The Muse 2 has advanced EEG sensors that collects brain wave information to be used for meditation and being calm. I used an osc application to get data direct from the sensor. Then used that data to feed into the parameters of a visual from a past project. 

There was no way to know how accurate the device was with brainwaves, but I observed and found out variation in data transmitted when I looked at the picture of my dog for long vs when I was talking to my friend about something funny. No comments on how reliable it was but was a fun experiment regardless.