There are many confusing terms like citta and mano which have been differently interpreted in different books. In order to clarify these concepts, I am writing a few posts in "Dhamma Concepts" section under "Mind and Consciousness" starting with:  "1. Thoughts (Citta), Consciousness (ViññÄáča), and Mind (Hadaya Vatthu) â Introduction".
1. Think about a past event that is still vividly there in your mind. You can visualize the whole âeventâ just like watching a movie; you can recall what those people looked like, what they said, etc.
- Suppose a 40-year old recalls an event where she was a 10-year old playing with her mother. She will recall the event just as it happened 30 years ago: she was young and her mother was 30 years old; it took place in her parentsâ house which does not even exist now. But in the âplaybackâ that exact same time sequence is played back with the 10-year old playing with her 30-year old mother in the same house that they lived in. It is not just a âsummaryâ of what happened, rather an exact playback showing her young motherâs features at that time, what she said, etc.
- Recently, it has been reported that some individuals have an astounding capability to instantly recall past events (during this life) in vivid detail; see, "Recent Evidence for Unbroken Memory Records (HSAM)".
2. Most scientists and philosophers believe that the memories are kept in the brain. Is this a realistic picture? They do not have any evidence to back this claim.
- How can all those details be âstoredâ in a biological membrane, ready to be retrieved at a momentâs notice? Â No one has explained a plausible mechanism yet.
3. Whatever we do with body, speech, and mind, a ârecordâ (nama gotta) gets established (âbihiwelĂ€ pihitanavaâ in Sinhala) in the kamma bhava: In the word âbhavaâ, âbhaâ means âappear and gets establishedâ; thus the act we did, i.e., kamma, gets recorded in the kamma bhava exactly the same way it happened. We cannot "see" bhava but we can see the results of bhava as "jathi".
- Not only potent kamma, but ALL memories are stored intact in the nama loka. Basically, the thought stream is recorded continuously like a movie recording and thus can be âplayed backâ; see, "What Reincarnates? - Concept of a Lifestream".
- Thus while the "fruits of kamma" are embedded in kamma bīja (seeds) in the nama loka as kamma bhava, the movie like sequence is recorded in the nama loka as nama gotta.
- Therefore, while kamma seeds in the kamma bhava can bring their results in the future, the nama gotta are just records without substance: see, "Difference Between Dhamma and Saáč khÄra (Sankhata)". Thus unlike anything else in this world (saáč khÄra or sankata), nama gotta are PERMANENT.
- This is why the Buddha Gotama could recall the exact scene that happened billions of years ago, when he received the first confirmation ("niyata vivarana") of his future Buddhahood by the Buddha Deepankara. At that time he was an ascetic by the name of Sumedha and the Buddha Gotama described the whole event that took place in detail; see, https://en.wikipedia.org/wiki/D%C4%ABpankara_Buddha.
- In the same way, the kamma bÄ«ja stored in the nama loka are instantly activated when proper conditions are realized; see, âAnantara and Samanatara PaccayÄâ. However, unlike nama gotta, kamma seeds fade away with time unless brought to bear fruit under right conditions.
4. Thus, memories (whatever the portion that is remembered) are played back in a âmovie-likeâ manner, like in a dream. It is like a segment of a "movie recording". It is not just a âgistâ or a summary; we can recall the whole âsequence of eventsâ like in a  movie.
- This is why when someone describes an event by memory he/she always tends to tell the story sequentially: The person listening may not want to hear the whole story and could become impatient waiting for the narrator to "get to the point", but for the narrator recalling the event, it is easier to go sequentially as the event is "played back" in his/her mind.
5. We cannot say where that memory is âlocatedâ, because they are not stored in the âphysical spaceâ or the âmaterial worldâ; they are in the ânama lokaâ or âmental worldâ. In contrast what we experience through our five senses is the ârupa lokaâ or the âmaterial worldâ that consists of 31 realms.
- This is also why scientists will not be able to describe the mind in terms of matter; see, "The Double Slit Experiment â Correlation between Mind and Matter?". Mind and matter belong to two distinct domains.
