Hi Jackson,
This fourth (out of four) type of concentration seems to be momentary concentration. It mentions the rise and fall of the aggregates, not the sense bases, but sense bases and aggregates are just different ways of classifying experience, and both rise and fall.
http://www.accesstoinsight.org/tipitaka ... .than.html"And what is the development of concentration that, when developed & pursued, leads to the ending of the effluents? There is the case where a monk remains focused on arising & falling away with reference to the five clinging-aggregates: 'Such is form, such its origination, such its passing away. Such is feeling, such its origination, such its passing away. Such is perception, such its origination, such its passing away. Such are fabrications, such their origination, such their passing away. Such is consciousness, such its origination, such its disappearance.' This is the development of concentration that, when developed & pursued, leads to the ending of the effluents.
Mike