scholarly journals Dynamic relationships between spontaneous and evoked electrophysiological activity

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Soren Wainio-Theberge ◽  
Annemarie Wolff ◽  
Georg Northoff
Keyword(s):  
Neural Activity ◽  
Large Scale ◽  
Behavioral Outcomes ◽  
Low Frequencies ◽  
Scale Free ◽  
Non Invasive ◽  
Spontaneous Neural Activity ◽  
Electrophysiological Signals ◽  
Evoked Activity ◽  
Dynamic Relationships

AbstractSpontaneous neural activity fluctuations have been shown to influence trial-by-trial variation in perceptual, cognitive, and behavioral outcomes. However, the complex electrophysiological mechanisms by which these fluctuations shape stimulus-evoked neural activity remain largely to be explored. Employing a large-scale magnetoencephalographic dataset and an electroencephalographic replication dataset, we investigate the relationship between spontaneous and evoked neural activity across a range of electrophysiological variables. We observe that for high-frequency activity, high pre-stimulus amplitudes lead to greater evoked desynchronization, while for low frequencies, high pre-stimulus amplitudes induce larger degrees of event-related synchronization. We further decompose electrophysiological power into oscillatory and scale-free components, demonstrating different patterns of spontaneous-evoked correlation for each component. Finally, we find correlations between spontaneous and evoked time-domain electrophysiological signals. Overall, we demonstrate that the dynamics of multiple electrophysiological variables exhibit distinct relationships between their spontaneous and evoked activity, a result which carries implications for experimental design and analysis in non-invasive electrophysiology.

scholarly journals Bridging the gap – Spontaneous fluctuations shape stimulus-evoked spectral power

2020 ◽  
Author(s):  
Soren Wainio-Theberge ◽  
Annemarie Wolff ◽  
Georg Northoff
Keyword(s):  
Neural Activity ◽  
Large Scale ◽  
Spectral Power ◽  
Low Frequency ◽  
Positive Interaction ◽  
Scale Free ◽  
The Time Domain ◽  
Low Frequency Power ◽  
Spontaneous Fluctuations ◽  
Frequency Power

AbstractSpontaneous fluctuations of neural activity have been shown to influence trial-by-trial variation in perceptual, cognitive, and behavioural outcomes. This implies that these fluctuations affect stimulus-related neural processes, and hence should affect stimulus-evoked neural activity. However, the mechanisms by which spontaneous neural activity shapes stimulus-evoked neural activity have rarely been examined. Employing a large-scale magnetoencephalographic dataset, as well as an electroencephalographic replication dataset, we observed that for high-frequency power, high pre-stimulus activity leads to greater evoked desynchronization (negative interaction); in contrast, for low-frequency power, high pre-stimulus activity induces greater event-related synchronization (positive interaction). We show that both positive and negative interactions are manifest primarily in cortical oscillations, rather than scale-free activity, and can also be observed in the time domain. In summary, we demonstrate positive and negative spontaneous-evoked interaction in multiple electrophysiological processes; these mechanisms “bridge the gap” between spontaneous and evoked activity and provide novel insights into how spontaneous activity influences behaviour and cognition.

scholarly journals Temporal signatures of criticality in human cortical excitability as probed by early somatosensory responses

2019 ◽  
Author(s):  
T. Stephani ◽  
G. Waterstraat ◽  
S. Haufe ◽  
G. Curio ◽  
A. Villringer ◽  
...  
Keyword(s):  
Neural Networks ◽  
Neural Activity ◽  
Critical State ◽  
Cortical Excitability ◽  
Temporal Organization ◽  
Neural Responses ◽  
Scale Free ◽  
Spatio Temporal ◽  
Evoked Activity ◽  
The Impact

AbstractBrain responses vary considerably from moment to moment, even to identical sensory stimuli. This has been attributed to changes in instantaneous neuronal states determining the system’s excitability. Yet the spatio-temporal organization of these dynamics remains poorly understood. Here we test whether variability in stimulus-evoked activity can be interpreted within the framework of criticality, which postulates dynamics of neural systems to be tuned towards the phase transition between stability and instability as is reflected in scale-free fluctuations in spontaneous neural activity. Using a novel non-invasive approach in 33 male participants, we tracked instantaneous cortical excitability by inferring the magnitude of excitatory post-synaptic currents from the N20 component of the somatosensory evoked potential. Fluctuations of cortical excitability demonstrated long-range temporal dependencies decaying according to a power law across trials – a hallmark of systems at critical states. As these dynamics covaried with changes in pre-stimulus oscillatory activity in the alpha band (8–13 Hz), we establish a mechanistic link between ongoing and evoked activity through cortical excitability and argue that the co-emergence of common temporal power laws may indeed originate from neural networks poised close to a critical state. In contrast, no signatures of criticality were found in subcortical or peripheral nerve activity. Thus, criticality may represent a parsimonious organizing principle of variability in stimulus-related brain processes on a cortical level, possibly reflecting a delicate equilibrium between robustness and flexibility of neural responses to external stimuli.Significance StatementVariability of neural responses in primary sensory areas is puzzling, as it is detrimental to the exact mapping between stimulus features and neural activity. However, such variability can be beneficial for information processing in neural networks if it is of a specific nature, namely if dynamics are poised at a so-called critical state characterized by a scale-free spatio-temporal structure. Here, we demonstrate the existence of a link between signatures of criticality in ongoing and evoked activity through cortical excitability, which fills the long-standing gap between two major directions of research on neural variability: The impact of instantaneous brain states on stimulus processing on the one hand and the scale-free organization of spatio-temporal network dynamics of spontaneous activity on the other.

