umaf44•1mo ago

Took me 6 months to realize my EEG headset was picking up muscle noise not brain signals

I was getting these clean looking waveforms from my OpenBCI headset during what I thought was focused mental math. Spent weeks tweaking filters and gain settings trying to clean things up. Then my buddy who does biomedical engineering took one look at my data and pointed out the frequency was too high for neural activity. He had me clench my jaw slightly while recording and the same pattern appeared. Turns out all those months I was really just measuring my scalp muscles twitching from concentrating too hard. Felt like a complete idiot but at least now I know what actual alpha waves should look like. Has anyone else here fallen for the same trap with consumer gear?

2 comments

2 Comments

the_uma1mo ago

You had jaw clenching showing up as clean waveforms for six months straight?

sean_park81mo ago

Actually the first 3 months were fine with my Wave setup. It was around month 4 when the clenching started showing up but the waveforms still looked textbook perfect. My dentist said that's actually common because the masseter muscles can fire strong enough to register as normal function. Had to switch to a different sensor placement and add the EMG channel to catch it properly. Those clean waveforms were deceiving me the whole time.