Sunday, October 13, 2013

EEG Hacking Begins

So you're interested in doing some EEG Hacking?  Me, too!  I've been doing EEG hacking for a few months now, and I'd like to share what I've learned.  I'm not quite sure where to begin, so I'll start with some of my favorite links on how I learned about EEG.  None of these links is entirely satisfying, so I'll eventually replace these links with my own content...but until I'm able to write it, we're stuck with what we find on the Internet.

A Sporty Blue EEG Cap 

Of course, everyone starts with the wikipedia page.  It's an OK page.  It's too long to be a good introduction.  I do find its discussion of the history of EEG to be interesting (it's 90 years old!) and I like the discussion of the different EEG frequency bands.  Sadly, it's not too helpful on how to actually do an EEG.

EEG Setup:

There's no good, simple description of how to do a very basic, hacker-style EEG.  I'm going to have to fix that.  Until that time, we're stuck with others' descriptions.

Here's a decent link that talks about a number of aspects of EEG, but I like the pictures of the electrodes, of the electrode placement, and of typical EEG artifacts...especially of eye motion.

The BCI2000 folks also have a lot of good information.  Here's a basic on electrodes, placement, and typical signal artifacts.

Typical EEG Signals:

The links above talked about about some typical signals, especially of "artifacts", which are the undesirable signals that get picked up by the EEG system.  These artifacts are usually not associated with brain activity, which is why they are considered bad.

Actual brain signals in EEG are often discussed and analyzed based on their frequency content.  These are the so-called "Alpha waves", "Beta waves", "Theta waves", and such.  The Wikipedia page above discusses these different frequency band.  So does the link below:

Another way of discussing EEG signals is by the shape of the waves, not just their frequency content.  This is the "morphology" of the waves.  These are the "Sleep Spindles" and "K Complexes".  Some of the morphologic features in EEG signals:

Finally, here's a more formal (and detailed!) discussion of some normal types of signals that you might see in an EEG.  It spends a lot of time discussing alpha waves.


  1. Your blog is a diamond mine for those who interested in EEG hacking.
    I have just started. Reading your blog from the beginning :)

  2. Chip, thank you for consolidating wealth of information for us all. Appreicate all your hardwork. regards, ZK

  3. I'm starting in the EEG hacking and I find your blog really helpfull as a path to follow in this amazing topic. Thanks a lot to share, best regards from Spain.


  4. Hi, i was wondering if i could possibly interview you for a personal project i am doing, and if so how i may contact you