Processing unit 301 is {HEAD ~ a microprocessor} that digitizes {TAIL ~ physiological data} and then processes it into physiological responses that include but are not limited to thought, engagement, immersion, physical engagement, valence, vigor and others 
Processing unit 301 is { HEAD ~ a microprocessor } that digitizes { TAIL ~ physiological data } and then processes it into physiological responses that include but are not limited to thought , engagement , immersion , physical engagement , valence , vigor and others
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH