Band‐limited power flow into enclosures

1977 ◽  
Vol 62 (4) ◽  
pp. 906-911 ◽  
Author(s):  
L. D. Pope ◽  
J. F. Wilby
Keyword(s):  
Power Flow ◽  
Limited Power ◽  
Band Limited

Band‐limited power flow into enclosures. II

1980 ◽  
Vol 67 (3) ◽  
pp. 823-826 ◽  
Author(s):  
L. D. Pope ◽  
J. F. Wilby
Keyword(s):  
Power Flow ◽  
Limited Power ◽  
Band Limited

scholarly journals A unifying principle underlying the extracellular field potential spectral responses in the human cortex

2015 ◽  
Vol 114 (1) ◽  
pp. 505-519 ◽  
Author(s):  
Ella Podvalny ◽  
Niv Noy ◽  
Michal Harel ◽  
Stephan Bickel ◽  
Gal Chechik ◽  
...  
Keyword(s):  
Field Potential ◽  
Neuronal Activation ◽  
Human Cortex ◽  
Neuronal Process ◽  
High Gamma ◽  
Neuronal Processes ◽  
Limited Power ◽  
Visuomotor Tasks ◽  
Band Limited ◽  
Spectrum Slope

Electrophysiological mass potentials show complex spectral changes upon neuronal activation. However, it is unknown to what extent these complex band-limited changes are interrelated or, alternatively, reflect separate neuronal processes. To address this question, intracranial electrocorticograms (ECoG) responses were recorded in patients engaged in visuomotor tasks. We found that in the 10- to 100-Hz frequency range there was a significant reduction in the exponent χ of the 1/ fχ component of the spectrum associated with neuronal activation. In a minority of electrodes showing particularly high activations the exponent reduction was associated with specific band-limited power modulations: emergence of a high gamma (80–100 Hz) and a decrease in the alpha (9–12 Hz) peaks. Importantly, the peaks' height was correlated with the 1/ fχ exponent on activation. Control simulation ruled out the possibility that the change in 1/ fχ exponent was a consequence of the analysis procedure. These results reveal a new global, cross-frequency (10–100 Hz) neuronal process reflected in a significant reduction of the power spectrum slope of the ECoG signal.

scholarly journals Different dynamic resting state fMRI patterns are linked to different frequencies of neural activity

2015 ◽  
Vol 114 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Garth John Thompson ◽  
Wen-Ju Pan ◽  
Shella Dawn Keilholz
Keyword(s):  
Neural Activity ◽  
Attention Deficit Disorder ◽  
Resting State ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Periodic Patterns ◽  
Limited Power ◽  
Band Limited ◽  
Additional Support ◽  
Network Mapping

Resting state functional magnetic resonance imaging (rsfMRI) results have indicated that network mapping can contribute to understanding behavior and disease, but it has been difficult to translate the maps created with rsfMRI to neuroelectrical states in the brain. Recently, dynamic analyses have revealed multiple patterns in the rsfMRI signal that are strongly associated with particular bands of neural activity. To further investigate these findings, simultaneously recorded invasive electrophysiology and rsfMRI from rats were used to examine two types of electrical activity (directly measured low-frequency/infraslow activity and band-limited power of higher frequencies) and two types of dynamic rsfMRI (quasi-periodic patterns or QPP, and sliding window correlation or SWC). The relationship between neural activity and dynamic rsfMRI was tested under three anesthetic states in rats: dexmedetomidine and high and low doses of isoflurane. Under dexmedetomidine, the lightest anesthetic, infraslow electrophysiology correlated with QPP but not SWC, whereas band-limited power in higher frequencies correlated with SWC but not QPP. Results were similar under isoflurane; however, the QPP was also correlated to band-limited power, possibly due to the burst-suppression state induced by the anesthetic agent. The results provide additional support for the hypothesis that the two types of dynamic rsfMRI are linked to different frequencies of neural activity, but isoflurane anesthesia may make this relationship more complicated. Understanding which neural frequency bands appear as particular dynamic patterns in rsfMRI may ultimately help isolate components of the rsfMRI signal that are of interest to disorders such as schizophrenia and attention deficit disorder.

scholarly journals Origins of 1/f-like tissue oxygenation fluctuations in the murine cortex

2020 ◽  
Author(s):  
Qingguang Zhang ◽  
Kyle W. Gheres ◽  
Patrick J. Drew
Keyword(s):  
Neural Activity ◽  
Power Distribution ◽  
Tissue Oxygenation ◽  
Field Potential ◽  
Two Photon ◽  
Stochastic Fluctuations ◽  
Discrete Nature ◽  
Limited Power ◽  
Band Limited ◽  
The Brain

AbstractThe concentration of oxygen in the brain spontaneously fluctuates, and the power distribution in these fluctuations has 1/f-like dynamics. Though these oscillations have been interpreted as being driven by neural activity, the origins of these 1/f-like oscillations is not well understood. Here, to gain insight of the origin of the 1/f-like oxygen fluctuations, we investigated the dynamics of tissue oxygenation and neural activity in awake behaving mice. We found that oxygen signal recorded from the cortex of mice had 1/f-like spectra. However, band-limited power in the local field potential, did not show corresponding 1/f-like fluctuations. When local neural activity was suppressed, the 1/f-like fluctuations in oxygen concentration persisted. Two-photon measurements of erythrocyte spacing fluctuations (‘stalls’) and mathematical modelling show that stochastic fluctuations in erythrocyte flow and stalling could underlie 1/f-like dynamics in oxygenation. These results show discrete nature of erythrocytes and their irregular flow, rather than neural activity, could drive 1/f-like fluctuations in tissue oxygenation.

scholarly journals Origins of 1/f-like tissue oxygenation fluctuations in the murine cortex

PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001298
Author(s):  
Qingguang Zhang ◽  
Kyle W. Gheres ◽  
Patrick J. Drew
Keyword(s):  
Neural Activity ◽  
Tissue Oxygenation ◽  
Field Potential ◽  
Low Frequencies ◽  
Two Photon ◽  
Stochastic Fluctuations ◽  
Discrete Nature ◽  
Limited Power ◽  
Band Limited ◽  
Distribution Of Power

The concentration of oxygen in the brain spontaneously fluctuates, and the distribution of power in these fluctuations has a 1/f-like spectra, where the power present at low frequencies of the power spectrum is orders of magnitude higher than at higher frequencies. Though these oscillations have been interpreted as being driven by neural activity, the origin of these 1/f-like oscillations is not well understood. Here, to gain insight of the origin of the 1/f-like oxygen fluctuations, we investigated the dynamics of tissue oxygenation and neural activity in awake behaving mice. We found that oxygen signal recorded from the cortex of mice had 1/f-like spectra. However, band-limited power in the local field potential did not show corresponding 1/f-like fluctuations. When local neural activity was suppressed, the 1/f-like fluctuations in oxygen concentration persisted. Two-photon measurements of erythrocyte spacing fluctuations and mathematical modeling show that stochastic fluctuations in erythrocyte flow could underlie 1/f-like dynamics in oxygenation. These results suggest that the discrete nature of erythrocytes and their irregular flow, rather than fluctuations in neural activity, could drive 1/f-like fluctuations in tissue oxygenation.

Sign in / Sign up

Export Citation Format

Share Document