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Sensitivity suppression during attention shifts.

The brain possesses the remarkable ability to suppress undesirable signals generated by our own actions to ensure accurate perception, like the suppression of retinal motion signals during rapid eye movements, known as saccadic suppression. Attention, often referred to as the "mind's eye," undergoes rapid and frequent shifts, often occurring in the absence of explicit motor actions. Is visual processing similarly suppressed during attention shifts? In this study, we employed pupillometry and magnetoencephalography (MEG) to assess visual sensitivity across different attentional states. Our resu…

OPM-MEG в множестве склерозов: Доказательство принципа и эффект натуралистической осанки.

Множественный склероз (MS) — обычное неврологическое расстройство, при котором повреждение миэлина влияет на нейронную сигнализацию. Магнитоэнцефалография (MEG - измерение магнитных полей, генерируемых нейронными течениями) предлагает метрики функции мозга, которые непосредственно связаны с электрофизиологической сигнализацией, что делает ее ценным инструментом для изучения того, как аномальная функция соотносится с симптомами MS. Однако обычное МГЭ требует, чтобы участники сидели или сидели с ограниченным движением головы и тела. Это затрудняет измерение функции мозга, одновременно призывая п

Совпадение в аннотации оригинала
Multiple Sclerosis (MS) is a common neurological disorder in which myelin damage affects neuronal signalling. Magnetoencephalography (MEG - the measurement of magnetic fields generated by neuronal currents) offers metrics of brain function that relate directly to electrophysiological signalling, making it a valuable tool for exploring how abnormal function r…

Pre-frontal cortex guides dimension-reducing transformations in the occipito-ventral pathway for categorization behaviors.

To interpret our surroundings, the brain uses a visual categorization process. Current theories and models suggest that this process comprises a hierarchy of different computations that transforms complex, high-dimensional inputs into lower-dimensional representations (i.e., manifolds) in support of multiple categorization behaviors. Here, we tested this hypothesis by analyzing these transformations reflected in dynamic MEG source activity while individual participants actively categorized the same stimuli according to different tasks: face expression, face gender, pedestrian gender, and vehic

Subjective cognitive decline exhibits alterations of resting-state phase-amplitude coupling in precuneus.

OBJECTIVE: Subjective cognitive decline (SCD) is associated with increased risks for progressing to Alzheimer's disease (AD). This study aimed to investigate phase-amplitude coupling (PAC) in individuals with SCD and healthy controls (HCs) in the baseline year and determined the predictability of cognitive changes in the clinical follow-up. METHODS: Resting-state magnetoencephalographic signals in 29 HCs and 23 SCD subjects were recorded in the baseline year. The parahippocampal gyrus, posterior cingulate cortex and precuneus were selected as regions of interest (ROIs). Based on the grand-ave

Evaluation of changes in neural oscillation after bilateral capsulotomy in treatment refractory obsessive-compulsive disorder using magnetoencephalogram.

Bilateral thermal capsulotomy with magnetic resonance-guided focused ultrasound (MRgFUS-capsulotomy) is a promising treatment option for treatment-refractory obsessive-compulsive disorder (OCD). Herein, we investigated the effects of bilateral thermal capsulotomy with MRgFUS on neural oscillations in treatment-refractory OCD patients. Eight patients underwent resting-state MEG with repeated recordings before and 1 and 6 months after MRgFUS-capsulotomy, and the oscillatory power and phase coherence over the entire cortical sensor area were measured. After MRgFUS-capsulotomy, the high beta band

Tuning Minimum-Norm regularization parameters for optimal MEG connectivity estimation.

The accurate characterization of cortical functional connectivity from Magnetoencephalography (MEG) data remains a challenging problem due to the subjective nature of the analysis, which requires several decisions at each step of the analysis pipeline, such as the choice of a source estimation algorithm, a connectivity metric and a cortical parcellation, to name but a few. Recent studies have emphasized the importance of selecting the regularization parameter in minimum norm estimates with caution, as variations in its value can result in significant differences in connectivity estimates. In p…

Neural circuits underpinning face tuning in male depression.

