I just added the DAN report as well to my original post.
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maybe you should read them again?
"We determined psychomotor and mental performance impairments during exposures to air and to normoxic N2-O2 mixtures at 6, 8.5 and 11 bar ambient pressure in 10 subjects. In this pilot study 3, 3 and 4 subjects were studied at 6, 8.5 and 11 bar respectively, and N2-O2 and air exposures were not randomized."
"A rise in O2 pressure to 1.65 ATA, or in N2 pressure to 6.3 ATA at a constant high PO2 level, caused a significant decrement of 10% in mental function but no consistent effect on psychomotor function."
What am I missing?
There is no study which shows that at our typical exposures in the 20 to 30 meter range (i.e. N32) O2 is narcotic.
The quoted N2 partial pressure is about the same as air at 230', so I suppose it doesn't provide any support for the idea that nitrogen is narcotic within recreational depths either.
(but we do know from personal experience we get narced shallower than that).
That is a fair comment (but we do know from personal experience we get narced shallower than that).
I never thought I could get narced at 21 meters till the first time I got narced at 21 meters and that I only noted the first time in a cave when I became task loaded in an unfamiliar area (Setpoint of 0.7 pPO2 on rebreather).
I do not think we would notice/perceive narcosis in a recreational dive Open Water and OC unless we were asked to perform some task and the environment is demanding (low vis., bit of current, light, use different tools, store them, take them...).
normally people cite publications to prove points, rather than citing a lack of publications to prove them, but your way seems much easier since it doesn't require any research.
That's where CO2 narcosis becomes involved. That's why adding a little O2 and reducing a little bit of N does nothing to fix narcosis experienced when working.