If anyone is interested in developing light jhana type stuff I think HRV training is actually a rather reliable and simple approach. You have to have some idea of what piti feels like already and then just use the HRV feedback as a point of reference for how successfully you're generating it. This sort of mirrors what I had considered a year or so ago about using the brahmaviharas for developing intent or effort, as metta/loving-kindness and piti are quite similar in energy, and piti is associated with viriya or effort. Piti is also basically a nimitta in its own right so it can function just fine as an internal/subjective feedback loop for developing concentration (growing in real time with attention and waning with inattention) and the first jhana is defined by the presence of piti so you're basically building a bridge directly into first jhana.
Alongside this I also think it's a good idea to use some low frequency training at FpO2, as this seems related to passadhi/tranquility, and piti arises out of passadhi. In fact I sort of think that that's the purpose of the first tetrad of anapanasati practice, since the last step in that tetrad culminates in passadhi, and then at the start of the next tetrad you shift to piti. Actually I have a theory that that's part of the reason that both anapanasati and metta meditation are good meditation objects for anyone, obviously they're both wholesome and you can't hurt yourself with them, but interestingly both breathing and loving-kindness are very good at producing heart rate variability. In addition to that, low frequency training at FpO2 should correct against striving or one's distress with practice that might result from trying to generate a very vigorous joyful energetic sensation, or engaging in a practice that is relatively taxing.
It's interesting, because for a long time I couldn't differentiate piti and sukha, for a long time what I thought was piti was actually sukha (a really pleasant physical sensation, but lacking in the vigour of piti), I think being able to differentiate this might be really important for some approaches to jhana practice, since while the two are similar and mutually reinforcing, piti seems to more reliably drive the process since it's a way of mustering up the energy needed to direct the first jhana, which is still pretty 'hands on' relative to the following jhanas. Sukha then becomes important more so in second jhana, but I think it makes more sense to master the first one first.
I mentioned this will lead to light jhana, but Culadasa says that you can use lighter jhanas to successively develop deeper ones, which makes sense to me. Jhana no matter the depth should be ideal for developing concentration. And more than anything using piti/sukha as the 'nimittas' for concentrative practice is extremely rewarding and wholesome in a general sense. You don't have to force yourself to pay attention to a phenomena quite so much when the phenomena is inherently pleasant, and it's something that flows over wonderfully into your daily life to help with your moral conduct and social relationships.
And FpOx sites relate to the orbitofrontal cortices, which are implicated in addiction and reward, and to some extent attention as well, all things useful for really changing your life and habits through mindfulness and really getting a meditation practice off the ground.
So basically (but ymmv!)
HRV = good for tracking piti
FpO2 low frequency training = good for tracking passadhi
FpO1 high frequency training = good for tracking sukha
You just have to know what each of these feel like independently and use that as your central focus, because these modalities of neurofeedback likely respond not just to these mental qualities, but also some similar or related ones (metta for HRV would also work, for example), so you have to have a degree of experience and familiarity with the related jhana factors already down to some extent, and then just use these modalities as a secondary evaluative mechanism.
In some ways it doesn't have quite the same 'wow' factor as TAGsync or Entropy training for me (aside from generating pleasurable sensations, etc). TAGsync and Entropy seem to really elegantly exercise certain modes of attention which are extremely powerful and exciting, but this approach to training just seems so gosh darn wholesome, pitisukha is a nimitta I find a bit easier to generate, and it helps a whole lot more with my conduct and the enthusiasm you need to really pursue things and make changes in your life. If my experiences are replicable you're also working directly with jhana factors, essentially, so concentration is still on the agenda.
Edited by umop 3pisdn, 10 June 2016 - 01:07 AM.