Revised January 17, 2019
1. Everything that we experience comes through six “doors” or “āyatana” we have to the outside worlds: eye, ear, nose, tongue, body, and the mind. Through those six doors we can see pictures, hear sounds, smell odors, taste food, feel things physically by touch, and be aware of concepts (say, mundane things like remembering past events or make plans about future events, or think about a black hole in the middle of the universe or a mathematical concept).
- The six sense faculties (and the corresponding six external “āyatana” which are rupa, sadda, gandha, rasa, pottabba, dhamma or visuals, sounds, smells, tastes, touches, and concepts) are what the Buddha called “sabba“, or “everything”. These are 12 āyatana (6 internal and 6 external).
2. All those sense experiences are done with citta or thoughts. But this is probably not a good translation. We normally associate a “thought” with an idea or one visual event, etc., a moment of “experience”. But citta is very fast and no one can experience a single citta which lasts a billionth of a second or less; see, “Citta and Cetasika – How Viññāna (Consciousness) Arises“.
- Don’t be fooled by the title of that post. It has a simple description of how the “mind” puts together all six sense inputs to give the illusion that we see, hear, smell, taste, touch, and think all at the same time (at least start reading at #3 there).
- It is a good idea to also read the posts, “Amazingly Fast Time Evolution of a Thought (Citta)” and “Viññāna – What It Really Means” first.
5. When we look at an object, the “eye” generates visual consciousness (cakkhu viññāna): Comprehending what is seen is accomplished via a series of very fast thought processes. There are billions of thoughts per second, so each citta or thought moment is billionth of a second. Let us see how the mind “sees” an object in a series of very fast “snapshots” alternating between the “eye” and the “mind”:
- The “eye” captures a snapshot of the object and the brain transfers that captured information to mind: that process takes 17 thought moments or cittā (let us abbreviate it as TM); this series of TM is called a “sense input citta vithi” (or pancadvāra citta vithi). Next the mind analyzes that “imprint” with three citta vithi that involve only the mind. These latter “mind-only citta vithi” (manōdvāra citta vithi) are shorter, around ten TM, and try to discern what the object is. It may first try to discern the color of the object for example.
- Then the “eye” takes another snapshot and transfers that “imprint” to the mind, which in turn receives it in a pancadvāra citta vithi containing 17 TM, analyzes that in 3 more manōdvāra citta vithi containing about 10 TM, and makes better sense of the color. This “back and forth” process goes on until the object is determined.
- This process is slowed down only due to the time needed for the brain to put together the information captured by one of the five sense faculties (pancadvāra), for example, the eyes. This time is of the order of 10 milliseconds; see, “What is a Thought?“. Thus there can only be about 100 (600 if they are processed in parallel) or so “sense events” per second; since science show that the brain has different regions for processing different sense inputs, the latter number (600) is probably right.
6. Since these citta vithi run very fast, once the brain sends an “information packet” to the mind it is processed very quickly, within billionth of a second. Thus the process is slowed down only by the brain. Still, everything about the object is grasped in a small fraction of a second.
- Now, many of you may be thinking, “this looks like some far off theory made up by someone”. The Buddha said he experienced everything that he taught. Phenomena in this fast time scale are discernible only to a Buddha.
- Once the Buddha explained the key aspects to Ven. Sariputta, it was Ven. Sariputta and his group of Bhikkhus that developed the Abhidhamma, where all these details were worked out. It took generations of bhikkhus to develop the Abhidhamma to the final form that was recited at the Third Sangāyanā (Buddhist Council) and was written down in the Tipiṭaka in 29 BCE (we know that there were many Arahants before 100-200 CE; see the timeline in “Incorrect Thēravada Interpretations – Historical Timeline“). For us, the truth of these minute details become apparent as all observable phenomena are EXPLAINED using all three forms of Dhamma in the Tipiṭaka: Sutta, Vinaya, and Abhidhamma).
7. As all this information comes in, the mind recognizes the object; this is saññā or perception. Based on that recognition feelings (vēdanā) are generated (for example when we see a friend we generate a happy feeling; if it is someone we don’t like, it is a unhappy feeling, etc).
- Once everything about the object is grasped, then if it is an “interesting object”, the mind may start its own “wheeling around” process: the “pati +iccha sama+uppāda” or Paṭicca Samuppāda process leading to the accumulation of saṅkhāra: see, “Paṭicca Samuppāda – Introduction“, “Nibbāna – Stopping Saṃsāric Vehicle, Ariya“, “Saṅkhāra, Kamma, Kamma Bīja, Kamma Vipaka“, and other related posts. All these tie up together, but one needs to be a bit patient since there are many inter-coupled concepts.
