Time-frequency analysis for the study of phase synchrony in the brain

2008 ◽  
Author(s):  
Selin Aviyente ◽  
Westley Evans
Keyword(s):  
Frequency Analysis ◽  
Phase Synchrony ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
The Brain

scholarly journals A better way to define and describe Morlet wavelets for time-frequency analysis

2018 ◽  
Author(s):  
Michael X Cohen
Keyword(s):  
Frequency Analysis ◽  
Time Series Data ◽  
Sine Wave ◽  
Stationary Time Series ◽  
Series Data ◽  
Time Frequency Analysis ◽  
Temporal Precision ◽  
Time Frequency ◽  
Number Of Cycles ◽  
The Brain

AbstractMorlet wavelets are frequently used for time-frequency analysis of non-stationary time series data, such as neuroelectrical signals recorded from the brain. The crucial parameter of Morlet wavelets is the width of the Gaussian that tapers the sine wave. This width parameter controls the trade-off between temporal precision and frequency precision. It is typically defined as the “number of cycles,” but this parameter is opaque, and often leads to uncertainty and suboptimal analysis choices, as well as being difficult to interpret and evaluate. The purpose of this paper is to present alternative formulations of Morlet wavelets in time and in frequency that allow parameterizing the wavelets directly in terms of the desired temporal and spectral smoothing (as full-width at half-maximum). This formulation provides clarity on an important data analysis parameter, and should facilitate proper analyses, reporting, and interpretation of results. MATLAB code is provided.

Localizing functional activity in the brain through time-frequency analysis and synthesis of the EEG

1996 ◽  
Vol 84 (9) ◽  
pp. 1302-1311 ◽  
Author(s):  
Mingui Sun ◽  
Shie Qian ◽  
Xiaopu Yan ◽  
S.B. Baumann ◽  
Xiang-Gen Xia ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Functional Activity ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Analysis And Synthesis ◽  
The Brain

scholarly journals Neural Oscillation Associated with Contagious Itch in Patients with Atopic Dermatitis

2021 ◽  
Vol 11 (4) ◽  
pp. 438
Author(s):  
In-Seon Lee ◽  
Kyuseok Kim ◽  
Hi-Joon Park ◽  
Hyangsook Lee ◽  
Won-Mo Jung ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Frequency Analysis ◽  
Mu Rhythm ◽  
Major Health ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
The Brain ◽  
Neurophysiological Basis ◽  
Insight Into ◽  
Increased Susceptibility

Objective: Itch is an unpleasant sensation associated with an urge to scratch and is a major health care issue associated with atopic dermatitis (AD). Contagious itch, i.e., subjective feelings of itchiness induced by watching others’ scratching behavior, is common in patients with AD. Using electroencephalography, we examined alpha (8–13 Hz) oscillations in sensorimotor areas associated with the desire to scratch in patients with AD. Methods: Thirty-six patients with AD and 34 healthy controls (HCs) participated in this study. They evaluated their itch levels after watching short videos of a model scratching or tapping parts of his body. Neural oscillations were recorded from nine electrodes, including those placed over sensorimotor areas. Time–frequency analysis was used to compare mu rhythm suppression over the sensorimotor areas in response to these videos between patients with AD and HCs. Results: The behavioral test showed that the visual stimuli induced increased feelings of itchiness in patients with AD relative to HCs under the tapping and scratching conditions. The time–frequency analysis revealed that mu rhythm suppression in response to scratching images was significantly prominent in patients with AD, but not in HCs. Conclusion: Patients with AD exhibited increased susceptibility to contagious itch. This phenomenon might be related to enhanced mu rhythm suppression in sensorimotor areas of the brain in these patients. Our findings provide new insight into the neurophysiological basis of itch sensations in patients with AD.

Time-Frequency Analysis of Partial Discharge Phenomena in SF6 gas using Wavelet Transform

1997 ◽  
Vol 117 (3) ◽  
pp. 338-345 ◽  
Author(s):  
Masatake Kawada ◽  
Masakazu Wada ◽  
Zen-Ichiro Kawasaki ◽  
Kenji Matsu-ura ◽  
Makoto Kawasaki
Keyword(s):  
Wavelet Transform ◽  
Frequency Analysis ◽  
Partial Discharge ◽  
Time Frequency Analysis ◽  
Time Frequency
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