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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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1 answer
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What factors could affect the scale of PSD estimation?

I was required to program a function in R to estimate power spectral density of EEG data. The function I created is, I think, rather standard, and estimates the PSD of a signal by computing $$ \frac{2|...
lafinur's user avatar
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1 vote
1 answer
67 views

How to feed multi-channel spectrograms to Deep Neural Network?

I am using a 14 channel EEG device. To do away with the need for any handcrafted features, I wish to implement an ML classification task with the EEG data collected using deep neural networks (such as ...
Anantha Krishnan's user avatar
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0 answers
4 views

Is each label for any person for 288 trials in training session the same as 288 trials in evaluation session for BCIC-IV 2a dataset?

I have saved the label files and eeg data for each trial in .npy format. Now will it be the case that any trial, let's say, 12th trial of person 1 in training session label and 12th trial for person 1 ...
thinking_sapiens's user avatar
0 votes
0 answers
44 views

Is it possible to use np.fft.fft to pick out the Fourier coefficients from one timepoint, at a specific frequency?

I am trying to apply np.fft.fft on a 2D array of data of shape (98, 1024), where 98 is the number of trials and 1024 is the sampling rate in Hz. I am trying to find ...
Lisa Duan's user avatar
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0 answers
40 views

Use periods instead of frequencies in Comodulograms

I want to create a Comodulogram to assess PAC. I use the pactools library, which uses frequencies. Since I work with hourly data and want to look at multidien phases, it would be better to use periods ...
Rolandos's user avatar
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0 answers
33 views

EEG important values visualization

i have an array contains the EEG signal values called inputSignal, and another array contains the importance degree or the attribution value of the corresponding element in inputSignal array , i want ...
Soumia DJELLIKH's user avatar
0 votes
0 answers
25 views

Incorrect epoch labelling

I am processing an EEG signal acquired by showing 10 image of each of 40 classes. I want to label the signals converted to epochs to their corresponding class labels. The ...
madiha Rehman's user avatar
2 votes
0 answers
35 views

Event-related EEG (epoch averaging) as a form of inter-harmonic bandstop filtering?

There is a matter that comes to my mind from time to time, now I describe it in detail. Anyway I am a first year PhD student, doing research in the field of cognitive neuroscience, but yet I only have ...
LimeAndConconut's user avatar
0 votes
1 answer
100 views

What's actually inside these EEG values?

I have opened the file in Matlab and am using MNE Python too. This is a processed EEG file in Matlab data format instead of raw EEG (Screenshot 1). ...
tahsin's user avatar
  • 3
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0 answers
55 views

What are common pre-processing steps of EEG signals

I am new to EEG analysis, and I wonder what are the common pre-processing steps of EEG signals, for example, for motor imagery classification? Currently, my pre-processing steps include Epoch the ...
Chris Tang's user avatar
0 votes
1 answer
196 views

How EEG signal is windowed? Windowing vs Epoching are they same?

I am experimenting with EEG dataset from this (title: "The Perils and Pitfalls of Block Design for EEG Classification Experiments") paper. They have applied various ML models on different ...
madiha Rehman's user avatar
0 votes
1 answer
47 views

Normalize the output signal that may be as similar as possible the input

I'm having a problem to normalize my output signal (extracted EEG signal) after applying Independent Component Analysis (ICA) that may be as similar as the original source (EEG signal). I need do this ...
Văn Sư Hồ's user avatar
0 votes
0 answers
32 views

EEG filtration via EMG

i got little problem. I'm trying to detect HFOs in single channel EEG (the recording is multichannel, but there is not enough channels to use ICA) for my diploma thesis experiment and i want to first ...
Tousak's user avatar
  • 1
0 votes
1 answer
130 views

Bandpass filtering EEG and getting weird distortions, parameter issue?

I am trying to bandpass filter an EEG signal, nothing fancy but it's coming out pretty distorted. EEG data is taken from forehead. Sampling rate is 250 Hz. Cutoff is 2.5 Hz & 120 Hz. Tried in both ...
fillifilterbutterfly's user avatar
0 votes
1 answer
222 views

Understanding negative power in a time frequency heat plot

I am into analyzing EEG signals with the help of this guide. So, I choose to inspect power in a frequency region before and after an event of interest (at t=o) and ...
AvadaMouse's user avatar
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0 answers
170 views

how to load multiple samples in mne from a txt/csv file?

I have an EEG csv data set of 268 samples. In every sample, there's data for 6 EEG channels, and every channel has 896 data points (256 Hz, 3.5 s). At first, I interpolated and filtered the data one ...
Towsif Ahamed Labib's user avatar
0 votes
1 answer
475 views

How to calculate FIR filter coefficients?

