Amplitude values

Hi, I am a german student of psychology, and we have just done an eeg-experiment (concerning the alpha band) with Muse. We used Muse, Muse Monitor and the software “Processing”. What is unclear are the units of the data. As I can see in the technical data of muse, the amplitude raw data come in microvolts within a range up to approximately 1682 microvolts. In the eeg-literature I can find a mean range up to approximately 100 microvolts for the amplitudes. So how do I understand the Muse-data with ten times as high amplitudes? Can anyone help?
Regards, Oliver

1682.815uV is the maximum range of the sensor. You’ll only see it go this high if you’re looking at EMG interference from things like eye blinks. The brainwave data will be much much lower.

You should also note that the data will be centred at around 850uV, so if you want it centred around zero, you can normalize it.

so is it a matter of “tuning” the muse or a matter of the output software? what I don’t understand is: neurons are firing with certain electrical output. I don’t have a clue, why one instrument would measure 50 microvolts and the other one 500?

It’s just an electric circuit thing. They’re both measuring the same thing, it’s just presented offset from different values.

as I am no electro-technician I try to learn and understand what’s going on, so forgive my asking :wink: I learned today, that due to the small value of output eeg needs amplification and so I think some eeg will put out ten time higher values. Is that right, and where is the amplification of muse located? in the electrodes or in muse monitor? thanks for your patience :slight_smile:
And, ah, should we use Muse dry or better with some conductive gel? What are the experiences?

It’s all done in the hardware.

Regarding Gel, no dry is fine.