Theory 77/Hiccups/Threshold lens
Hiccups Stop on CO2
The claim
Hiccups cease above a threshold in arterial CO2, which is why breath-holding terminates them.
01Mechanism
Raised CO2 resets the reflex arc by suppressing the vagal trigger.
02Prediction
Cessation should track CO2.
03Refutation
Cessation tracking attention would remove the chemical term.