I have EEG signal data (19 channels) sampled at 128Hz. I am trying to retrieve the coefficients that are mentioned in a research paper included below. To decompose an EEG signal, a digital FIR filter ...
M.V.Ramprakash's user avatar
2 votes
1 answer
2k views

filtering EEG data with scipy.signal

I have EEG data recorded with a sampling rate of 256 Hz. Each recording contains 19 EEG channels. Other channels (like ECG data) are ignored. The recordings of 10 patients are 20 minutes long each, ...
Hubert Schölnast's user avatar
0 votes
0 answers
84 views

Value of getting frequency bands of FFT for EEG signals

I'm trying to analyze and extract some frequency domain features for a simple machine learning model from EEG signals. I partitioned my data to 30s epochs and used np.fft to get the frequency and the (...
Warren Manuel's user avatar
0 votes
0 answers
650 views

How to calculate Diffential Entropy (DE) in Python?

I am working with a data which is actually the popular EEG data called DEAP. It basically is a 3D array of size (40, 40, 8064) and here is the link to the official dataset website: https://www.eecs....
Saturn_4's user avatar
4 votes
1 answer
824 views

How does SciPy's Welch function change the shape of the data?

I am working with some time series data with a shape of 8064. The data is actually the popular EEG data called DEAP. It basically is a 3D array of size (40, 40, 8064) and here is the link to the ...
Saturn_4's user avatar
0 votes
0 answers
9 views

Converting 2 variables (obtained by ICA decomposition) named A_ffdiag and W_ffdiag into mixing/unmixing matrix

I have two variables as a result of an ICA (Independent Component analysis) decomposition (decomposed using joint diagonalization algorithm which uses frobenius norm formulation) named A_ffdiag and ...
Anand's user avatar
  • 1
0 votes
1 answer
136 views

Should I be using FFT

I am using python (scipy.fft) to live analize EEG data. The app resonds instantl based on the signls coming from EEG (Alpha Beta...)The problem is that when I run the FFT on only 100 samples or so (...
Combobulated's user avatar
1 vote
0 answers
47 views

How do I make a graph of pseudo frequency vs. time. in ssqueezepy?

How do I make the y axis in psuedo-frequency? ...
Cameron Glick's user avatar
0 votes
0 answers
263 views

How to get epochs from eeg data in python?

I am working on sleep stage classification and have EEG data from the link : https://physionet.org/content/hmc-sleep-staging/1.1/ I am using pyedflib to extract the data. I am tring to extract the ...
FredyJames21's user avatar
0 votes
0 answers
38 views

Why when ploting the ICLabel in EEGLAB some of the IC topographs look exaclty the same?

I am attaching an image with the output of ICLabel. So you can see that IC5 and IC6 are the same. What does this mean? Thank you in advance:)
Eva's user avatar
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0 votes
0 answers
74 views

Issues on EEG PSD feature extraction using signal.welch

I am new to EEG signal processing and I am having some issues on calculating PSD using scipy.signal.welch. I am trying to implement a function to extract PSD features. The input of this function is a ...
Vicky Fi's user avatar
-1 votes
1 answer
383 views

How to calculate the average power of each frequency band?

I have EEG data from 30 participants, each recording is about 3 mins, and I'm trying to calculate the average power of each frequency band. I tried using Welch's or multitaper functions, but my values ...
laurahagedorn's user avatar
0 votes
1 answer
142 views

Doing the inverse of the fourier on EEG data?

I have EEG data. I have 51 values(complex numbers) that are supposed to represent the frequency. I plot the absolute values. They have negative values and have an imaginary component as well: ...
Borut Flis's user avatar
1 vote
1 answer
938 views

Should i normalize FFT signal with z-score?

I am working with EEG data (time domain) in a machine learning task, where each input signal must be mapped to a class/frequency. I am using FFT in order to get data in frequency domain and make ...
heresthebuzz's user avatar
0 votes
1 answer
75 views

How does ICA works with more than two sources

In all tutorials on ICA that i've seen, two sources are separated from each other. but how is two source separation different from multi-source separations like data recorded by EEG hats ?
Pooya Estakhri's user avatar
0 votes
1 answer
41 views

Regularity in EEG data

I've just started looking into EEG data using a Muse s and mind monitor. I've noted this very regular 4 Hertz (approximately) pattern and wonder if this is real or an artifact. Is it just a very ...
ericf's user avatar
  • 101
1 vote
1 answer
169 views

