Breathing patterns in psychopathology and blood oxygen levels - Risk factor for cognitive decline?

Neuronal brain activity is assumed to be reflected by blood level oxygenation levels, also known as BOLD signal, measured with fMRI. A scan of the literature points both oxygen and carbon dioxide levels effects on The roles (O2 ; hypoxia/hypoxemia, hyperoxia) (CO2 hypocapnia, hypercapnia) in neuronal signal are complex still under investigation [1,2]. Inspiration while varying O2 CO2 air have been used investigate resting state fMRI [3].