Effect of the Anesthetic Tricaine (MS-222) on Nerve Activity in the Anterior Lateral Line of the Oyster Toadfish, Opsanus tau

2004 ◽  
Vol 92 (2) ◽  
pp. 1034-1041 ◽  
Author(s):  
Lucy M. Palmer ◽  
Allen F. Mensinger
Keyword(s):  
Lateral Line ◽  
Neural Activity ◽  
Water Current ◽  
Lateral Line Nerve ◽  
Opsanus Tau ◽  
Spontaneous Neural Activity ◽  
Afferent Fibers ◽  
Primary Afferent Fibers ◽  
Oyster Toadfish ◽  
Evoked Activity

Inductive neural telemetry was used to record from microwire electrodes chronically implanted into the anterior lateral line nerve of the toadfish, Opsanus tau. Spontaneous neural activity and the response of lateral line fibers to water current were continually monitored from 17 primary afferent fibers before, during, and after the administration of the anesthetic tricaine (MS-222). Significant decrease in spontaneous and evoked activity and increase in interspike interval was noted when anesthetic concentrations were ≥0.010%. Neural activity returned to control levels within ∼90 min of anesthetic withdrawal. Decreasing the pH of the solution without the anesthetic caused transient heightened sensitivity, indicating that tricaine and not the concurrent drop in pH was responsible for the decrease in sensitivity during anesthesia. During a secondary challenge with the anesthetic 24 h after the first, fibers initially showed faster recovery however overall recovery kinetics were similar. Although high tricaine concentration was correlated with decreased neural sensitivity, the concentrations normally used to maintain anesthesia in the toadfish did not have significant effect on the evoked firing rate. Thus given sufficient time to recover from the induction of surgical anesthesia, it may be possible to maintain the animal under light anesthesia while minimizing the physiological effects of tricaine.

scholarly journals Cross-species neuroscience: closing the explanatory gap

2020 ◽  
Vol 376 (1815) ◽  
pp. 20190633
Author(s):  
Helen C. Barron ◽  
Rogier B. Mars ◽  
David Dupret ◽  
Jason P. Lerch ◽  
Cassandra Sampaio-Baptista
Keyword(s):  
Human Brain ◽  
Neural Activity ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Explanatory Gap ◽  
Temporal Precision ◽  
Common Space ◽  
Non Invasive ◽  
Spatio Temporal ◽  
The Explanatory Gap

Neuroscience has seen substantial development in non-invasive methods available for investigating the living human brain. However, these tools are limited to coarse macroscopic measures of neural activity that aggregate the diverse responses of thousands of cells. To access neural activity at the cellular and circuit level, researchers instead rely on invasive recordings in animals. Recent advances in invasive methods now permit large-scale recording and circuit-level manipulations with exquisite spatio-temporal precision. Yet, there has been limited progress in relating these microcircuit measures to complex cognition and behaviour observed in humans. Contemporary neuroscience thus faces an explanatory gap between macroscopic descriptions of the human brain and microscopic descriptions in animal models. To close the explanatory gap, we propose adopting a cross-species approach. Despite dramatic differences in the size of mammalian brains, this approach is broadly justified by preserved homology. Here, we outline a three-armed approach for effective cross-species investigation that highlights the need to translate different measures of neural activity into a common space. We discuss how a cross-species approach has the potential to transform basic neuroscience while also benefiting neuropsychiatric drug development where clinical translation has, to date, seen minimal success. This article is part of the theme issue ‘Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity’.

