Questions tagged [eeg]

The recording of voltages along the scalp for the purpose of monitoring brain wave activity and localizing sources of ionic currents

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1answer
30 views

Filtering artefacts and filtering short signals

I have a signal from EEG sensors and I try to denoise it from AC frequencies. For that reason, I estimated PSD of my signal and found that 50 Hz and 100 Hz are likely to represent noise. I constructed ...
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13 views

Permutation test on two simultaneously recorded EEG signals

I have two EEG signals that are simultaneously recorded (and has been further synced) using two EEG devices, namely device 1 (ground truth) and device 2 (investigational device). Imagine one device ...
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1answer
24 views

How to determine a suitable threshold when using amplitude thresholding method for spike detection?

I have seen number of approaches that have been introduced in the literature for spike detection including, amplitude thresholding method, Nonlinear Energy Operator method, and template matching ...
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2answers
41 views

Comparing similarity of two simultaneously recorded EEGs in freq domain

I have two EEG signals that are simultaneously recorded during the night (sleep). Imagine one device recorded from channel F4 and the other from Fp2. Now I would like to check the similarity of these ...
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19 views

How can a CNN account for spectro-temporal constraints in neural data?

What are there the best ways to leverage the unique "geometrical" constraints of spectro-temporal signal representations (architecture, filter shapes, data augmentation, etc.)? For example, ...
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5 views

Adding EOG noise to EEG signal

i have a data set from 2005 bci competition. it is removed from EOG components. to classification i want to apply deep learning methods on it. the problem is i want to survey deep learning performance ...
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1answer
29 views

Baseline correction for continuous EEG signals

I'm new to the topic so forgive the trivial question. I am trying to understand data preprocessing for EEG signals. As I understand, after recording continuous EEG signals, they should be band-pass ...
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32 views

VHF Artifact Contaminating Electrophysiological Sleep Signals

I am trying to remove an artifact from a VHF transmitter (programmed at a frequency of 148535; 1.5sec between 200ms pulses; 1.7sec peak to peak) from a sleep recording (polysomnography recording with ...
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27 views

Classifying motor imagery from EEG data: Feature selection

I am an undergraduate student who is trying to classify motor imagery from EEG data! I have no experience working with EEG or any neuroscience background, I only have a very basic knowledge of how ...
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40 views

Should A/D resolution affect EEG signal properties and how?

I encounter a curious situation wherein the recording device of my EEG data appears to affect how many transients of definition "x" I find, especially strange since the amplitude criterion is relative ...
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8 views

Performing CSP, decomposed eigenvalue of composite covariance matrix has zero, what went wrong?

So I tried to perform common spatial pattern (CSP) on BCI dataset IV 2A, there are four class, but I only grab 2 of them left and right motor imagery. I was following the step in this paper https://...
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31 views

EEG signal windowing and framing in python

I would like to do EEG signal(using 1 channel) Windowing and Framing. Actually I am doing my thesis and following a research paper.In this paper they explained "Windowing consists of dividing ...
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2answers
86 views

How to get Spectrogram after fft in matlab?

I have many EEG signals which record at 100 Hz. I use FFT on them with fft Matlab toolbox. Now I wanted to get a Spectrogram. As I searched and read a lot, I figure that I should window my signal and ...
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47 views

How to separate EEG frequency band in python?

Sorry for stupid question! I am very new in EEG signal processing and python environment.I have started my a project work related to EEG signal analysis using MNE. I would like to separate EEG Bands ...
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36 views

Removal of EEG noise using cascading adaptive filtering technique

I am required to filter out noise from EEG data using preferably Python or MATLAB. My dataset contains values for 64-electrode EEG along with their time-corresponding HEOG (horizontal eye movement), ...
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14 views

EEG signal dataset info

So I wanted to use pre processing on EEG data obtained from BCI competition 2005 dataset iiia which is a multiclass dataset. This data has lots of info on it but i cant seem to obtain/get data other ...
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2answers
620 views

Difference between bandpass filter and using fast fourier transform to extract power of frequency bands

