I created software for combining different signal sources - including EEG, GSR and pulse sensor, which let Rafał build his interactive composition, meant to be played on human emotions.
For EEG data we used Emotiv EPOC and written a data transceiver which outputs OSC messages - it's open source and available for free: szymonkaliski/EEG2OSC.
Pulse sensor and GSR were using e-Health Arduino platform: https://www.cooking-hacks.com/documentation/tutorials/ehealth-biometric-sensor-platform-arduino-raspberry-pi-medical
Both hardware sensors were outputing OSC at the end of processing pipeline, and Rafał wrote his own Max/MSP code to generate music.