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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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 ...
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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 ...
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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 ...
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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).
...
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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 ...
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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 ...
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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 ...
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How to epoch EEG data with continuous stimuli for TRF analysis
I'm running a study with continuous stimuli, I send triggers at the beginning and end of a period of recording (the time duration for each period is not fixed). I'm planning to analyse the data with ...
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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 ...
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How to measure synchrony between EEG frequency bands illustrated in PSD values
I am investigating the synchrony measures among EEG frequency bands. However my dataset has only PSD values (in frequency domain). I found out that measures like Granger Causality are good but they ...
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How to analyze OpenBCI eye blink open dataset?
recently i am trying to anaylize eeg dataset(especially eye blinking).
Anyone can help to parse and understand this dataset?
Dataset file is Voluntary-Involuntary Eye-Blinks(https://drive.google.com/...
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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 ...
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Using readPLXFileC function in MATLAB for analysis on EEG
I am currently using a matlab function "readPLXfileC.c" to read plx data(of eeg) signal. Can anybody help me, how to do separate the channels, so that I can perform pre-processing on the ...
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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 ...
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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 ...
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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 ...
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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, ...
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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 (...
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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....
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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 ...
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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 ...
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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 (...
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How do I make a graph of pseudo frequency vs. time. in ssqueezepy?
How do I make the y axis in psuedo-frequency?
...
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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 ...
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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:)
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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 ...
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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 ...
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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:
...
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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 ...
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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 ?
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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 ...
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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 ...
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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 ...
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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?
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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 ...
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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. ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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121
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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 ...
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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 ...
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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?
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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, ...
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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....
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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 ...
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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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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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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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