In signal processing, I have heard of two terms: Using band-pass filter to extract some frequency bands. Using Discrete/Fast Fourier Transform (DFT/FFT) to extract some frequency bands. Are these ...
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2answers
44 views

Extracting different frequency bands (alpha, beta, gamma) from brain activity data

I am new to signal processing and despite googling about my question, I still couldn't find the solution. I have an Electrocorticography (ECoG) dataset. This consists of recording brain activity from ...
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45 views

frequency amplitude asymmetry

I want to calculate the frequency amplitude asymmetry between two signals, EEG signals in particular. As a result, I expect a value ranging from 0 to 1. I have some references regarding that, but it's ...
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20 views

Cross location Cross frequency coupling

Let's say there are 2 sensors recording data at some sampling rate. I'd like to know, how to calculate Cross frequency coupling (Phase amplitude coupling, for now) between these 2 channels ? I have ...
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33 views

Using unlabeled EEG data for Machine Learning

I am working on a project that is basically a game for motor-paralyzed people. It should take an EEG signal from FP1 channel of brain and then after processing it should generate command for the game ...
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51 views

How to normalize features after windowing for future test data?

I have an eeg data about 10 minutes. I want to extract some features (e.g. statistical features, power spectrum features, interchannel features, . . .) from this data to apply them to the machine ...
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54 views

How to compare imaginary coherence values?

High, I am currently writing my Master's thesis on susceptibility for hypnosis. I am comparing EGG signals of lowly and highly susceptible individuals. The imaginary coherence is given by: $$ \...
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36 views

Why my Time-Frequency plot is time reversed?

I'm trying to build my own code implementation for Continuous Wavelet Fourier Transform. But when I compare the time-frequency plot created with my function with time-frequency plot created with the ...
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1answer
150 views

What Is Meant by Clustering of ICA (Independent Component Analysis) Components?

I'm following the EEGLAB tutorial about STUDY creation and manipulation of the datasets, and came across the concept of clustering of ICA components. I'm not too familiar with processing of ICA ...
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1answer
1k views

Python tool for time-frequency analysis

I am trying to perform time-frequency analyses using the PyWavelets (pywt) toolkit for python. My ultimate goal is to perform time-frequency analyses for EEG signals but I am starting with something ...
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1answer
150 views

Can Kalman filter remove 50 Hz noise?

I'm dealing with a brain stimulation. My EEG contains large spikes (>3 mV) when stimulation occurs. I want to remove the 50 Hz noise, but I can't use notch filter because it creates large artifacts. ...
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169 views

How to find Coefficients of Autoregressive (AR) model using least means square (LMS) Algorithm without having future signal?

I want to do two things. Estimating Coefficients of AR model using LMS Using Coefficients found in step 1 and predict future samples of a signal using AR equation. I don't have a desired signal so I ...
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1answer
122 views

How to apply baseline methods to MNE preprocessed raw EEG signals?

I am new at EEG preprocessing and classification. I have followed Clemens Brunner's blog https://cbrnr.github.io/2018/01/29/removing-eog-ica/ as a tutorial for MNE. This is how I have preprocessed ...
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2answers
143 views

Augmentation for EEG signal classification using Deep Learning

Augmentation is a technique that we use in deep learning for expanding the training dataset. It includes different ways of modifying an image and adding it to the training dataset. My question is if ...
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52 views

How to account for number of electrodes in EEG data while converting to frequency domain?

I have raw data from 64 electrode EEG in CSV format where there are multiple rows and 64 columns. I am using the following Python code to separate the data into frequency bands: ...
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2answers
172 views

May I know how to find Time frequency power spectrogram of a signal?

I am analyzing EEG signal and I am unable to understand the term Time-Frequency Power Spectrogram. Please Can anyone help me? Thank you in advance.
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3answers
50 views

Can an EEG be re-sampled to fix a poor voltage resolution?

I’ve made quite a bad mistake in ca. 14 EEG recordings – I recorded at 10uV resolution @ 5000 Hz instead of 0.1 uV @ 500 Hz. I’m conducting an ERP experiment, and the signals of interest are on the ...
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1answer
188 views

Manual filter or digital filter first for EEG?