Reading bodies and faces is essential for efficient social interactions, though it may be thought-provoking for individuals with depression. Yet aberrations in the face sensitivity and underwriting neural circuits are not well understood, in particular, in male depression. Here, we use cutting-edge analyses of time course and dynamic topography of gamma oscillatory neuromagnetic cortical activity during administration of a task with Arcimboldo-like images. No difference in face tuning was found between individuals with depression and their neurotypical peers. Furthermore, this behavioral outco

Disturbances in primary visual processing as a function of healthy aging.

For decades, visual entrainment paradigms have been widely used to investigate basic visual processing in healthy individuals and those with … ase (AD). In the current study, we examined visual entrainment in eighty healthy aging adults using magnetoencephalography (MEG) and a 15 Hz entrainment paradigm, while controlling for age-related cortical thinning. MEG data were imaged using a time-frequency resolved beamformer and peak voxel time series were extracted to quantify the oscillatory dynamics underlying th …

Autism Detection in Children using Common Spatial Patterns of MEG Signals.

Autism exhibits a wide range of developmental disabilities and is associated with aberrant anatomical and functional neural patterns. To detect autism in young children (4-7 years) in an automatic and non-invasive fashion, we have recorded magnetoencephalogram (MEG) signals from 30 autistic and 30 age-matched typically developing (TD) children. We have used a machine learning classification framework with common spatial pattern (CSP)-based logarithmic band power (LBP) features. When comparing the LBP feature to the conventional logarithmic variance (LV) spatial pattern, CSP + LBP (92.77%) has

Persistent activity in human parietal cortex mediates perceptual choice repetition bias.

Humans and other animals tend to repeat or alternate their previous choices, even when judging sensory stimuli presented in a random sequence. It is unclear if and how sensory, associative, and motor cortical circuits produce these idiosyncratic behavioral biases. Here, we combined behavioral modeling of a visual perceptual decision with magnetoencephalographic (MEG) analyses of neural dynamics, across multiple regions of the human cerebral cortex. We identified distinct history-dependent neural signals in motor and posterior parietal cortex. Gamma-band activity in parietal cortex tracked prev

Insights from Magnetic Evoked Field Analysis in Patients with Wilson's Disease.

AIMS: To study the latency, amplitude, and source localization of magnetic evoked field (MEF) responses to visual, auditory, and somatosensory stimuli in Wilson's disease (WD) using magnetoencephalography (MEG) and compare it with "Работает" controls, and correlate the observations with disease severity and brain MRI. METHODS: MEF of 28 patients with neurological WD (age: 22.82 ± 5.8 years; M:F = 12:16) and 21 matched controls (age: 25.0 ± 4.6 years; M:F = 10:11) were recorded using MEG. Source localization was performed using standard models on the components of M100, M20, and M100 for visual…

Epigenetic aging is associated with aberrant neural oscillatory dynamics serving visuospatial processing in people with HIV.

BACKGROUND: Despite effective antiretroviral therapy, cognitive impairment and other aging-related comorbidities are more prevalent in peopl … ood draw to determine biological age via DNA methylation, and a visuospatial processing task during magnetoencephalography (MEG). Our analyses focused on the relationship between biological age and oscillatory theta (4-8 Hz) and alpha (10 - 16 Hz) activity among PWH (n=65) and seronegative controls (n = 69). RESULTS: PWH had significantly elevated biological age when c …

Visuospatial alpha and gamma oscillations scale with the severity of cognitive dysfunction in patients on the Alzheimer's disease spectrum.

BACKGROUND: Entrainment of neural oscillations in occipital cortices by external rhythmic visual stimuli has been proposed as a novel therapy for patients with Alzheimer's disease (AD). Despite this increased interest in visual neural oscillations in AD, little is known regarding their role in AD-related cognitive impairment and in particular during visuospatial processing. METHODS: We used source-imaged magnetoencephalography (MEG) and an established visuospatial processing task to elicit multi-spectral neuronal responses in 35 biomarker-confirmed patients on the AD spectrum and 20 biomarker…

The impact of mild-to-severe hearing loss on the neural dynamics serving verbal working memory processing in children.

