Shallow breathing vs. Deep breathing (Dopamine)

[Morning Dew]

Hi friends,

After reading all the stuff about serotonin and dopamine and breathing I am still kind of puzzled which triggers which?

If I understand properly shallow breathing induces the blood CO2 levels which decrease Dopamine levels making us sluggish, tired and even depressed.
On the other hand if one breaths deep but calm the Dopamine and Serotonin levels increase due to good blood O2 levels and the stress hormones like Cortisol decrease (the Amygdala calms down) causing one to feel calm and even joyful depending on the Dopamine levels.

Dopamine also gets produced when we "like" or "cling" to stuff! So Dopmaine ain't entirely good as it seems, or in this case we can aspply the Middle Way and keep the Dopmaine levels in moderate amounts   We need Dopamine but not that much!

Does shallow breathing cause halucinations like spirit voices, seeing colors and forms, etc ... ?
Is deep over-breathing as bad as shallow breathing? That is what I do when practicing Ki-breathing, which helps me if I start to procrastinate with my meditation practice, it kind of jump-starts my Dopmaine and Serotonin levels I guess and makes me feel better, stronger.

When in Shamatha I used to breath shallow almost totaly silent so I could notice my thoughts. Even though I was not stressing my body I was stif in a psychological way, watch, observe don't breath kind of way, and this made me sleepy and even depressed.

I am trying to explain the significance of Deep Breathing vs. Shallow one to a friend but have problems explaining it. Western mind would like to hear stuff about brain chemistry etc ...

Any one care to help me here  
Thanks!

[mik1e]

"Deep breathing"  and "shallow breathing" are equivocal terms. They may describe both different kinds of pranayama (qi-gong), which can change the processes in the body quite seriously, and just variations of "normal" breathing (which has weak enough influence on the body and nervous system). If you want to get correct answer, please specify what you are asking about.

[Marina_J]

Diaphragmatic breathing, abdominal breathing, belly breathing, deep breathing or costal breathing is the act of breathing deep into one's lungs by flexing one's diaphragm rather than breathing shallowly by flexing one's rib cage. This deep breathing is marked by expansion of the stomach (abdomen) rather than the chest when breathing.

[alphawavedave]

I feel it is much better whilst meditating not to interfere with breathing, simply observe allow it to be as it is.

However as a preparation exercise before the meditation it may be helpful to do some form of diaphragmatic or whole body breathing. Here is the process I personally use:

Start the in-breath with an expansion of the lower abdomen, allow this expansion to move through belly whilst subtly bowing the the spine outwards (This bowing of the spine acts as a wave from base to neck). As the in breath comes to completion include an expansion of the chest.

For the exhalation actively focus on relaxation allowing the breath to be like a sigh of releaf. The breath once again follows a very subtle wave of the spine going in the other direction. Take a little longer on the out breath making sure the lungs are as empty as is reasonable, this way the following in breath kicks in automatically.

After breathing this way for about 6 breaths let go of breathing techniques and simply observe.