Spatiotemporal brain hierarchies of auditory memory recognition and predictive coding

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Май 21, 2024

Abstract Our brain is constantly extracting, predicting, and recognising key spatiotemporal features of the physical world in order to survive. While neural processing visuospatial patterns has been extensively studied, hierarchical mechanisms underlying conscious recognition auditory sequences associated prediction errors remain elusive. Using magnetoencephalography (MEG), we describe functioning 83 participants during previously memorised musical systematic variations. The results show feedforward connections originating from cortices, extending hippocampus, anterior cingulate gyrus, medial gyrus. Simultaneously, observe backward operating opposite direction. Throughout sequences, hippocampus gyrus maintain same level, except for final tone, where assumes top position within hierarchy. evoked responses variations engage network but systematically differ terms temporal dynamics, strength, polarity. Furthermore, induced-response analysis shows that alpha beta power stronger variations, while gamma enhanced sequences. This study expands on predictive coding theory by providing quantitative evidence memory

Язык: Английский

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Validating MEG estimated resting state connectome with intracranial EEG

Network Neuroscience, Год журнала: 2025, Номер 9(1), С. 421 - 446

Опубликована: Янв. 1, 2025

Magnetoencephalography (MEG) is widely used for studying resting-state brain connectivity. However, MEG source imaging ill posed and has limited spatial resolution. This introduces source-leakage issues, making it challenging to interpret MEG-derived connectivity in resting states. To address this, we validated from 45 healthy participants using a normative intracranial EEG (iEEG) atlas. The inverse problem was solved the wavelet-maximum entropy on mean method. We computed four metrics: amplitude envelope correlation (AEC), orthogonalized AEC (OAEC), phase locking value (PLV), weighted-phase lag index (wPLI). compared between iEEG connectomes across standard canonical frequency bands. found moderate correlations PLV. when considering metrics that correct/remove zero-lag (OAEC/wPLI), decreased. exhibited higher with iEEG. suggest relevant patterns can be recovered MEG. since these are moderate/low, results should interpreted caution. Metrics correct show decreased correlations, highlighting trade-off; while may capture more due source-leakage, removing eliminate true connections.

Язык: Английский

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Excitation/Inhibition balance relates to cognitive function and gene expression in temporal lobe epilepsy: a high density EEG assessment with aperiodic exponent

Brain Communications, Год журнала: 2024, Номер 6(4)

Опубликована: Янв. 1, 2024

Patients with epilepsy are characterized by a dysregulation of excitation/inhibition balance (E/I). The assessment E/I may inform clinicians during the diagnosis and therapy management, even though it is rarely performed. An accessible measure brain represents clinically relevant feature. Here, we exploited exponent aperiodic component power spectrum electroencephalography (EEG) signal, as non-invasive cost-effective proxy balance. We recorded resting-state activity high-density EEG from 67 patients temporal lobe 35 controls. extracted fit source-reconstructed tested differences between Spearman's correlation was performed clinical variables (age onset, duration neuropsychology) cortical expression epilepsy-related genes derived Allen Human Brain Atlas. showed significantly larger exponent, corresponding to inhibition-directed balance, in bilateral frontal regions. Lower left entorhinal dorsolateral prefrontal cortices corresponded lower performance short-term verbal memory. Limited epilepsy, detected significant

Язык: Английский

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EEG/MEG source imaging of deep brain activity within the maximum entropy on the mean framework: Simulations and validation in epilepsy

Human Brain Mapping, Год журнала: 2024, Номер 45(10)

Опубликована: Июль 12, 2024

Abstract Electro/Magneto‐EncephaloGraphy (EEG/MEG) source imaging (EMSI) of epileptic activity from deep generators is often challenging due to the higher sensitivity EEG/MEG superficial regions and spatial configuration subcortical structures. We previously demonstrated ability coherent Maximum Entropy on Mean (cMEM) method accurately localize cortical their extent. Here, we propose a depth‐weighted adaptation cMEM more accurately. These methods were evaluated using realistic MEG/high‐density EEG (HD‐EEG) simulations actual MEG/HD‐EEG recordings patients with focal epilepsy. incorporated depth‐weighting within MEM framework compensate for its preference generators. also included mesh both hippocampi, as an additional structure in model. generated 5400 interictal discharges MEG HD‐EEG involving wide range extents signal‐to‐noise ratio (SNR) levels, before investigating EMSI clinical 16 14 patients. Clinical marked by visual inspection. applied three methods: cMEM, minimum norm estimate (MNE). The ground truth was defined true simulated generator or drawn region based information available For sources, improved localization when compared MNE, whereas did not deteriorate accuracy regions. patients' data, observed improvement especially mesial temporal epilepsy, which failed reconstruct initial hippocampus. Depth weighting crucial (gradiometers) than HD‐EEG. Similar findings found considering depth wavelet extension MEM. In conclusion, sources without minimal deterioration sources. This extensive epilepsy

Язык: Английский

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Normative brain mapping using scalp EEG and potential clinical application

Scientific Reports, Год журнала: 2023, Номер 13(1)

Опубликована: Авг. 18, 2023

Abstract A normative electrographic activity map could be a powerful resource to understand normal brain function and identify abnormal activity. Here, we present using scalp EEG in terms of relative band power. In this exploratory study investigate its temporal stability, similarity other imaging modalities, explore potential clinical application. We constructed maps dynamics from 17 healthy controls source-localised resting-state recordings. then correlated these with those acquired MEG intracranial their similarity. Lastly, use the lateralise regions epilepsy. Spatial patterns powers were broadly consistent previous literature stable across Scalp most similar modalities alpha band, relatively bands. Towards application epilepsy, found ipsilateral epileptogenic hemisphere. power are spatially time, keeping results. Normative mapping is feasible may potentially clinically useful Future studies larger sample sizes high-density now required for validation.