Children with hearing loss (CHL) exhibit delays in language function relative to children with normal hearing (CNH). However, evidence on wh … this end, participants with and without hearing loss performed a verbal working memory task during magnetoencephalography. Neural oscillatory responses associated with working memory encoding and maintenance were imaged separately, and these responses were statistically evaluated between CHL and CNH. While CHL performed as well on the task as CNH, CHL exhibited signifi …

Dysfunctional frontal activation of mismatch negativity in panic disorder: A magnetoencephalographic study.

BACKGROUND: Mismatch negativity (MMN) or its magnetic counterpart (MMNm) is a neurophysiological signal to reflect the automatic change-detection ability. However, MMN studies in patients with panic disorder (PD) showed contrasting results using electroencephalographic (EEG) recordings. The present study attempted to overcome the limitations of EEG methodology by means of a whole-head magnetoencephalography (MEG) combined with the depth-weighted minimum norm estimate method to conduct an in-depth investigation on the MMNm at the cortical level in patients with PD. METHODS: We recruited 22 hea…

ZapLine: A simple and effective method to remove power line artifacts.

Power line artifacts are the bane of animal and human electrophysiology. A number of methods are available to help attenuate or eliminate th … in clean data. This method is applicable to multichannel data such as electroencephalography (EEG), magnetoencephalography (MEG), or multichannel local field potentials (LFP). I briefly review past methods, pointing out their drawbacks, describe the new method, and evaluate the outcome using synthetic and real data.

Decoding Speech from Single Trial MEG Signals Using Convolutional Neural Networks and Transfer Learning.

Decoding speech directly from the brain has the potential for the development of the next generation, more efficient brain computer interfaces (BCIs) to assist in the communication of patients with locked-in syndrome (fully paralyzed but aware). In this study, we have explored the spectral and temporal features of the magnetoencephalography (MEG) signals and trained those features with convolutional neural networks (CNN) for the classification of neural signals corresponding to phrases. Experimental results demonstrated the effectiveness of CNNs in decoding speech during perception, imaginatio…

Predicting depression based on dynamic regional connectivity: a windowed Granger causality analysis of MEG recordings.

Abnormal inter-regional causalities can be mapped for the objective diagnosis of various diseases. These inter-regional connectivities are usually calculated over an entire scan and used to characterize the stationary strength of the connections. However, the connectivity within networks may undergo substantial changes during a scan. In this study, we developed an objective depression recognition approach using the dynamic regional interactions that occur in response to sad facial stimuli. The whole time-period magnetoencephalography (MEG) signals from the visual cortex, amygdala, anterior cin…

[Techniques for the functional evaluation of neurodevelopmental disorders].

AIM: To review the evaluation of neuropsychological functions by using non-invasive functional neuroimaging methods. DEVELOPMENT: Non-invasive functional neuroimaging methods can be sorted into two broad categories: the first includes those that make use of electromagnetic techniques, such as event-related potentials and magnetoencephalography (MEG), and the second consists of those involving haemodynamic techniques, such as positron emission tomography and functional magnetic resonance imaging. These methods have been employed in particular to evaluate the following functions: attention, per…

Language at a glance: How our brains grasp linguistic structure from parallel visual input.

Human brains grasp the gists of visual scenes from a single glance, but to what extent is this possible for language? While we typically think of language in terms of sequential speech, our everyday experience involves numerous rapidly flashing written notifications, which we understand instantly. What do our brains detect in the first few hundred milliseconds after seeing such a stimulus? We flashed short sentences during magnetoencephalography measurement, revealing sentence-sensitive neural activity in left temporal cortex within 130 milliseconds. These signals emerged for subject-verb-obje…