Wellness Dimensions Relate to Large-Scale Achievement and Behavioral Outcomes

2014 ◽  
Author(s):  
Eric Vreeman ◽  
Robert Brett Nelson ◽  
Donna Schnorr
Keyword(s):  
Large Scale ◽  
Behavioral Outcomes

scholarly journals GIANA allows computationally-efficient TCR clustering and multi-disease repertoire classification by isometric transformation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hongyi Zhang ◽  
Xiaowei Zhan ◽  
Bo Li
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Large Scale ◽  
Cell Receptor ◽  
Alignment Algorithm ◽  
Computationally Efficient ◽  
Antigen Specificity ◽  
Non Invasive ◽  
Isometric Transformation ◽  
Specific Receptors

AbstractSimilarity in T-cell receptor (TCR) sequences implies shared antigen specificity between receptors, and could be used to discover novel therapeutic targets. However, existing methods that cluster T-cell receptor sequences by similarity are computationally inefficient, making them impractical to use on the ever-expanding datasets of the immune repertoire. Here, we developed GIANA (Geometric Isometry-based TCR AligNment Algorithm) a computationally efficient tool for this task that provides the same level of clustering specificity as TCRdist at 600 times its speed, and without sacrificing accuracy. GIANA also allows the rapid query of large reference cohorts within minutes. Using GIANA to cluster large-scale TCR datasets provides candidate disease-specific receptors, and provides a new solution to repertoire classification. Querying unseen TCR-seq samples against an existing reference differentiates samples from patients across various cohorts associated with cancer, infectious and autoimmune disease. Our results demonstrate how GIANA could be used as the basis for a TCR-based non-invasive multi-disease diagnostic platform.

Large-scale visualization of dispersion of liquid-exfoliated two-dimensional nanosheets

2021 ◽  
Author(s):  
Xingyu Cui ◽  
Wen ying Shi ◽  
Chao Lu
Keyword(s):  
Aqueous Solution ◽  
Large Scale ◽  
Fluorescence Microscope ◽  
Visualization Method ◽  
Two Dimensional ◽  
Non Invasive

An ultrafast, non-invasive and large-scale visualization method has been developed to evaluate the dispersion of two-dimensional nanosheets in aqueous solution with fluorescence microscope by formation of excimers from improvement of...

scholarly journals Beyond Newgrange: Brú na Bóinne in the later Neolithic

2021 ◽  
pp. 1-30
Author(s):  
Stephen Davis ◽  
Knut Rassmann
Keyword(s):  
Large Scale ◽  
Morphological Characteristics ◽  
World Heritage ◽  
Geophysical Survey ◽  
World Heritage Site ◽  
Late Neolithic ◽  
Non Invasive ◽  
Heritage Site ◽  
New Evidence

The Brú na Bóinne World Heritage Site, Ireland is best known for its megalithic monuments, in particular the great developed passage tombs of Knowth, Dowth, and Newgrange, and its abundance of megalithic art. However, our understanding of the wider Brú na Bóinne landscape has changed beyond all recognition in the last decade owing to the application of modern, non-invasive survey technologies – in particular LiDAR and large-scale geophysical survey – and most recently as a result of the hot, dry summer of 2018 which revealed a series of remarkable cropmarks between Newgrange and the River Boyne. Despite a lack of excavation it can be argued, based on their morphological characteristics, that many of the structures revealed belong within the corpus of late Neolithic ritual/ceremonial structures, including earthen henges, square-in-circle monuments, palisaded enclosures, and pit/post-alignments. These display both extraordinary diversity, yet also commonality of design and architecture, both as a group and with the passage tombs that preceded them. This paper provides an up-to-date survey of the late Neolithic and presumed late Neolithic landscape of Brú na Bóinne. It provides new evidence and new insights from ongoing survey campaigns, suggesting parallels within the British Neolithic but also insular development within some monument classes.

Republication of “A Propensity Score Matching Analysis of the Effects of Special Education Services”

2017 ◽  
Vol 50 (4) ◽  
pp. 197-214 ◽  
Author(s):  
Paul L. Morgan ◽  
Michelle L. Frisco ◽  
George Farkas2 ◽  
Jacob Hibel
Keyword(s):  
Special Education ◽  
Propensity Score ◽  
Large Scale ◽  
Children With Disabilities ◽  
Behavioral Outcomes ◽  
Special Education Services ◽  
Education Services ◽  
Education Professionals ◽  
Propensity Score Matching Analysis ◽  
Services And Supports

Editor’s Note Since the landmark enactment of Education of the Handicapped Act in 1975, special education supports and services have been provided to children with disabilities. Although costly, the intentionality of these specialized services has been to advance the educational and societal opportunities of children with disabilities as they progress to adulthood. For our republished article in this issue of JSE’s 50th anniversary volume, we have selected an article by Paul Morgan, Michelle Frisco, George Farkas, and Jacob Hibel. In this research, Morgan and his colleagues quantified the effectiveness of special education services on children’s learning and behavioral outcomes using large-scale longitudinal data. Their results challenge all education professionals to explore ways to increase the effectiveness of special education and to document research efforts that provide clear evidence that the services and supports provided to individuals with disabilities are improving the extent to which they fully experience the benefits of education and participate fully in society.

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