I am getting conflicting advise regarding how to clean my EEG data: 1) Manually remove artefacts first and then apply digital filters OR 2) Apply digital filters first and then manually remove ...
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1answer
285 views

Wavelet transform and FFT using to extract feature power bands with EEG signals

I am using 5 channels [ fz , cz , c3 , c4 , pz] to detect drowsiness of driver My First Question is, what is the right input to get feature power band ( Theta , alpha , gamma , beta ) to wavelet ...
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1answer
402 views

Common Spatial Pattern for EEG Signals

I am having difficulty in understanding the use of CSP for EEG signal feature extraction and subsequently. Since I am using two classes, this query will be restricted to it. In essence CSP requires 2 ...
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1answer
154 views

Spatial spectrum of EEG data: non-uniform DFT?

I want to compute the spatial spectrum of EEG data collected using a non-uniformly sampled grid of sensors (as in the figure below). One way to do this would be to interpolate the data on a ...
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0answers
366 views

output shape of STFT

I cant figure out why our output image is 257 * 32 , 32 I know why , but 257 I cant understand ? this is the exact word of this paper wich applied STFT on 3 channel of eeg signal : Short time Fourier ...
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1answer
1k views

How to apply Hamming Window and compute FFT?

I'm borrowing an EEG device whose accompanying software also computes the FFT of the data it collects. The software provides the user with a file of EEG values and a file of FFT values computed from ...
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1answer
86 views

EEG, PSI interpretation

My colleague and I started exploring EEG processing and, especially, functional connectivity. We decided to try the Phase Slope Index (PSI) and conducted a simple experiment as follows: it consists of ...
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2answers
120 views

How do I know if my EEG signal need denoising?

I recently started working on sleep study. For my research I download sleep EEG data from physionet. The EEG data has 100 Hz sampling rate and was recorded from 2 bipolar EEG site. When I start the ...
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3answers
8k views

How to correctly compute the EEG Frequency Bands with Python?

so I am trying to compute the EEG(25 channels, 512 sampling rate, 248832/channel) bands (alpha, beta, gamma, etc.) with Python. I managed to do so by: firstly filtering the signal with a butterworth ...
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1answer
3k views

How to compute the power bands of an eeg signal using python?

so I have an eeg signal (edf format) that has 25 channels and 248832 entries, sampling frequency of 512Hz. I have to compute the frequency bands: – Delta: 0.1-4Hz – Theta: 4-8Hz – Alpha: 8-12Hz – ...
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1answer
456 views

DWT versus band-pass filter

Which technique gives better result in extracting a band from a signal, let's say the alpha band (8-13 Hz): using a band-pass-filter or a DWT (Discrete Wavelet Transformation)? P.S.: I am working in ...
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1answer
44 views

What is the meaning of negative second for a Morlet wavelet?

I kind of familiar with wavelet transform (I just used it in code but do not have a deep understanding about it). I've been reading an article and came across this sentence: where 4Fs is the ...
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1answer
2k views

why butterworth bandpass filter changes signal in the passband?

I want to apply a butterworth bandpass filter to EEG signals and it's not working so I tried with a simple signal: t=[0:0.01:10]; s3= 9*sin(2*pi*4*t); Still ...
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2answers
419 views

Compute absolute power spectrum in MATLAB

I have EEG signals. Is there a way to compute the absolute power spectrum in MATLAB within a frequency band? I know I have to use the fft function but I can't find any details about the absolute power ...
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1answer
2k views

Compute phase coherence between two eeg signals

I have two EEG signals/channels and I would like to compute phase coherence in MATLAB. I have this paper: https://www.nature.com/npp/journal/v39/n5/full/npp2013330a.html but it does not say what Sij ...
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2answers
12k views

What does epoch mean in EEG?

I need to understand the meaning of an epoch in EEG signal. I have an EEG signal. Then how can I get the epoch?
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414 views

How to choose notch frequencies for filtering line noise?

I'm using the function to filter out line noise at 60 Hz (and 120, 180 Hz) caused by electrical noise: ecogNotch In the case below I can effectively filter out the line noise with a notch filter at ...