By Bio Share 
Top of forehead: for sleep, meditation, head posture and activity, etc.
Side of forehead: for alpha wave, left or right brain activity, etc.
Center of chest: HRV, breathing, body posture and activity, etc.
Slant over temple: cool Star-Trek 7-of-9 look, alpha wave, eye movement, etc.
Behind ear: cool sci-fi star crew look.
Both sides of forehead: double cool, left & right brain compare.
upper arm: body activity, SCR/GSR/EDA, etc.
Wrist, top side: hand activity, SCR/GSR/EDA, etc.
Wrist, bottom side: hand activity, SCR/GSR/EDA, etc.
