|
|
# Description
|
|
|
The ICA plugin will apply differents algorithms to extract independent components from the signals.
|
|
|
The default and most used algorithm in EEG/MEG is infomax.
|
|
|
Two extras algorithm have been added, CCA and SOBI that seem to work better on EEG signals.
|
|
|
|
|
|
**This plugin can be run using the command line.**
|
|
|
|
|
|
# Running the process
|
|
|

|
|
|
|
|
|
## Select algorithm
|
|
|

|
|
|
|
|
|
Currently only two algorithms are available: infomax and sobi.
|
|
|
Note that depending on the selected algorithm the Extra parameters section of the GUI may vary.
|
|
|
|
|
|
## Filter the data (or not)
|
|
|
You may apply high pass/low pass filters on data.
|
|
|
If the values are set to zeros, a warning message will appear requesting a confirmation that you will process on raw data.
|
|
|
The Decimate Data is off by default. Check it on to speed up computation by removing some data points.
|
|
|
|
|
|
## Select the channels
|
|
|

|
|
|
You can process ICA on raw channels present on the current data file OR choose to compute only on channels present in the current Montage.
|
|
|
|
|
|
If you process SEEG data you can also restrict the computation to a particular SEEG Electrode.
|
|
|
|
|
|
## Avoid artefacts and/or compute only on some part of the data
|
|
|
If the current file contains markers, you will see a Data Input Options appears in the GUI:
|
|
|

|
|
|
|
|
|
You may use the options to avoid marked artefacted data and or restrict the computation on some marked parts of data.
|
|
|
|
|
|
## Ignore bad channels
|
|
|
That is the default behavior. If bad channels had been marked previously, they will be ignored during the computation.
|
|
|
|
|
|
## Number of components
|
|
|
By default the maximum of components will be extracted from the data.
|
|
|
You can however reduce the dimensions of the data (using a PCA) to get less components.
|
|
|
|
|
|
## Output
|
|
|
If you are currently working on data stored in a BIDS the output MATLAB file will be stored in the derivatives folder of your BIDS.
|
|
|
If you are not working with BIDS the output MATLAB file will be generated in the current data file folder.
|
|
|
The file name is BIDS alike providing useful information just by reading it.
|
|
|
|
|
|
# MATLAB file description
|
|
|
If you develop your own ICA algorithm in MATLAB, you can create a compatible file to load with AnyWave to see the components time series.
|
|
|
To do so you must create a file like the one AnyWave generates.
|
|
|
|
|
|
| variable name | type | description/values |
|
|
|
| ------ | ------ | ------ |
|
|
|
| modality | string | MEG, EEG, SEEG |
|
|
|
| hpf | double | high pass filter used or 0. |
|
|
|
| lpf | double | low pass filter used or 0. |
|
|
|
| sr | double | data sampling rate in Hz. |
|
|
|
| labels | cell array of strings | labels of electrodes |
|
|
|
| mixing | matrix (m x ic) | used to reject component(s) and rebuild the signals |
|
|
|
| unmixing | matrix (ic x m) | used to generate components time series |
|
|
|
|
|
|
m = number of channels.
|
|
|
ic = number of independent components.
|
|
|
|
|
|
IMPORTANT: labels must contains the electrodes used to compute. AnyWave will unmix those channels to get the ICA time series.
|
|
|
|
|
|
**NOTE:** the order of the labels must match the columns of matrix mixing.
|
|
|
The labels must exit in the data file (the names must match otherwise AnyWave will not be able to compute the time series by unmixing the original signals).
|
|
|
Each column of mixing is a component mapping for an electrode. The columns are used to compute components mappings.
|
|
|
|
|
|
|
|
|
# [Run ICA from the command line](plugin_ica_cli) |