scholarly journals The Spatial Reach of Neuronal Coherence and Spike-field Coupling across the Human Neocortex

2021 ◽  
Author(s):  
John Myers ◽  
Elliot H Smith ◽  
Marcin Leszczynski ◽  
James O'Sullivan ◽  
Guy M McKhann ◽  
...  
Keyword(s):  
Phase Synchronization ◽  
Microelectrode Arrays ◽  
Brain Regions ◽  
Spike Timing ◽  
Cognitive Tasks ◽  
Field Potentials ◽  
Field Coupling ◽  
Power Law Decay ◽  
Spectral Frequency ◽  
Neuronal Coherence

Neuronal coherence is thought to be a fundamental mechanism of communication in the brain, where synchronized field potentials coordinate synaptic and spiking events to support plasticity and learning. Although the spread of field potentials has garnered great interest, little is known about the spatial reach of phase synchronization, or neuronal coherence. Functional connectivity between different brain regions is known to occur across long distances, but the locality of coherence within a brain region is understudied. Here we used simultaneous recordings from electrocorticography (ECoG) grids and high-density microelectrode arrays to estimate the spatial reach of neuronal coherence and spike-field coherence (SFC) across frontal, temporal, and occipital cortices during cognitive tasks in humans. We observed the strongest coherence within a 2-3 cm distance from the microelectrode arrays, potentially defining an effective range for local communication. This range was relatively consistent across brain regions, spectral frequencies, and cognitive tasks. The magnitude of coherence showed power law decay with increasing distance from the microelectrode arrays, where the highest coherence occurred between ECoG contacts, followed by coherence between ECoG and deep cortical LFP, and then SFC (i.e., ECoG > LFP > SFC). The spectral frequency of coherence also affected its magnitude. Alpha coherence (8-14 Hz) was generally higher than other frequencies for signals nearest the microelectrode arrays, whereas delta coherence (1-3 Hz) was higher for signals that were farther away. Action potentials in all brain regions were most coherent with the phase of alpha oscillations, which suggests that alpha waves could play a larger, more spatially local role in spike timing than other frequencies. These findings provide a deeper understanding of the spatial and spectral dynamics of neuronal coherence, further advancing knowledge about how activity propagates across the human brain.

scholarly journals Long-range phase synchronization of high-frequency oscillations in human cortex

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
G. Arnulfo ◽  
S. H. Wang ◽  
V. Myrov ◽  
B. Toselli ◽  
J. Hirvonen ◽  
...  
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
Phase Synchronization ◽  
Brain Activity ◽  
Brain Regions ◽  
Spike Timing ◽  
Human Cortex ◽  
Neuronal Communication ◽  
High Frequency Oscillations ◽  
Connectivity Patterns

Abstract Inter-areal synchronization of neuronal oscillations at frequencies below ~100 Hz is a pervasive feature of neuronal activity and is thought to regulate communication in neuronal circuits. In contrast, faster activities and oscillations have been considered to be largely local-circuit-level phenomena without large-scale synchronization between brain regions. We show, using human intracerebral recordings, that 100–400 Hz high-frequency oscillations (HFOs) may be synchronized between widely distributed brain regions. HFO synchronization expresses individual frequency peaks and exhibits reliable connectivity patterns that show stable community structuring. HFO synchronization is also characterized by a laminar profile opposite to that of lower frequencies. Importantly, HFO synchronization is both transiently enhanced and suppressed in separate frequency bands during a response-inhibition task. These findings show that HFO synchronization constitutes a functionally significant form of neuronal spike-timing relationships in brain activity and thus a mesoscopic indication of neuronal communication per se.

scholarly journals Travelling spindles create necessary conditions for spike-timing-dependent plasticity in humans

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Charles W. Dickey ◽  
Anna Sargsyan ◽  
Joseph R. Madsen ◽  
Emad N. Eskandar ◽  
Sydney S. Cash ◽  
...  
Keyword(s):  
Eye Movement ◽  
Necessary Conditions ◽  
Microelectrode Arrays ◽  
Spike Timing ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Field Potentials ◽  
Spike Timing Dependent Plasticity ◽  
Dependent Plasticity ◽  
Cell Firing

