Real important things you cannot find in books, lectures, marketplace or in research papers. 

Truth is not for sale, so there is not promotion, marketing. 

And Truth is so precious, no one is willing to give up or sell it. 

Truth sells itself because of its intrinsic value, as perceived by Truth Seekers. 

But Truth is everywhere, bountiful, you have to just look for it without prejudice with a honest and open mind, in the name of Truth.

"And hold firmly together to the rope of Allah and do not be divided. ...This is how Allah makes His revelations clear to you, so that you may be ˹rightly˺ guided". QURAN Al 'Imran 3:103

And this is not intentional. 

This is "The Way" of things. 

"He gives wisdom to whom He wills, and whoever has been given wisdom has certainly been given much good. And none will remember except those of understanding". Quran, Sura Al-Baqarah 2:269.

In other words, Words of wisdom is hermetically sealed, except those with understanding.

Here is a very important recurrent themes narrated in scripture about not selling what has been "revealed" to you!

1. And do not exchange My signs (revelations) for a small price. Quran, Al-Baqarah 2 : 41

2. Invest in truth and never sell it. Torah, Proverbs 23:23, 

3. Nor trade my revelations for a fleeting gain. Quran, Al-Ma'idah 5:44

4. They do not exchange the verses of Allah for a small price. Quran, AL-IMRAN 3:199

Thinking by heart (Qalb) vs Thinking by the brain. Heart (Qalb) as a seat of certain types of cognitions

Few Terms:

Déjà vu , 

False memory, 

Confabulation, 

Reincarnation memory,

Rememberance and recollection, 

Unconscious memory, 

Repressed memory, 

Muscles or organ memory, 

Memory of the Heart /Qalb, 

Procedural Memory, 

Short term and Long term Memory, 

Synaptic or Cellular Memory, 

Generic Memory

Memory of THE Reality.

Enlightenment or" Divine Rememberance"

Illustrative Example:
From "A Map of the Divine Subtle Faculty: The Concept of Qalb (Heart) in Classical and Contemporary Islamic Scholarship". https://doi.org/10.4226/66/5a962c67c6893
According to the diagram of Qalb (attached), a person's spiritual life or Ruh has the Heart (Qalb) inside (not the brain).
Qalb has 4 more layers inside (different authors arranged them many ways) but here is the simplified arrangement that Qalb contains. 1. Fuad (Inner Heart) 2. Sirr (Secret), 3. Khafi (Archenum) and 4. Akhfa (Super Archenum).

Where is your Memory in the brain?

It is not as simple you might suspect.

Let me start with...

It is NOT stored in one location.

It is NOT stored in a fixed group of Neurons.

It is not stored in synaptic terminals.

It is not stored in a specific neural circuit.

It is not stored by enzymatic modification of certain receptor or proteins or genetic facilitation or silencing via methylations.

Then where is it?

It is the electrical waves between areas (but the same memory can be represented by similar electrical waves but using different neurons each time which is "different" than the original neuron that participated in the memory "encoding" and consolidation phase.

So there is NO fixed locus of memory.

Because there is No fixed location needed, the brain's physical size cannot impose the amount the new memory can be formed. Same brain regions participate creating new and unlimited amount of memory.

It is like, how many times you can create waves in a pond or in a river.

The correct answer is: There are no limits (unlike computer hard disk where every disk has predefined read and write function shelf life at the time of manufacturing the hard disk. So they have a limited size.

Now ask yourself.. Is wave part of the water or wave is what water does!

Is a Movie is part of the TV set or what TV set displays!

And Finally, is memory part of the brain or what brain does! If so.. there does the memory come from?

Think.

Reflect.

Find out.

