EEG Pipeline
Import Data
The data will need to be opened in BESA on one of the analysis computers.
Set Channel Locations
Select the files that specifies the channel locations.
Delete or Interpolate Bad Channels
You may want to delete channels that are too noisy, such as the ones around the face.
Collect Data
The recorded data will be saved as a .mff file. This will need to be moved to the appropriate folder in Box.
Re-reference Data
You need to convert the data to an average reference.
Filtering
We use filters to take out signals that are definitley not brain data. You need to filter out the very low (<0.01-0.1 Hz) and very high frequencies (>50-100 Hz), as well as the 60 Hz line noise from the ambient electrical wires.
Run ICA
ICA is used to separate out the data into its various signal sources, which are both neural and non-neural.
Epoching
For each stimulus, we want to extract a segment of data just before and just after the stimulus.
Baseline Removal
The signal recorded just before the stimulus is considered the baseline. This is comprised of neural activity that is not in response to the stimulus as well as noise. This baseline is subtracted from the entire epoch, leaving the neural activity that occured in response to the stimulus.
Component Rejection
Once you've run ICA on a dataset, it is possible to reject non-neural signal sources. This section explains how to do that and explains the Sasica plug in.
Sorting by Stimulus Type
Separating the data for each stimulus type into its own file.
Analyze the Data
using one or more of these methods. The question you are asking will guide your analysis method selection.
Averaging Trials
Separating the data for each stimulus type into its own file.
Check the Data
using all three of these methods
Head Plots
Plot the head maps for the time ranges of interest
Waveforms
Plot the waveforms of the averaged data
Grand Grand Averaging
Averaging all of the data of one type together. such as all face data or all scene data
R E S O U R C E S