AbstractSleep spindles facilitate memory consolidation in the cortex during mammalian non-rapid eye movement sleep. In rodents, phase-locked firing during spindles may facilitate spike-timing-dependent plasticity by grouping pre-then-post-synaptic cell firing within ~25 ms. Currently, microphysiological evidence in humans for conditions conducive for spike-timing-dependent plasticity during spindles is absent. Here, we analyze field potentials and unit firing from middle/upper layers during spindles from 10 × 10 microelectrode arrays at 400 μm pitch in humans. We report strong tonic and phase-locked increases in firing and co-firing within 25 ms during spindles, especially those co-occurring with down-to-upstate transitions. Co-firing, spindle co-occurrence, and spindle coherence are greatest within ~2 mm, and high co-firing of units on different contacts depends on high spindle coherence between those contacts. Spindles propagate at ~0.28 m/s in distinct patterns, with correlated cell co-firing sequences. Spindles hence organize spatiotemporal patterns of neuronal co-firing in ways that may provide pre-conditions for plasticity during non-rapid eye movement sleep.

scholarly journals INITIAL SURGICAL EXPERIENCE WITH A DENSE CORTICAL MICROARRAY IN EPILEPTIC PATIENTS UNDERGOING CRANIOTOMY FOR SUBDURAL ELECTRODE IMPLANTATION

Neurosurgery ◽  
2009 ◽  
Vol 64 (3) ◽  
pp. 540-545 ◽  
Author(s):  
Allen Waziri ◽  
Catherine A. Schevon ◽  
Joshua Cappell ◽  
Ronald G. Emerson ◽  
Guy M. McKhann ◽  
...  
Keyword(s):  
Local Field ◽  
Single Unit ◽  
Microelectrode Array ◽  
Tissue Injury ◽  
Local Field Potentials ◽  
Microelectrode Arrays ◽  
Field Potentials ◽  
Surgical Experience ◽  
Electrode Implantation ◽  
Subdural Electrode

Abstract OBJECTIVE Detailed investigations of cortical physiology require the ability to record brain electrical activity at a submillimeter scale. Standard intracranial electrodes result in significant averaging of potentials generated by large numbers of neurons. In contrast, microelectrode arrays allow for recording of local field potentials and single-unit activity. We describe our initial surgical experience with the NeuroPort microelectrode array (Cyberkinetics Neurotechnology Systems, Inc., Salt Lake City, UT) in a series of patients undergoing subdural electrode implantation for epilepsy monitoring. METHODS Seven patients were implanted with and underwent semichronic recording from the NeuroPort array during standard subdural electrode monitoring for epilepsy. The electrode was placed according to company specifications in putative noneloquent epileptogenic cortex. After the monitoring period, microelectrode arrays were removed during explantation of subdural electrodes and resection of epileptogenic tissue. RESULTS Successful implantation of the microelectrode array was achieved in all patients, with minor operative difficulties. Robust and durable local field potentials and single-unit recordings were obtained from all implanted individuals. Implantation times ranged from 3 to 28 days; histological analysis of implanted tissue demonstrated no significant tissue injury or inflammatory response. There were no neurological complications or infections associated with electrode implantation or prolonged monitoring. Two patients developed postresection issues with wound healing at the site of scalp egress, with 1 requiring operative wound revision. CONCLUSION Our experience demonstrates that semichronic microelectroencephalographic recording can be safely and effectively achieved using the NeuroPort microarray. Although significant tissue injury, infection, or cerebrospinal fluid leak was not encountered, the large profile of the connection pedestal resulted in suboptimal wound closure and healing in several patients. We predict that this problem will be easily addressed in second-generation devices.

scholarly journals Prefrontal cortical plasticity during learning of cognitive tasks

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Hua Tang ◽  
Mitchell R. Riley ◽  
Balbir Singh ◽  
Xue-Lian Qi ◽  
David T. Blake ◽  
...  
Keyword(s):  
Neural Activity ◽  
Cortical Plasticity ◽  
Cortical Activity ◽  
Phase Changes ◽  
Cognitive Tasks ◽  
Training Phase ◽  
Field Potentials ◽  
Electrode Arrays ◽  
Control Task ◽  
Prefrontal Cortical

AbstractTraining in working memory tasks is associated with lasting changes in prefrontal cortical activity. To assess the neural activity changes induced by training, we recorded single units, multi-unit activity (MUA) and local field potentials (LFP) with chronic electrode arrays implanted in the prefrontal cortex of two monkeys, throughout the period they were trained to perform cognitive tasks. Mastering different task phases was associated with distinct changes in neural activity, which included recruitment of larger numbers of neurons, increases or decreases of their firing rate, changes in the correlation structure between neurons, and redistribution of power across LFP frequency bands. In every training phase, changes induced by the actively learned task were also observed in a control task, which remained the same across the training period. Our results reveal how learning to perform cognitive tasks induces plasticity of prefrontal cortical activity, and how activity changes may generalize between tasks.

