Basic EEG processing
Basic EEG processing allows you to re-reference and do high-pass filtering of your selected EEG data recordings.

Slew limit

You can set a slew rate limit to control the EEG signals between successive samples, up to a maximum value. Large voltage step changes from one sample to the next sometimes occur due to electrostatic discharge from the subject (participant), headset movements, or other artifacts. The effect of voltage step changes on filtered signals, and fast Fourier transform (FFT) epochs can artificially persist for a long time after the event. Setting a maximum slew rate limits the extent of step changes and reduces its impact without significantly affecting the EEG signal components.
The default slew rate in Analyzer is 30 microvolts. However, you can enter any positive value here.

Re-Referencing

Data processed by Analyzer can be re-referenced to an aggregate of all the data selected. The available aggregate functions are:
  • Mean
  • Median
  • Interquartile mean
  • None (deactivates re-referencing)

Filter Coefficients

Default values are set for you. However, you can change these values if you want to.
If you do not know what you are doing, please use the default values. The default values are shown below.
Once you have set the values for basic EEG processing, click on the Start button. Analyzer will then process your selected data recordings.

Results

While your data is processing, the results page will open. The results page provides information about the jobs processed in Analyzer: including Job Name, Date Created, Status, and Actions.
Once Analyzer has finished processing your data, its status will change from Processing to Complete.
If the status doesn’t say ‘Complete’ within a few seconds, click on the Refresh button at the bottom right-hand corner of the screen. You can download the completed data as a ZIP file and save it locally. To do this, click on the Results button.