В книге Pa-Auk Sayadaw "Mildfulness of breathing and Four Elements Meditation" наткнулся на следующий абзац:
At this stage you will reach either access (upacara) or absorption (appana) concentration. Access concentration is the concentration close to and preceeding jhana. Absorption concentration is the concentration of jhana.
Both these types of concentration have the patibhaga-nimitta as their object. the difference between them is that in access concentration the jhana factors are not developed to full strength. For this reason during access concentration bhavanga mind states still occur and one can fall into bhavanga (life-continuum consciousness).
Что это за состояние ума - bhavanga (life-continuum consciousness)?