Well ... if galvanic skin responses EEG headbands can give a recording of two hours of sleeping with half an hour of a dreaming (a nightmare in fact, very scary dream!) showing very strange signals - starting with about 10 minutes of very high and irregular spikes only at the right forehead lobe (FP2), followed by another 15 minutes of the same kind of signals (that I was unable to get when awake) now totally synchronized at the four channels, ending only at FP2 again (and going back to normal - when I got awake) ... then I think that Muse is a very good "galvanic" EEG headband :o
As a side note, when doing regular recordings with Muse when awake (both actively thinking and focused or when getting calm or trying to meditate) I allways get higher amplitude signals at the ears TP9 and TP10 compared to the sensors at the forehead FP1 and FP2. In that recording of a dreaming state all four channels went to much higher and all about the same amplitude - funny !
I believe that if galvanic skin potencials occurs, they should be considered as noise and I suppose that's why the REF and DRL sensors are there, to supress them - it would be very nice if someone of the Muse Team could confirm or explain this point.
I will try to make a video of this EEG nightmare recording telling simultaneously what was happening (at least what I can remember) during the dream, very soon, and share if anyone interested.
BTW: before anyone ask me ... yes, I enabled --dsp during recording, and checked when replaying all relevant indicators (is_good, quantization, horseshoe. all = 1 almost all the time, and mainly accelerometer showing no movement of the head - when it shows I disregard that part of the EEG.
As a toy to fool my nieces and nephews I developed a small windows program using only eye blinks and jaw clenches, asking them "... wich LED number do you want me to turn ON or OFF with my mind ? may be one at a time, or all ON or all OFF at once. " .... they get crazy with the precise results :o