More reference material I found, this by Ajahn Lee.
Another instance of Wrong Concentration is when — after you've begun practicing to the point where you've attained threshold (upacara) concentration — you then stare down on the present, focusing, say, on the properties of breath, fire or earth, forbidding the mind to think; staring down, getting into a trance until the property becomes more and more refined, the mind becomes more and more refined; using force to suppress the mind until awareness becomes so dim that you lose mindfulness and alertness and all sense of the body and mind: Everything is absolutely snuffed out and still, with no self-awareness. This is called the plane of non-perception (asaññi-bhava), where you have no perception of anything at all. Your awareness isn't well-rounded, your mindfulness lacks circumspection, and as a result discernment has no chance to arise. This is called Wrong Concentration, Wrong Release, a mental blank — no awareness of past, present or future.
http://www.accesstoinsight.org/lib/thai ... peace.html" onclick="window.open(this.href);return false;
This clearly has to be distinguished from the following:
"There is the case, Ananda, where the monk would be percipient in this way: 'This is peace, this is exquisite — the resolution of all fabrications; the relinquishment of all acquisitions; the ending of craving; dispassion; cessation; Unbinding.' It's in this way that a monk could have an attainment of concentration such that he would neither be percipient of earth with regard to earth, nor of water with regard to water, nor of fire... wind... the dimension of the infinitude of space... the dimension of the infinitude of consciousness... the dimension of nothingness... the dimension of neither perception nor non-perception... this world... nor of the next world with regard to the next world, and yet he would still be percipient."
http://www.accesstoinsight.org/tipitaka ... .than.html" onclick="window.open(this.href);return false;
Percipient of what?
Sariputta:"'The cessation of becoming — Unbinding — the cessation of becoming — Unbinding': One perception arose in me, friend Ananda, as another perception ceased. Just as in a blazing woodchip fire, one flame arises as another flame ceases, even so, 'The cessation of becoming — Unbinding — the cessation of becoming — Unbinding': One perception arose in me as another one ceased. I was percipient at that time of 'The cessation of becoming — Unbinding.'"
http://www.accesstoinsight.org/tipitaka ... .than.html" onclick="window.open(this.href);return false;
Now what I find pretty interesting is "and yet he would still be percipient" (saññī) whereas the "wrong concentration" described above is said to be "asaññi" = not percipient? So that would seem to be a key to distinguish these states.
Doing some dictionary research:
Asaññin (adj.) [a + saññin] unconscious D i.54 (˚gabbhā, cp. DA i.163); iii.111, 140, 263; It 87; Sn 874.
Saññin (adj.) [fr. saññā] (f. saññinī) conscious, being aware of ( -- ˚), perceiving, having perception
"Saññā (f.) [fr. saŋ+jñā] (pl. saññāyo and saññā -- e. g. M i.108) 1. sense, consciousness, perception, being the third khandha Vin i.13; M i.300; S iii.3 sq.; Dhs 40, 58, 61, 113; VbhA 42. -- 2. sense, perception, discernment, recognition, assimilation of sensations, awareness M i.293; A iii.443 (nibbāna˚)
http://dsal.uchicago.edu/dictionaries/pali/" onclick="window.open(this.href);return false;
And DN 1 Brahmajāla Sutta describes "Doctrines of Percipient Immortality (Saññīvāda)" and "Doctrines of Non-percipient Immortality (Asaññīvāda)"
http://www.accesstoinsight.org/tipitaka ... .bodh.html" onclick="window.open(this.href);return false;
"When one thing is practiced & pursued, ignorance is abandoned, clear knowing arises, the conceit 'I am' is abandoned, latent tendencies are uprooted, fetters are abandoned. Which one thing? Mindfulness immersed in the body." -AN 1.230