scholarly journals The effects of cannabis use on salience attribution: a systematic review

2016 ◽  
Vol 30 (1) ◽  
pp. 43-57 ◽  
Author(s):  
Surapi Bhairavi Wijayendran ◽  
Aisling O’Neill ◽  
Sagnik Bhattacharyya
Keyword(s):  
Brain Regions ◽  
Cannabis Use ◽  
Cognitive Tasks ◽  
Indirect Measures ◽  
Neural Processes ◽  
Aberrant Salience ◽  
And Performance ◽  
The Relationship ◽  
Chronic Use

ObjectiveThe relationship between cannabis use and the onset of psychosis is well established. Aberrant salience processing is widely thought to underpin many of these symptoms. Literature explicitly investigating the relationship between aberrant salience processing and cannabis use is scarce; with those few studies finding that acute tetrahydrocannabinol (THC) administration (the main psychoactive component of cannabis) can result in abnormal salience processing in healthy cohorts, mirroring that observed in psychosis. Nevertheless, the extent of and mechanisms through which cannabis has a modulatory effect on aberrant salience, following both acute and chronic use, remain unclear.MethodsHere, we systematically review recent findings on the effects of cannabis use – either through acute THC administration or in chronic users – on brain regions associated with salience processing (through functional MRI data); and performance in cognitive tasks that could be used as either direct or indirect measures of salience processing. We identified 13 studies either directly or indirectly exploring salience processing. Three types of salience were identified and discussed – incentive/motivational, emotional/affective, and attentional salience.ResultsThe results demonstrated an impairment of immediate salience processing, following acute THC administration. Amongst the long-term cannabis users, normal salience performance appeared to be underpinned by abnormal neural processes.ConclusionsOverall, the lack of research specifically exploring the effects of cannabis use on salience processing, weaken any conclusions drawn. Additional research explicitly focussed on salience processing and cannabis use is required to advance our understanding of the neurocognitive mechanisms underlying the association between cannabis use and development of psychosis.

scholarly journals Development of Network Synchronization Predicts Language Abilities

2016 ◽  
Vol 28 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Sam M. Doesburg ◽  
Keriann Tingling ◽  
Matt J. MacDonald ◽  
Elizabeth W. Pang
Keyword(s):  
Large Scale ◽  
Phase Synchronization ◽  
Age Groups ◽  
Brain Regions ◽  
Childhood And Adolescence ◽  
Network Synchronization ◽  
Language Abilities ◽  
Generation Task ◽  
Development Of Language ◽  
Verb Generation

Synchronization of oscillations among brain areas is understood to mediate network communication supporting cognition, perception, and language. How task-dependent synchronization during word production develops throughout childhood and adolescence, as well as how such network coherence is related to the development of language abilities, remains poorly understood. To address this, we recorded magnetoencephalography while 73 participants aged 4–18 years performed a verb generation task. Atlas-guided source reconstruction was performed, and phase synchronization among regions was calculated. Task-dependent increases in synchronization were observed in the theta, alpha, and beta frequency ranges, and network synchronization differences were observed between age groups. Task-dependent synchronization was strongest in the theta band, as were differences between age groups. Network topologies were calculated for brain regions associated with verb generation and were significantly associated with both age and language abilities. These findings establish the maturational trajectory of network synchronization underlying expressive language abilities throughout childhood and adolescence and provide the first evidence for an association between large-scale neurophysiological network synchronization and individual differences in the development of language abilities.

scholarly journals Modules in connectomes of phase-synchronization comprise anatomically contiguous, spatially related regions

2021 ◽  
Author(s):  
N. Williams ◽  
S. H. Wang ◽  
G. Arnulfo ◽  
L. Nobili ◽  
S. Palva ◽  
...  
Keyword(s):  
Phase Synchronization ◽  
Spatial Scales ◽  
Brain Regions ◽  
Detection Methods ◽  
Modular Organization ◽  
Consensus Clustering ◽  
Volume Conduction ◽  
Functional Connections ◽  
Gamma Frequency ◽  
Cortical Regions

