Gravidez , RNA , Ovinos/genética , Transcriptoma
10.
Curr Genet ; 68(1): 69-81, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34633492

RESUMO

Glycolysis is the central metabolic pathway of almost every cell and organism. Under appropriate conditions, glycolytic oscillations may occur in individual cells as well as in entire cell populations or tissues. In many biological systems, glycolytic oscillations drive coherent oscillations of other metabolites, for instance in cardiomyocytes near anorexia, or in pancreas where they lead to a pulsatile release of insulin. Oscillations at the population or tissue level require the cells to synchronize their metabolism. We review the progress achieved in studying a model organism for glycolytic oscillations, namely yeast. Oscillations may occur on the level of individual cells as well as on the level of the cell population. In yeast, the cell-to-cell interaction is realized by diffusion-mediated intercellular communication via a messenger molecule. The present mini-review focuses on the synchronisation of glycolytic oscillations in yeast. Synchronisation is a quorum-sensing phenomenon because the collective oscillatory behaviour of a yeast cell population ceases when the cell density falls below a threshold. We review the question, under which conditions individual cells in a sparse population continue or cease to oscillate. Furthermore, we provide an overview of the pathway leading to the onset of synchronized oscillations. We also address the effects of spatial inhomogeneities (e.g., the formation of spatial clusters) on the collective dynamics, and also review the emergence of travelling waves of glycolytic activity. Finally, we briefly review the approaches used in numerical modelling of synchronized cell populations.


Assuntos
Glicólise , Saccharomyces cerevisiae , Contagem de Células , Modelos Biológicos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
11.
Mult Scler ; 28(3): 492-495, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34726562

RESUMO

BACKGROUND: In a case report of a progressive multiple sclerosis with cerebellar impairments, we reported that synchronisation of steps to beats was possible only at -12% of usual walking cadence during 1 minute of walking. OBJECTIVES AND METHODS: Here, we investigate the effect of synchronisation using two different alignment approaches on the patient's gait pattern over 2 minutes of walking, compared to walking in silence. RESULTS AND CONCLUSION: This proof of concept showed that the adaptive approach was successful resulting in an improved gait pattern compared to the other conditions, providing preliminary evidence to support a full-scale intervention study.


Assuntos
Ataxia Cerebelar , Esclerose Múltipla , Música , Ataxia Cerebelar/etiologia , Marcha , Humanos , Caminhada
12.
Biol Cybern ; 116(4): 461-473, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35538379

RESUMO

Experimental and theoretical studies have shown that ephaptic coupling leads to the synchronisation and slowing down of spikes propagating along the axons within peripheral nerve bundles. However, the main focus thus far has been on a small number of identical axons, whereas realistic peripheral nerve bundles contain numerous axons with different diameters. Here, we present a computationally efficient spike propagation model, which captures the essential features of propagating spikes and their ephaptic interaction, and facilitates the theoretical investigation of spike volleys in large, heterogeneous fibre bundles. We first lay out the theoretical basis to describe how the spike in an active axon changes the membrane potential of a passive axon. These insights are then incorporated into the spike propagation model, which is calibrated with a biophysically realistic model based on Hodgkin-Huxley dynamics. The fully calibrated model is then applied to fibre bundles with a large number of axons and different types of axon diameter distributions. One key insight of this study is that the heterogeneity of the axonal diameters has a dispersive effect, and that a higher level of heterogeneity requires stronger ephaptic coupling to achieve full synchronisation between spikes.


Assuntos
Axônios , Fibras Nervosas , Potenciais de Ação/fisiologia , Axônios/fisiologia , Potenciais da Membrana , Nervos Periféricos
13.
Cogn Emot ; 36(8): 1458-1463, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36951205

RESUMO

Smooth social interaction requires interindividual coordination. This Theory Section addresses the nature of the processes involved and the potential dangers of malfunctioning coordination. In her invited article, Butler provides a general overview of the processes involved, including interpersonal synchronisation, and advocates a dynamic systems framework for further research. In their commentary, Carré and Cornejo concur in principle but highlight the importance of the meaning attributed to the spontaneous expressive movements in naturally occurring interactions and the nature of the respective social situations. Suhay, in her commentary from a political science perspective, highlights the need for synergy based on social coordination for successful democratic governing. In commenting on the problem of political polarisation because of malfunctioning social coordination, introduced by Butler, Suhay adds the important role played by social identity and emotion. Of particular importance are affective reactions based on "evaluative biases" in favour of information that bolsters one's views and rejection of information that challenges them. I conclude this editorial by referring to recent data on affective polarisation, pleading for more multidisciplinary research on the phenomenon, and arguing for a more substantial contribution from the cognitive and emotion sciences. In particular, I outline the "predictive coding" framework and the potential contributions from emotion science.


