scholarly journals Neural rhythmic symphony of human walking observation: Upside-down and Uncoordinated condition on cortical theta, alpha, beta and gamma oscillations

2014 ◽  
Vol 8 ◽  
Author(s):  
David Zarka ◽  
Carlos Cevallos ◽  
Mathieu Petieau ◽  
Thomas Hoellinger ◽  
Bernard Dan ◽  
...  
Keyword(s):  
Gamma Oscillations ◽  
Human Walking ◽  
Alpha Beta

scholarly journals Neural activity during sentence processing as reflected in theta, alpha, beta, and gamma oscillations

NeuroImage ◽  
2016 ◽  
Vol 142 ◽  
pp. 43-54 ◽  
Author(s):  
Nietzsche H.L. Lam ◽  
Jan-Mathijs Schoffelen ◽  
Julia Uddén ◽  
Annika Hultén ◽  
Peter Hagoort
Keyword(s):  
Sentence Processing ◽  
Neural Activity ◽  
Gamma Oscillations ◽  
Alpha Beta

scholarly journals Preservation and Changes in Oscillatory Dynamics across the Cortical Hierarchy

2020 ◽  
Vol 32 (10) ◽  
pp. 2024-2035 ◽  
Author(s):  
Mikael Lundqvist ◽  
André M. Bastos ◽  
Earl K. Miller
Keyword(s):  
Local Field ◽  
Local Field Potentials ◽  
Gamma Oscillations ◽  
Field Potentials ◽  
Oscillatory Dynamics ◽  
Cortical Areas ◽  
Cortical Hierarchy ◽  
Alpha Beta ◽  
Spiking Activity ◽  
Prefrontal Cortices

Theta (2–8 Hz), alpha (8–12 Hz), beta (12–35 Hz), and gamma (>35 Hz) rhythms are ubiquitous in the cortex. However, there is little understanding of whether they have similar properties and functions in different cortical areas because they have rarely been compared across them. We record neuronal spikes and local field potentials simultaneously at several levels of the cortical hierarchy in monkeys. Theta, alpha, beta, and gamma oscillations had similar relationships to spiking activity in visual, parietal, and prefrontal cortices. However, the frequencies in all bands increased up the cortical hierarchy. These results suggest that these rhythms have similar inhibitory and excitatory functions across the cortex. We discuss how the increase in frequencies up the cortical hierarchy may help sculpt cortical flow and processing.

scholarly journals Multi-Channel Whole-Head OPM-MEG: Helmet Design and a Comparison with a Conventional System

2020 ◽  
Author(s):  
Ryan M. Hill ◽  
Elena Boto ◽  
Molly Rea ◽  
Niall Holmes ◽  
James Leggett ◽  
...  
Keyword(s):  
Functional Neuroimaging ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Quality Data ◽  
List Type ◽  
Viable Systems ◽  
Fundamental Limitations ◽  
Comparable Performance ◽  
Alpha Beta ◽  
Neuronal Current

ABSTRACTMagnetoencephalography (MEG) is a powerful technique for functional neuroimaging, offering a non-invasive window on brain electrophysiology. MEG systems have traditionally been based on cryogenic sensors which detect the small extracranial magnetic fields generated by synchronised current in neuronal assemblies, however such systems have fundamental limitations. In recent years quantum-enabled devices, called optically-pumped magnetometers (OPMs), have promised to lift those restrictions, offering an adaptable, motion-robust MEG device, with improved data quality, at reduced cost. However, OPM-MEG remains a nascent technology, and whilst viable systems exist, most employ small numbers of sensors sited above targeted brain regions. Here, building on previous work, we construct a wearable OPM-MEG system with ‘whole-head’ coverage based upon commercially available OPMs, and test its capabilities to measure alpha, beta and gamma oscillations. We design two methods for OPM mounting; a flexible (EEG-like) cap and rigid (additively-manufactured) helmet. Whilst both designs allow for high quality data to be collected, we argue that the rigid helmet offers a more robust option with significant advantages for reconstruction of field data into 3D images of changes in neuronal current. Using repeat measurements in two participants, we show signal detection for our device to be highly robust. Moreover, via application of source-space modelling, we show that, despite having 5 times fewer sensors, our system exhibits comparable performance to an established cryogenic MEG device. While significant challenges still remain, these developments provide further evidence that OPM-MEG is likely to facilitate a step change for functional neuroimaging.HIGHLIGHTSA 49-channel whole-head OPM-MEG system is constructedSystem evaluated via repeat measurements of alpha, beta and gamma oscillationsTwo OPM-helmet designs are contrasted, a flexible (EEG-like) cap and a rigid helmetThe rigid helmet offers significant advantages for a viable OPM-MEG device49-channel OPM-MEG offers performance comparable to established cryogenic devices

scholarly journals Preservation and changes in oscillatory dynamics across the cortical hierarchy

2020 ◽  
Author(s):  
Mikael Lundqvist ◽  
André M. Bastos ◽  
Earl K. Miller
Keyword(s):  
Prefrontal Cortex ◽  
Local Field ◽  
Gamma Oscillations ◽  
Field Potentials ◽  
Phase Coupling ◽  
Oscillatory Dynamics ◽  
Cortical Areas ◽  
Gamma Frequency ◽  
Cortical Hierarchy ◽  
Alpha Beta