Modules in brain connectomes are essential to balancing the functional segregation and integration crucial to brain operation. Connectomes are the set of structural or functional connections between each pair of brain regions. Non-invasive methodologies, Electroencephalography (EEG) and Magnetoencephalography (MEG), have been used to identify modules in connectomes of phase-synchronization, but have been compromised by spurious phase-synchronization due to EEG volume conduction or MEG field spread. In this study, we used invasive, intracerebral recordings with stereo-electroencephalography (SEEG, N = 67), to identify modules in connectomes of phase-synchronization. To do this, we used submillimetre localization of SEEG contacts and closest-white-matter referencing, to generate group-level connectomes of phase-synchronization minimally affected by volume conduction. Then, we employed community detection methods together with a novel consensus clustering approach, to identify modules in connectomes of phase-synchronization. The connectomes of phase-synchronization possessed significant modular organization at multiple spatial scales, from 3-320 Hz. These identified modules were highly similar within neurophysiologically meaningful frequency bands. Modules up to the high-gamma frequency band comprised only anatomically contiguous regions, unlike modules identified with functional Magnetic Resonance Imaging (fMRI). Strikingly, the identified modules comprised cortical regions involved in shared repertoires of cognitive functions including vision, language and attention. These results demonstrate the viability of combining SEEG with advanced methods, to identify modules in connectomes of phase-synchronization. The modules correspond to brain systems with specific functional roles in perceptual, cognitive, and motor processing.

scholarly journals In-phase and in-antiphase connectivity in EEG

2021 ◽  
Author(s):  
Christian O'Reilly ◽  
John D Lewis ◽  
Rebecca J Theilmann ◽  
Mayada Elsabbagh ◽  
Jeanne Townsend
Keyword(s):  
Functional Connectivity ◽  
Local Field ◽  
Significant Proportion ◽  
Brain Regions ◽  
Field Potentials ◽  
Volume Conduction ◽  
Confounding Effect ◽  
Neuronal Communication ◽  
Neural Communication ◽  
Eeg Connectivity

Zero-lag synchrony is generally discarded from functional connectivity studies to eliminate the confounding effect of volume conduction. Demonstrating genuine and significant unlagged synchronization between distant brain regions would indicate that most electroencephalography (EEG) connectivity studies neglect an important mechanism for neuronal communication. We previously demonstrated that local field potentials recorded intracranially tend to synchronize with no lag between homotopic brain regions. This synchrony occurs most frequently in antiphase, potentially supporting corpus callosal inhibition and interhemispheric rivalry. We are now extending our investigation to EEG. By comparing the coherency in a recorded and a surrogate dataset, we confirm the presence of a significant proportion of genuine zero-lag synchrony unlikely to be due to volume conduction or to recording reference artifacts. These results stress the necessity for integrating zero-lag synchrony in our understanding of neural communication and for disentangling volume conduction and zero-lag synchrony when estimating EEG sources and their functional connectivity.

scholarly journals Grasp-Squeeze Adaptation to Changes in Object Compliance Leads to Dynamic Beta-Band Communication Between Primary Somatosensory and Motor Cortices

2022 ◽  
Author(s):  
HUY CU ◽  
LAURIE LYNCH ◽  
KEVIN HUANG ◽  
WILSON TRUCCOLO ◽  
ARTO NURMIKKO
Keyword(s):  
Steady State ◽  
Nonhuman Primates ◽  
Microelectrode Arrays ◽  
Field Potentials ◽  
Target Level ◽  
Beta Band ◽  
Cortical Areas ◽  
Short Period ◽  
The Subject ◽  
The Brain

Abstract In asking the question of how the brain adapts to changes in the softness of manipulated objects, we studied dynamic communication between the primary sensory and motor cortical areas when nonhuman primates grasp and squeeze an elastically deformable manipulandum to attain an instructed force level. We focused on local field potentials recorded from S1 and M1 via intracortical microelectrode arrays. We computed nonparametric spectral Granger Causality to assess directed cortico-cortical interactions between these two areas. We demonstrate that the time-causal relationship between M1 and S1 is bidirectional in the beta-band (15-30Hz) and that this interareal communication develops dynamically as the subjects adjust the force of hand squeeze to reach the target level. In particular, the directed interaction is strongest when subjects are focused on maintaining the instructed force of hand squeeze in a steady state for several seconds. When the manipulandum’s compliance is abruptly changed, beta-band interareal communication is interrupted for a short period (~ 1 second) and then is re-established once the subject has reached a new steady state. These results suggest that transient beta oscillations can provide a communication subspace for dynamic cortico-cortical S1-M1 interactions during maintenance of steady sensorimotor states.

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