Assuntos
Emoções , Interação Social , Humanos
14.
Sensors (Basel) ; 22(3)2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35161855

RESUMO

This paper presents the design of a low-cost, compact instrumentation system to enable six degree of freedom motion tracking of acetal bricks within an experimental model of a cracked Advanced Gas-Cooled Reactor (AGR) core. The system comprises optical and inertial sensors and capitalises on the advantages offered by data fusion techniques. The optical system tracks LED indicators, allowing a brick to be accurately located even in cluttered images. The LED positions are identified using a geometrical correspondence algorithm, which was optimised to be computationally efficient for shallow movements, and complex camera distortions are corrected using a versatile Incident Ray-Tracking calibration. Then, a Perspective-Ray-based Scaled Orthographic projection with Iteration (PRSOI) algorithm is applied to each LED position to determine the six degree of freedom pose. Results from experiments show that the system achieves a low Root Mean Squared (RMS) error of 0.2296 mm in x, 0.3943 mm in y, and 0.0703 mm in z. Although providing an accurate measurement solution, the optical tracking system has a low sample rate and requires the line of sight to be maintained throughout each test. To increase the robustness, accuracy, and sampling frequency of the system, the optical system can be augmented with an Inertial Measurement Unit (IMU). This paper presents a method to integrate the optical system and IMU data by accurately timestamping data from each set of sensors and aligning the two coordinate axes. Once miniaturised, the developed system will be used to track smaller components within the AGR models that cannot be tracked with current instrumentation, expanding reactor core modelling capabilities.


Assuntos
Algoritmos , Modelos Teóricos , Calibragem , Movimento (Física) , Movimento
15.
Neuroimage ; 243: 118564, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34506915

RESUMO

Educational diversity is defined as the diversity of educational backgrounds measured by multiple subjects. This study aimed to unveil the interpersonal neural correlates that underlie the effect of group educational diversity on group creativity. One hundred and sixteen college students were assigned to high educational diversity (HD; the members respectively majored in science or social science) or low educational diversity (LD; the members both majored in either science or social science) groups based on their academic majors. They were required to solve two problems that either demanded creativity (alternative uses task, AUT) or not (object characteristics task). We used functional near-infrared spectroscopy (fNIRS)-based hyperscanning to simultaneously record the neural responses of pairs of interacting participants in each group. The LD group showed more AUT fluency and perspective-taking behaviours than the HD group, whereas no group difference was observed for AUT uniqueness. Additionally, collective flexibility was higher in the HD group than in the LD group. The fNIRS results showed that the interpersonal brain synchronisation (IBS) increments at the right angular gyrus and right primary somatosensory cortex were greater in the LD group than in the HD group. These findings indicate that although high educational diversity benefits cognitive flexibility, it does not necessarily lead to a better idea quality or greater idea quantity. The greater IBS increments and perspective-taking behaviours that we observed in the LD group may account for this.


Assuntos
Criatividade , Escolaridade , Processos Grupais , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Comportamento Cooperativo , Eletroencefalografia , Feminino , Humanos , Relações Interpessoais , Masculino , Lobo Parietal/fisiologia , Resolução de Problemas/fisiologia , Córtex Somatossensorial/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
16.
Neuroimage ; 238: 118209, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34051354

RESUMO

People have a natural and intrinsic ability to coordinate body movements with rhythms surrounding them, known as sensorimotor synchronisation. This can be observed in daily environments, when dancing or singing along with music, or spontaneously walking, talking or applauding in synchrony with one another. However, the neurophysiological mechanisms underlying accurately synchronised movement with selected rhythms in the environment remain unclear. Here we studied real and imagined sensorimotor synchronisation with interleaved auditory and visual rhythms using cortico-muscular coherence (CMC) to better understand the processes underlying the preparation and execution of synchronised movement. Electroencephalography (EEG), electromyography (EMG) from the finger flexors, and continuous force signals were recorded in 20 participants during tapping and imagined tapping with discrete stimulus sequences consisting of alternating auditory beeps and visual flashes. The results show that the synchronisation between cortical and muscular activity in the beta (14-38 Hz) frequency band becomes time-locked to the taps executed in synchrony with the visual and auditory stimuli. Dynamic modulation in CMC also occurred when participants imagined tapping with the visual stimuli, but with lower amplitude and a different temporal profile compared to real tapping. These results suggest that CMC does not only reflect changes related to the production of the synchronised movement, but also to its preparation, which appears heightened under higher attentional demands imposed when synchronising with the visual stimuli. These findings highlight a critical role of beta band neural oscillations in the cortical-muscular coupling underlying sensorimotor synchronisation.