EEG peaks do not get identified at the correct frequencies

For my thesis I am re-analyzing a dataset where subjects were visually stimulated with 5.45, 8.57, 12 or 15 Hz. This well-known technique (steady state visual evoked potential) should elicit EEG peaks ...
Pelskens's user avatar
-1 votes
1 answer
677 views

Extracting EEG Bands from raw EEG signal to match with the Bands calculated on the sensor level

I have recently got my hands on a commercially available single channel EEG Sensor from Neurosky. This sensor acquire raw EEG signal at 512Hz from the frontal part of the human head and also process ...
Greyfrog's user avatar
  • 101
0 votes
0 answers
81 views

EEG Data Analysis

I have recorded EEG data using openBCI which is in the range of -15000 to 15000 micro volts. I want to reduce this to the range of -100 to 100 micro volts. How do I do it?
seenu_kulkarni's user avatar
0 votes
0 answers
83 views

Breaking EEG signal into epochs: why should we multipy windows-time length by frequency?

I am new to EEG data, Could you please explain why we need to multiply Fs by window_time_length ? I thought by defining window_time_length, we define the length of epoch! I am working on P300 BCI ...
user57724's user avatar
2 votes
1 answer
802 views

MATLAB's designfilt vs butter function

I am relatively new to signal processing, and have always used MATLAB's designfilt option for my signal processing needs. Recently, however, I have seen people just using MATLAB's butter function. ...
Kile Maze's user avatar
0 votes
3 answers
495 views

mne raw plot looks like vertical lines instead of the usual signal

I have a data from a single eeg channel. When I plot it with plt, it looks like a regular signal. However, when I'm trying to plot with mne raw object's method plot, it looks very strange, like ...
user12450767's user avatar
3 votes
0 answers
384 views

Edge artifacts in frequency-domain Moving Average filter

I am currently trying to implement in python an algorithm to identify and filter out one specific periodic EEG artifact -- the grad fMRI artifact -- as described in this paper, and I am incurring in ...
user213575's user avatar
0 votes
0 answers
33 views

Logic analyzer for acquiring EEG signals?

Is it possible? I haven't found anything about it on the internet. I found a logic analyzer here, which is marketed as having the capability to monitor analog signals too: "One useful feature of ...
LimeAndConconut's user avatar
0 votes
2 answers
127 views

Processes/Transforms involved to get brainwave data from raw EEG? (Autocorrelation confusion)

Not clear on what the autocorrelation function of raw EEG means physically why can't you take the FT of a the EEG itself and get frequency data? With BCI & basic electrode setups you can ...
ThermoRestart's user avatar
0 votes
0 answers
46 views

Does my filter desing for unusual EEG experiment looks good?

I have made some progress since my last question, and again I am asking you for advice. Hi, I'm still designing an unusual (in terms of signal analysis) EEG experiment, which forces me to design my ...
Bartek Kroczek's user avatar
0 votes
1 answer
130 views

Filter design for an unusual EEG experiment

I'm designing a quite unusual (in terms of signal analysis) EEG experiment, which forces me to design my own filter. I have never done this before, so kindly please check my work and suggest ...
Bartek Kroczek's user avatar
0 votes
2 answers
176 views

why is the signal divided into epochs in EEG classification?

I'm new in EEG signal classification. Studying the literature on this topic, I wonder why the EEG signals are divided in epochs, so, instead of classifying the whole signal all at once, we usually ...
volperossa's user avatar
0 votes
0 answers
110 views

DWT and FFT on a very low frequency signals

I am trying to extract features from a very low frequency signal of $0.1$ HZ and less than $100$ samples. Is it advisable to use FFT and DWT on this signal?
aven's user avatar
  • 1
0 votes
0 answers
239 views

EEGLab import .mat file

I am new to EEG and signal processing, anyone can please check if I fill in the right numbers? I am confused about those terms. For example, the recording using 22 EEG channels and 3 EOG channels, ...
Yo Yo's user avatar
  • 1
-1 votes
1 answer
293 views

Wrong values calculating FFT with EEG Bands using Numpy

First of all I have to say I am very new to these matters. I am trying to apply FFT algorithm to some values obtained by EEG bands. I found the following code but I am unable to make it work correctly....
NeoChiri's user avatar
2 votes
1 answer
276 views

EEG signal processing with wavelet or fft?

I have confusion about signal processing related with EEG signal. I have done some of my research and that made me more confused about processing and filtering the signal. Let me jump into the problem ...
B L Λ C K's user avatar
1 vote
1 answer
336 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 ...
Ilya Zisman's user avatar
0 votes
1 answer
557 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 ...
Tyesh's user avatar
  • 165