8. Thus experiencing a visual object in the above example generates all kinds of mental phenomena: vēdanā, saññā, saṅkhāra, and during this whole process we have the viññāna or citta flowing. Viññāna is the momentary consciousness, a citta. In the above example, it alternates between visual consciousness (cakkhu viññāna) and the mind consciousness (mano viññāna).
- The baseline state of a citta, i.e., when the mind is not looking at an external object or thinking about it, is called “bhavaṅga“. Here we do not “feel” anything, for example when we are in deep sleep. The mind falls back to the bhavaṅga state even in between pancadvāra citta vithi.
9. Same kind of process happens with any of the five physical senses (the “back and forth switching” between the sense faculty and the mind). When someone is just remembering a past event or planning something, those are exclusively mind processes (only manōdvāra citta vithi take place).
Now let us look at some details on how the mind processes all the “signals” from the real world where multiple “signals” come in.
- When we watch a movie, what happens is the projector projects about 30-50 static pictures per second on the screen; a movie is a series of static pictures. When the projection rate is above 30 frames a second or so, our eyes see a continuous movie, not individual frames. Thus even though cittā run at billions per second, we do not “experience” them individually, not even close.
- This fast rate of citta vithis (which, as we saw above run at about 100 citta vithis per second) also make it possible to perceive all six inputs from the outside world “simultaneously”; at least we experience them as “simultaneous”. For example, we can be watching a movie and enjoying some popcorn; so we see and hear the movie, and taste popcorn and feel the popcorn cup, and also may be thinking about something related to the scene on the screen; all at the “same time”.
- Citta vithi just alternate among the six sense inputs; it is possible only because there are hundreds of citta vithi per second. Since it happens so fast, we experience them all as “simultaneous”, just like the static pictures projected at a fast rate on a movie screen are perceived as a continuous “movie”.
- Not only that, but the mind can ignore a multitude of “signals” that are of no interest to one’s own habits (“gati“) or cravings (“āsavā“). And those depend on the individual. Two friends could be walking on the street, and one (woman) stops abruptly and starts looking at a dress on a shop window. The other (man) looks at it, shrugs, and wants to move on; he would not have even noticed it.
10. As we saw, information to the mind comes via the brain. All five physical sense inputs (vision, hearing, smell, taste, touch) come through the brain. Thinking about concepts involves the brain too (those involve only the manōdvāra citta vithi), and that happens much faster compared to the processes associated with the five physical senses; we will discuss that later.
- When someone gets old, the brain starts functioning less efficiently; see, “Manomaya Kaya and Out-of-Body Experience (OBE)“. Or, the brain may get damaged due to a kamma vipāka; for example, getting Alzheimer’s disease is a kamma vipāka.
- As the body gets old, various other body parts also start functioning less efficiently and are also vulnerable for many kamma vipāka to come to fruition. Kamma vipāka are not deterministic; they come to bear fruit only when conditions become suitable (see, “Saṅkhāra, Kamma, Kamma Bīja, Kamma Vipaka“). Thus meditation and regular exercise help keep both the body and the mind (through an efficiently working brain) in good condition.
11. In any case, the mind goes to the “baseline or dormant state” called “bhavaṅga” even in between these citta vithi. When the mind is fairly inactive, say when someone is dozing off, the mind is mostly in the bhavaṅga state. When someone is unconscious or in deep sleep, it is in the bhavaṅga state for the whole duration. When seeing a dream, the mind is active.
- Even when citta vithis run at a fast rate of about 600 per second (say, while watching a movie or while playing a competitive sport), the mind drops to the bhavaṅga state while the brain is processing those “10 millisecond information packets”, as discussed above.
- The above discussion is all about receiving information from the outside world and then getting attached to “things” (“taṇhā“), generating mano saṅkhāra, etc.
12. Based on that process, we may decide to take further action too, either verbally or bodily, thus generating vaci saṅkhāra and kaya saṅkhāra: We may speak or do some physical activity. All those are done with the mind too, and each action done with thought process or citta vithi.
- This is why the Buddha said, “manō pubbangamā dhammā, ,,,,”, i.e., “mind precedes everything that we do…”. We cannot even lift a finger without generating a citta vithi, i.e., without the initiation by the mind. The physical body, with the brain acting as a “sophisticated control center”, helps the mind to achieve whatever physical activity it wishes; see, “Neuroscience says there is no Free Will? – That is a Misinterpretation!”.
Further reading: “A Comprehensive Manual of Abhidhamma”, by Bhikkhu Bodhi (2010). This book has summarized citta and cetasika very well. But discussions on Paṭicca Samuppāda or anicca, dukkha, anatta are not correct.
Next, “What is Consciousness?“, …….