Assuntos
Ritmo beta/fisiologia , Córtex Cerebral/fisiologia , Movimento/fisiologia , Músculo Esquelético/fisiologia , Desempenho Psicomotor/fisiologia , Estimulação Acústica , Adulto , Eletroencefalografia , Eletromiografia , Feminino , Humanos , Imaginação/fisiologia , Masculino , Estimulação Luminosa , Adulto Jovem
17.
Neuroimage ; 239: 118307, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34174389

RESUMO

Neural oscillations are fundamental mechanisms of the human brain that enable coordinated activity of different brain regions during perceptual and cognitive processes. A frontotemporal network generated by means of gamma oscillations and comprising the auditory cortex (AC) and the anterior cingulate cortex (ACC) has been shown to be involved in the cognitively demanding auditory information processing. This study aims to reveal patterns of functional and effective connectivity within this network in healthy subjects by means of simultaneously recorded electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). We simultaneously recorded EEG and fMRI in 28 healthy subjects during the performance of a cognitively demanding auditory choice reaction task. Connectivity between the ACC and AC was analysed employing EEG and fMRI connectivity measures. We found a significant BOLD signal correlation between the ACC and AC, a significant task-dependant increase of fMRI connectivity (gPPI) and a significant increase in functional coupling in the gamma frequency range between these regions (LPS), which was increased in top-down direction (granger analysis). EEG and fMRI connectivity measures were positively correlated. The results of these study point to a role of a top-down influence of the ACC on the AC executed by means of gamma synchronisation. The replication of fMRI connectivity patterns in simultaneously recorded EEG data and the correlation between connectivity measures from both domains found in our study show, that brain connectivity based on the synchronisation of gamma oscillations is mirrored in fMRI connectivity patterns.


Assuntos
Córtex Auditivo/diagnóstico por imagem , Percepção Auditiva/fisiologia , Conectoma , Sincronização de Fases em Eletroencefalografia , Lobo Frontal/diagnóstico por imagem , Raios gama , Giro do Cíngulo/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adulto , Córtex Auditivo/fisiologia , Eletroencefalografia , Sincronização de Fases em Eletroencefalografia/fisiologia , Feminino , Lobo Frontal/fisiologia , Giro do Cíngulo/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/fisiologia , Tálamo/fisiologia , Adulto Jovem
18.
J Sleep Res ; 30(3): e13170, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32865294

RESUMO

Parkinson's disease motor dysfunctions are associated with improperly organised neural oscillatory activity. The presence of such disruption at the early stages of the disease in which altered sleep is one of the main features could be a relevant predictive feature. Based on this, we aimed to investigate the neocortical synchronisation dynamics during slow-wave sleep (SWS) in the rotenone model of Parkinson's disease. After rotenone administration within the substantia nigra pars compacta, one group of male Wistar rats underwent sleep-wake recording. Considering the association between SWS oscillatory activity and memory consolidation, another group of rats underwent a memory test. The fine temporal structure of synchronisation dynamics was evaluated by a recently developed technique called first return map. We observed that rotenone administration decreased the time spent in SWS and altered the power spectrum within different frequency bands, whilst it increased the transition rate from a synchronised to desynchronised state. This neurotoxin also increased the probability of longer and decreased the probability of shorter desynchronisation events. At the same time, we observed impairment in object recognition memory. These findings depict an electrophysiological fingerprint represented by a disruption in the typical oscillatory activity within the neocortex at the early stages of Parkinson's disease, concomitant with a decrease in the time spent in SWS and impairment in recognition memory.


Assuntos
Eletroencefalografia/métodos , Inseticidas/uso terapêutico , Neocórtex/fisiopatologia , Doença de Parkinson/tratamento farmacológico , Rotenona/uso terapêutico , Sono de Ondas Lentas/fisiologia , Animais , Humanos , Inseticidas/farmacologia , Masculino , Doença de Parkinson/patologia , Ratos , Ratos Wistar , Rotenona/farmacologia
19.
Brain Cogn ; 148: 105677, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33486194

RESUMO

Neural oscillations and their association with brain states and cognitive functions have been object of extensive investigation over the last decades. Several electroencephalography (EEG) and magnetoencephalography (MEG) analysis approaches have been explored and oscillatory properties have been identified, in parallel with the technical and computational advancement. This review provides an up-to-date account of how EEG/MEG oscillations have contributed to the understanding of cognition. Methodological challenges, recent developments and translational potential, along with future research avenues, are discussed.


Assuntos
Eletroencefalografia , Magnetoencefalografia , Encéfalo , Mapeamento Encefálico , Cognição , Humanos
20.
Sensors (Basel) ; 21(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34770436

RESUMO

In many embedded systems, we face the problem of correlating signals characterising device operation (e.g., performance parameters, anomalies) with events describing internal device activities. This leads to the investigation of two types of data: time series, representing signal periodic samples in a background of noise, and sporadic event logs. The correlation process must take into account clock inconsistencies between the data acquisition and monitored devices, which provide time series signals and event logs, respectively. The idea of the presented solution is to classify event logs based on the introduced similarity metric and deriving their distribution in time. The identified event log sequences are matched with time intervals corresponding to specified sample patterns (objects) in the registered signal time series. The matching (correlation) process involves iterative time offset adjustment. The paper presents original algorithms to investigate correlation problems using the object-oriented data models corresponding to two monitoring sources. The effectiveness of this approach has been verified in power consumption analysis using real data collected from the developed Holter device. It is quite universal and can be easily adapted to other device optimisation problems.


Assuntos
Algoritmos
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