AbstractTheta (2-8 Hz), Alpha (8-12 Hz), beta (12-35 Hz) and gamma (>35 Hz) rhythms are ubiquitous in cortex. But there is little understanding of whether they have similar properties and functions in different cortical areas because they have rarely been compared across them. We record neuronal spikes and local field potentials simultaneously at several levels of the cortical hierarchy in monkeys. Theta, alpha, beta and gamma oscillations had similar relationships to spiking activity in visual, parietal and prefrontal cortex. However, the frequencies in all bands increased up the cortical hierarchy. These results suggest that these rhythms have similar functions inhibitory and excitatory across cortex. We discuss how the increase in frequencies up the cortical hierachy may help sculpt cortical flow and processing.Significance statementPhase-coupling in alpha/beta and gamma frequency ranges between cortical areas is often viewed as a means to shape brain-wide communication. However, systematic frequency differences between communicating areas are typically not considered, but equally important. Here we show that alpha/beta and gamma oscillations are of systematically higher frequency ascending the cortical hierarchy. This presents a fresh view on a widely studied topic. It has important implications in shaping cortical communication and helps explain widely observed phenomena.

Foveal evoked magneto-encephalography features related to the parvocellular pathway

2008 ◽  
Vol 25 (2) ◽  
pp. 179-185 ◽  
Author(s):  
CHIA-YEN YANG ◽  
JEN-CHUEN HSIEH ◽  
YIN CHANG
Keyword(s):  
Signal Processing ◽  
Visual Stimulus ◽  
Visual Information ◽  
Healthy Subjects ◽  
Gamma Oscillations ◽  
Parvocellular Pathway ◽  
Non Invasive ◽  
Spatial Frequencies ◽  
Brain Responses ◽  
Alpha Beta

AbstractThe aim of this study was to use non-invasive magneto-encephalographic techniques, together with visual stimulus paradigms that can psychophysically separate the M- and P-pathways, to examine the physiological relations of the pathways at the fovea with (1) the magneto-encephalography components M70 and M100 (in latency and amplitude), and (2) the cortical oscillatory activities (alpha, beta, and gamma), respectively. The checkerboard stimuli accompanied with different spatial frequencies (SFs) (0.5 or 4 cycles per degree) were presented (within 2° of the retinal center) to six healthy subjects by using steady-pedestal and pulse paradigms, which could activate distinct populations of M- and P-neurons. SF analyzed brain responses in each paradigm. The results show a consistent trend in M70 and M100 with increased latencies and amplitudes in response to the high SF. Mean while, the beta to gamma activities are apparently enhanced by the stimulus of high SF, especially under pulse paradigm (p = 0.03). In this study, we suggest that M70 can be a good clue to characterize the P-pathway. Moreover, in the frequency analysis, the beta oscillations may serve for more detailed visual information, while the gamma oscillations seem to reflect the signal processing in the P-pathway and with sensitivity to the fovea.

scholarly journals Disentangling neocortical alpha/beta and hippocampal theta/gamma oscillations in human episodic memory formation

NeuroImage ◽  
2021 ◽  
pp. 118454
Author(s):  
Benjamin J. Griffiths ◽  
María Carmen Martín-Buro ◽  
Bernhard P. Staresina ◽  
Simon Hanslmayr
Keyword(s):  
Episodic Memory ◽  
Gamma Oscillations ◽  
Memory Formation ◽  
Alpha Beta ◽  
Hippocampal Theta

scholarly journals Attentional Modulation of Alpha/Beta and Gamma Oscillations Reflect Functionally Distinct Processes

2014 ◽  
Vol 34 (48) ◽  
pp. 16117-16125 ◽  
Author(s):  
M. Bauer ◽  
M.-P. Stenner ◽  
K. J. Friston ◽  
R. J. Dolan
Keyword(s):  
Gamma Oscillations ◽  
Attentional Modulation ◽  
Alpha Beta

Theta and Gamma Power Increases and Alpha/Beta Power Decreases with Memory Load in an Attractor Network Model

2011 ◽  
Vol 23 (10) ◽  
pp. 3008-3020 ◽  
Author(s):  
Mikael Lundqvist ◽  
Pawel Herman ◽  
Anders Lansner
Keyword(s):  
Working Memory ◽  
Single Cell ◽  
Network Model ◽  
Memory Load ◽  
Cell Activity ◽  
Gamma Oscillations ◽  
Attractor Network ◽  
Beta Power ◽  
Gamma Power ◽  
Alpha Beta

Changes in oscillatory brain activity are strongly correlated with performance in cognitive tasks and modulations in specific frequency bands are associated with working memory tasks. Mesoscale network models allow the study of oscillations as an emergent feature of neuronal activity. Here we extend a previously developed attractor network model, shown to faithfully reproduce single-cell activity during retention and memory recall, with synaptic augmentation. This enables the network to function as a multi-item working memory by cyclic reactivation of up to six items. The reactivation happens at theta frequency, consistently with recent experimental findings, with increasing theta power for each additional item loaded in the network's memory. Furthermore, each memory reactivation is associated with gamma oscillations. Thus, single-cell spike trains as well as gamma oscillations in local groups are nested in the theta cycle. The network also exhibits an idling rhythm in the alpha/beta band associated with a noncoding global attractor. Put together, the resulting effect is increasing theta and gamma power and decreasing alpha/beta power with growing working memory load, rendering the network mechanisms involved a plausible explanation for this often reported behavior.

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