Yes. The initial description is very good.
“The manasikāra cetasika are in each and every citta, and they are to incorporate all past memories.”
– That is correct too.
“This makes complete sense for a manodvara citta vithi since the mana indriya is active during that time. What I’m not clear on is how the manasikara cetasika in a pancadvara citta vithi operates:
The mind can only process one citta vithi at a time. That means while the first 17 citta (pancadvara) arise, the mana indriya should not be able to make contact with the mind.”
– Of course, this is where some clarification is needed.
1. Pancadvara means “five doors.” These are doors to the external world.
– But it is ALWAYS the mind that experiences any arammana coming through any of those doors.
– For example, cakkhu vinnana is just one citta at the beginning of a cakkhudvara citta vithi. That citta, as well as 16 others cittas, are experienced by the mind.
– Thus, cakkhu vinnana just indicates “through which door” the experience (more correctly arammana) came in.
2. The post “Citta Vīthi – Processing of Sense Inputs” describes this process starting with #2.
– All 17 cittas in even the pancadvara citta vithi arise in the mind.
– Then, #6, under the heading “The Simile of Tasting a Mango,” provides an analogy.
3. Earlier you correctly stated, “When the mind comes in contact with a sense input (arammana), let’s say a sight, the image is received by the eye and then transferred to the visual cortex in the brain which processes it to a suitable rupa which, in turn, is then transferred to the mind.”
– However, that does not happen in “one shot.”
– The eyes/brain capture and analyze only a brief moment (about 10 ms, or one-hundredth of a second duration according to modern science). Thus, the first snapshot may only capture a blurry image of the object.
– It would take several such snapshots to accumulate until the mind can “comprehend/fully see) that object.
– Still it would take three manodvara citta vithi following a single pancadvara citta vithis to fully grasp a single snapshot; see #9.
– In other words, it takes four citta to fully process a single snapshot of the object captured by the eyes/brain.
4. Also, note that the mind processes those citta vithi VERY fast, compared to the time taken by the brain to process a single snapshot.
– The brain takes about 10 ms, or one-hundredth of a second, as I mentioned above. When that “information packet” comes to the mind (via cakkhu pasada rupa), the mind processes that within billionth (one-billionth) of a second.
– Thus, if we assume the time taken for the mind to process the four citta vithi to be 1 unit, the time taken by the brain to compile that “data packet/snapshot” would be ten million units!
– That shows how slow the brain is compared to the mind.
5. Anyway, so the mind accumulates several such snapshots. The manasikara cetasika “keeps track” of those previous snapshots and helps the mind get the “full picture.”
– Of course, all that happens within less than a second.
– Only a Buddha can see such details!
6. The situation is even more complex because other sensory inputs could be coming through the other “doors.”
– But the mind can “sort them out into the correct categories” with the help of the manasikara and cetana cetasika.
7. I have tried to provide further details in the following two sections:
“Essential Abhidhamma – The Basics”
“Our Two Worlds – Rupa Loka and Nāma Loka”
– It will take some effort to go through them. Some posts may be more relevant than others. So, it would be a good idea to print them and organize them. Each person understands things differently.
Of course, feel free to ask more questions from those posts. You are on the right track!