Thanks for the reply and the novel ideas: that "trader apnea" and stress-induced breathing interruption could lead to poor mental performance.
(Side note: Sleep apnea is a common medical condition, where a person does not get enough oxygen while sleeping because the trachea collapses or is obstructed. Symptoms: snoring or snorting; restless sleep; waking frequently (often without knowing). It stresses the heart and can have other health consequences. The solution is a small CPAP or variable-speed BPAP machine, that pumps air into the lungs via a nose-mouth mask. It's also helpful when lungs are congested, or one has bronchitis or asthma. Look into it if you snore.)
Anyway, the variable-motor speed BPAP gives aural feedback about breathing interruptions, speed and depth. Disadvantages related to trading are: it takes some space, one needs to connect and disconnect a mask; it interferes with phone use and conversations. Advantages are it may prevent you from nodding off -- dangerous if holding a mouse.
Thanks again.
