So how exactly do I capture my brainwaves on my EEG, and what are the parameters I use when doing so?
This information is important. The accuracy of my brainwave data is central to my entire project. Is my data as clean as it can be? Or is it contaminated with artifacts from muscle movements, eye movements or tensing my face really hard?
I’m going to do my best to lay out the answers in this post. Note: this is kind of a nerdy post. It may only appeal to people interested in brainwave data. So if this isn’t you, don’t feel bad to just…click away…
Capturing brainwave data that’s clean enough to use on a consistent basis has been one of the most challenging aspects of my project. At times it’s been so excruciatingly painful, that it’s made me question if I can continue.
Over the 28 months I’ve been recording (as at September 2022), I’ve had to discard probably three times as many sessions as I’m able to use, because of bad data (literally hundreds of sessions). This has been disappointing on a regular basis – especially when I feel it was a powerful session – and I just can’t use it.
I’ve had months straight with minimal issues, and I’ve had months straight where I’ve literally been ready to throw the towel (these situations have often taught me valuable lessons about myself that I won’t go into there, so it’s not without purpose).
Thankfully I’m as stubborn as an ox – so no matter how hard it is and no matter how long it takes, I WILL NEVER GIVE UP.
Introducing my arch nemesis: bad brainwave data.
Bad data, in the form of false gamma, can come from anywhere. Voluntary and involuntary muscle movements (big and small), eye movements, jaw clenches, yawns, breathing, as well as (probably) visual processing – basically any kind of movement at all.
I can only control what is within my ability to control – and that is my voluntary movements, as well as my environment.
I record my mindful drawing/EEG sessions in ONE spot in my house – I have since the beginning of my project. My apartment is tiny, it’s not like I really have many options, but it’s the one spot with minimal electrical interference which can show up as ‘noise’.
During my sessions, I have everything I need with me, so I don’t need to move during the session. I breathe lightly, I don’t move my head, tongue, jaw or tense my brow, or any part of my face. I’m basically frozen during my session (yes this is as awkward as it sounds). I do however blink lightly once every few minutes and move my eyes very smoothly, and slowly (there are no jerky eye movements) as I’m drawing.
The level of light where I draw is pretty much the same (it’s either good natural light, or I don’t draw), my drawing paper is always around 30 cm away from my eyes so my eyes aren’t focusing at different distances, and my ‘concentration face’ is the same – that is, I try to maintain a gentle, relaxed face.
I also only use data that is within a range of 50 microvolts on the RAW data of my EEG. If it falls outside of this, I chuck the session. I have been advised that these are the parameters to consider clean enough to use.
Visual processing, or some type of undetected muscle movement is NOT the cause of my high gamma. Here’s why.
In every one of my sessions, my eyes are open and visually processing – so physically, I’m doing the exact same thing – yet the results are often vastly different. I have many sessions with low, flat gamma, and some displaying very high gamma.
There is also nothing ‘artifact-wise’ that explains my gamma brainwaves gradually (but clearly) rising over the course of 28 months. It’s rising because of my conscious, consistent effort. This high gamma is coming from the inside of my brain. I can feel it.
The only thing I do ‘clean up’ after a session, is a few blinks – which equates to between 1-2% of data. If it requires any more cleaning than this, I’ll scrap the session. If I happen to have a blinky session (I’ve had a lot), I’ll scrap this session also.
Cleaning up between 1-2% of data (which is seen as 1 second spikes in the RAW data) barely changes the final reading – or I wouldn’t do it. I also keep the original files of every session.
There is also no sweat, make up, or oils on my face as I am meticulous about removing this before each session – as this too would interfere with the RAW data. I also clean the sensors of my Muse once in a while with alcohol wipes.
I hope that sheds some light on how I capture my data, and how vigilant I am about minimising the artifacts and noise as best I can.
I’ll end this post by saying my Muse EEGs have been excellent for my research – in fact my project wouldn’t exist without them (I say ‘them’ because I’ve used several). But at this point I’m really looking forward to the day I can access a more sophisticated EEG…..I have so many questions and such a deep hunger for this knowledge.
But for now? I’ll just keep on using my trusty Muse while working out in the frequency gym, and keep on gather data as best as I can.