SPSS & Statistics
We use SPSS to calculate statistics for our data.
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Analysis
Amplitude Averaging The last step in the data analysis process is to make a matrix of the average amplitudes. For each cell, the...
Average Waveforms
Here, we plot the waveform of the averaged data using EEGLAB. For example, we may want to plot the average waveform of the scene stimuli...
Head Plots
Headplots allow us to spatially visualize the neural activity for a given time range. We look at these to make sure the plots look like...
Averaging Trials
For each stimulus type for each person, we want to average all of the trials together. We now switch from using EEGLAB to using...
FieldTrip
FieldTrip doesn’t have a graphic user interface (menus you can click). It is instead a set of functions. Most of these functions have...
Sorting by Stimulus Type
Now, you should separate out each different stimulus type into its own file, and save that file. I give these file names with the subject...
Example Components
There are several things to look at when determining whether or not to reject a component. None of these are hard-and-fast rules; they...
Component Rejection
Once we run ICA, we can remove the noise components. This section explains how to use the SASICA plugin to identify and reject noise...
Baseline Removal
The 250 ms before the stimulus is used as a measure of “baseline” activity. For each epoch (time window before & after the stimulus), the...
Epoching
When the data is imported, it is one continuous segment. Epoching is extracting a data segment from just before and after each stimulus....
Independent Component Analysis
Each electrode receives signals from a combination of various neural and non-neural sources, such as eye movements, muscle movements,...
Filtering
In order to understand filtering, you need a basic understanding of Fourier Transforms. Read An Introduction to the Event-related...
Fourier Transforms
French mathematician Joseph Fourier introduced the Fourier Series in 1807, and today the Fourier transform is used a wide variety of...
Delete or Interpolate Bad Channels
Deleting Channels We may want to delete bad channels. For example, we may delete channels around the face and neck that are receiving too...
Collecting Data
Make sure to turn WiFi off on the computer before opening NetStation Acquisition. Instead of collecting your own data, you can also use...
Channel Locations
If you’re using Dr. Thom’s dissertation experiment data (AA & AB), you need to choose the file that specifies the channel locations for...
Converting & Importing Data
Convert to .raw Once you record the data, it will be saved as a .mff file. Find this .mff file and convert it to .raw using Netstation...
Re-reference Data
When the data is taken, it is referenced off of a reference electrode in the center of the scalp. We need to convert it to an average...
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