Язык: Английский

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The Use of Magnetoencephalography in the Diagnosis and Monitoring of Mild Traumatic Brain Injuries and Post-Concussion Syndrome

Brain Sciences, Год журнала: 2025, Номер 15(2), С. 154 - 154

Опубликована: Фев. 4, 2025

Background/Objectives: The main objective of this systematic review was to explore the role magnetoencephalography (MEG) in diagnosis, assessment, and monitoring mild traumatic brain injury (mTBI) post-concussion syndrome (PCS). We aimed evaluate potential some MEG biomarkers detecting subtle abnormalities often missed by conventional imaging techniques. Methods: A conducted using 25 studies that administered examine mTBI PCS patients. quality assessed based on selection, comparability, outcomes. Studies were analyzed for their methodology, evaluated parameters, clinical implications diagnosis. Results: detected abnormal oscillations, including increased delta, theta, gamma waves disruptions functional connectivity, particularly default mode frontoparietal networks patients suffering from mTBI. consistently revealed even when structural normal. use recovery showed significant reductions slow-wave activity corresponding improvements. Machine learning algorithms applied data demonstrated high sensitivity specificity distinguishing healthy controls predicting Conclusions: provides a valuable diagnostic prognostic tool identifying neurophysiological abnormalities. temporal resolution ability assess make promising complement imaging. Future research should focus integrating with other neuroimaging modalities standardizing protocols use.

Язык: Английский

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NIRSTORM: a Brainstorm extension dedicated to functional near-infrared spectroscopy data analysis, advanced 3D reconstructions, and optimal probe design

Neurophotonics, Год журнала: 2025, Номер 12(02)

Опубликована: Май 15, 2025

Understanding the brain's complex functions requires multimodal approaches that combine data from various neuroimaging techniques. Functional near-infrared spectroscopy (fNIRS) offers valuable insights into hemodynamic responses, complementing other modalities such as electroencephalography (EEG), magnetoencephalography (MEG), and magnetic resonance imaging. However, there is a lack of comprehensive accessible toolboxes able to integrate fNIRS advanced analyses with modalities. NIRSTORM addresses this gap by offering unified platform for analysis. aims provide user-friendly environment analysis while supporting entire pipeline, experiment planning reconstruction fluctuations on cortex. Developed in MATLAB®, operates Brainstorm plugin, enhancing Brainstorm's capabilities analyzing data. widely used, GUI-based software originally designed statistical source imaging EEG MEG supports conventional preprocessing introducing new features optimal montage optode placement maximum entropy mean (MEM) reconstructing cortical surface. As an open-access extends functionality fNIRS, bridging between EEG/MEG analyses.

Язык: Английский

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Beyond Stereo-EEG: Is It Worth Combining Stereo-EEG With Other Diagnostic Methods?

Journal of Clinical Neurophysiology, Год журнала: 2024, Номер 41(5), С. 444 - 449

Опубликована: Июнь 25, 2024

Summary: Stereo-EEG is a widely used method to improve the diagnostic precision of presurgical workup in patients with refractory epilepsy. Its ability detect epileptic activity and identify networks largely depends on chosen implantation strategy. Even an ideal situation, electrodes record generated <10% brain contacts only from tissue their immediate proximity. In this article, authors discuss how recording stereo-EEG simultaneously other methods can its value clinical research settings. It help overcome limited spatial coverage intracranial better understand sources activity. Simultaneous scalp EEG most available method, often large networks, seizure propagation, occurring contralateral hemisphere. magnetoencephalography allows for more precise source localization identification deep outside coverage. Finally, simultaneous functional MRI highlight metabolic changes following widespread network associated interictal This overview highlights advantages methodological challenges all these methods. Clinical use applications are presented each approach.

Язык: Английский

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BROADband brain Network Estimation via Source Separation (BROAD-NESS)

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Окт. 31, 2024

ABSTRACT This study presents BROADband brain Network Estimation via Source Separation (BROAD- NESS), a novel method tailored for event-related designs, leveraging magnetoencephalography’s (MEG) high temporal and spatial resolution to identify dynamic networks without predefined regions. By applying principal component analysis (PCA) source-reconstructed MEG data from 83 participants in long-term musical sequence recognition task, BROAD-NESS captured more effectively than traditional approaches, revealing two main that explained 88% of the variance. The first network, involving auditory cortices medial cingulate gyrus, was associated with continuous processing. second encompassing prefrontal hippocampal regions, inferior cortex, insula, linked memory, confirmed predictions prediction error With limited computational demands minimal assumptions, offers powerful tool studying dynamics, enhancing understanding memory-related sequences.

Язык: Английский

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Spatiotemporal brain hierarchies of auditory memory recognition and predictive coding

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2022, Номер unknown

Опубликована: Ноя. 21, 2022

Abstract Our brain is constantly extracting, predicting, and recognising key spatiotemporal features of the physical world in order to survive. While neural processing visuospatial patterns has been extensively studied, hierarchical mechanisms underlying conscious recognition auditory sequences associated prediction errors remain elusive. Using magnetoencephalography (MEG), we studied functioning 83 participants during previously memorised musical systematic variations. The results showed feedforward connections originating from cortices, extending hippocampus, anterior cingulate gyrus, medial gyrus. Simultaneously, observed backward operating opposite direction. Throughout sequences, hippocampus gyrus maintained same level, except for final tone, where assumed top position within hierarchy. evoked responses variations engaged network but systematically differed terms temporal dynamics, strength, polarity. Furthermore, induced-response analysis that alpha beta power was stronger variations, while gamma enhanced sequences. This study expands on predictive coding theory by providing quantitative evidence memory

Язык: Английский

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