- As I will clarify in detail in the future, this is related to the fact that there are six fundamental entities (six dhatus): patavi (hardness), apo (cohesiveness), tejo (vitality), vayo (motion), akasa (space), and viññÄáča (consciousness). The viññÄáča dhatu is associated with the ânama lokaâ and the other five dhatus are associated with the ârupa lokaâ or the âmaterial worldâ. But we donât need to worry about that right now. You will see other pieces falling into place in a âbig jigsaw puzzleâ as all these seemingly unrelated aspects come together to form a cohesive, complete picture of the âwider worldâ.
- This could be related to the possibility of higher "curled up" dimensions that is being discussed in String Theory in physics; see, âWhat Happens in Other Dimensions?â.
6. We can normally access our own âinformationâ from this life but some people, especially some young children, have the ability to recall nama gotta from past lives. Those who have abhiĂ±Ă±Ä powers can access such âinformationâ or ânama gottaâ of other people as well; however, even they cannot read another's "thoughts" or "kamma bÄ«ja" or "kamma bhava".
- We can retrieve this memory by thinking about it. There is a mechanism for that memory to be retrieved; the mind initiates the process, but the brain acts as the âreceiverâ for the incoming information.
- When we think about something that happened in the past, the mind sends mind rays out and they bounce off that specific target in the  ânama lokaâ and the memory is reflected back. That retrieval process does not change the memory record, and the record stays intact. Thus one can go back and recall it again.
- When the retrieved information comes back, that signal is processed by the brain. Our whole body is prepared by the kamma seed that led to this human existence to limit/facilitate certain capabilities; thus what we can actually remember depends on the status of our brain. Â Our human bodies are generally setup (by kamma vipÄka) to be able to retrieve only the strong memories from the early days of this life and cannot access memories of previous lives. But few people can, and so can some children. Furthermore, if the relevant parts of the brain gets damaged, then the retrieval capability may be lost.
- Some beings in preta loka can remember past lives to impart more suffering on them. They can remember the bad deeds done by them that led to the birth in the preta world, and how long they will have to suffer to âpay back the debtâ.
7. How much of that memory one actually recalls depends on two things: the health of the brain and the purity of the mind.
- If the brain is not functioning well, only bits and pieces of the memory will be actually experienced. When people get old, the brainâs efficiency goes down and thus memory will not work well. The brain is like a playback device and if it is defective, the display will be blurry or at worst no display will result.
8. Secondly, even a person with a healthy brain, may not be able to recall memories if the mind is âcoveredâ by the five hindrances (panca nivarana); see, "Key to Calming the Mind â The Five Hindrances".
- When there is kÄmachanda or vyapada, the mind is too much focused on those objects of thought (arammana). When there is thina middha, the mind is now âstuckâ lazily at something (sleepy or just distracted), and will not retrieve the memory. With uddacca kukkucca, the mind is normally âintoxicatedâ with power, money, beauty etc is stuck at a âlow levelâ. With vicikicca (which is due to micchÄ diáčáčhi or not knowing the true characteristics anicca, dukkha, anatta), one engages in inappropriate acts and thus the mind is not âsharpâ.
- Thus, any, some, or all of these five factors can affect the memory of even a person with a healthy brain. When we purify our minds of the panca nivarana, its ability to pinpoint a given âmemory locationâ is improved.
- Furthermore, when the mind is purified, that can make oneâs brain to function better by changing the conditions for better kamma vipÄka to come to fruition; see, âAnantara and Samanatara PaccayÄâ. This âmind effectâ on the brain and the body in general is being re-discovered by scientists; see, for example, âThe Biology of Beliefâ by Bruce H. Lipton.
9. Â Most scientists and philosophers believe that our memories are stored in our brains. There are key problems with that assumption:
- If that is the case, then the âstate of the mindâ should not be a factor in recalling a memory, because then it is like retrieving a sound track from a disc; the playback should be good as long as the âplaying deviceâ (i.e., the brain) is in good condition.
- Â It is astounding how much one can recall from the memory. And it comes out like a video clip; we can visualize and even recall the conversations that took place a long time ago in case of poignant memories. Can all those details be "stored" in a biological membrane?
- Even if it is possible to encode all that information (exact features of the 10-year old child and her 30-year old mother, what they spoke at that time in the same tone, etc. in the hypothetical example of #1 above), how can it be recalled instantaneously?
10. Here is an article which discusses these unresolved scientific issues:Â http://viewzone.com/memorytest1.html
- Here is a good site if you need to dig in deeper:Â Human Memory Storage.