That makes sense to me. There's a causal link between ambient air CO2 levels and cognitive changes, but the air in front of your face, which you breathe, doesn'

That makes sense to me. There's a causal link between ambient air CO2 levels and cognitive changes, but the air in front of your face, which you breathe, doesn't play a role... A lack of direct study might make "in front of your face" numbers harder to interpret in absolutes, but relatively speaking I do think that's the number which matters more. Whole-room analysis is just a proxy for the air in front of your face.