Footnote #1:
The root of Memory: Brain or Outside Brain? Transmittable?
Memories could be stored in cells outside the brain. Researchers can use electrical shocks to teach common freshwater flatworms (Dugesia dorotocephala) to respond to lighting cues by moving to a particular part of a petri dish. That is, flatworms can be trained to remember a behavior and perform it on cue. Then their head had been cut off, and its brain had grown anew, and the regenerated worms were able to recall the behaviors they had learned to execute under certain lighting conditions. "The tail regenerates," and "showed as good a memory of the original task as did the heads. Memory in flatworms could be transferred through cannibalism, .ie. flatworm could learn the memories (transferred from another flatworm) of another by eating the flesh (non-brain) of another flatworm who had the experience.
Original Articles:
McConnell JV. Memory transfer through cannibalism in planarians. Journal of Neuropsychiatry. 1962;3(1):542–548.
McConnell J.V., Malin D.H. (1973) Recent Experiments in Memory Transfer. In: Zippel H.P. (eds) Memory and Transfer of Information. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-2052-4_15 https://link.springer.com/.../10.1007/978-1-4684-2052-4_15 https://science.sciencemag.org/content/146/3641/274.long
https://psycnet.apa.org/record/1962-00603-001
https://pubmed.ncbi.nlm.nih.gov/23821717/

Footnote #2:
Brain-Heart acts as if they are a pair. Anxiety can initiate tachycardia. Non-anxiety tachycardia (drug-induced tachycardia or Atrial fibrillation) can precipitate anxiety in the brain and vice versa. As I mentioned in the essay, there is a heavy reciprocal Brain-heart Neuronal and "non-neuronal" feedback loop [sympathetic and parasympathetic innervation] and each affects the other.

Footnote #3:
From all the comments, I can gather 3 main issues that have been raised:
1. Question regarding embryology and the heart THE seat of the Soul
2. Effect on Brain from Heart: Transplant data. Confusing and inconclusive data
3. Relevance of Planaria studies to the Human level. They are so different!

We have to remember, the concept Qalb is a symbolic expression using the heart as an organ. The goal of my essay is the show the mental rationale for the ancients why they thought so, which is also approved by many scripture verses. So we have to read between the line and develop our own idea from those "signs", symbols and allegories.
# 1: Question regarding embryology and the heart as The seat of the soul.
My comments:
Ancients thought because the planets, sun, moon are moving, they also have a soul. That sounds ridiculous right. Yes, it does, but that's the way ancients viewed the world.
By analogy, the organ that can move also has "a" (not THE) soul. If you accept the idea of a soul (perceptive and analyzing entity or faculty) our whole body (not only the brain as we know it) has souls in different organs. Skin, Eye, and Muscles, to mention a few, all have their local mechanisms (independent of the brain) to detect (perceive) analyze and respond to the stimuli.
In the essay above, no way I said or claimed that the heart is "THE" seat of the soul. All I am saying from circumstantial evidence from history, Islamic literature, and neuroscience research that the heart might possess a soul-like entity that is developmentally more primitive than the brain in this context. It is obvious, all the mental activity that we commonly perceive and use comes from the brain. Then how can scripture insist that the heart is participatory in one's emotional, intuitive cognition? The purpose of this essay is to show the analogy (NOT a proof or Claim).
But if you take this idea to the extreme and want to say concretely that the heart is the seat of THE soul, then probably you misunderstood the whole purpose and context of this short essay written (in 30 min).
In summary:
1. Many body parts outside the brain have a rudimentary awareness of their environment and the ability to respond to it.
2. Muscle and heart have brain some "memory" of their own, independent of the brain.
3. The heart is NOT the seat of the entire soul of our being but has some soul-like properties (Circumstial evidence from Historical way of thinking, Poetic literature and even Islamic literature, and neuroscience studies)
4. Long before the brain is doing brain function during embryogenesis that can be observed (moving limbs, breathing, seeing, etc), the heart can be seen visibly moving (and by the movement of heart analogy) might lead the ancients and medieval scholars to give special attention to have a possible soul like attributes outside the brain.
5. Heart is relatively centrally located (as opposed to the brain, which is quite terminally located in the body). So the Core of our being is also allegorically expressed by the centrality of the heart in the body.
# 2: Effect of Heart on Brain or Cognition: Transplant data
My comments:
In another footnote, I already explained Brain-Heart acts as if they are a pair. Anxiety can initiate tachycardia. Non-anxiety tachycardia (drug-induced tachycardia or atrial fibrillation) can precipitate anxiety in the brain and vice versa. As I mentioned in the essay, there is a heavy reciprocal Brain-heart Neuronal and "non-neuronal" feedback loop [sympathetic and parasympathetic innervation] and each affects the other.
You are right about transplant data. The transplant studies are also just observation data (not double-blind and not able to control all the possible confounders) that goes in the direction (NO way a PROOF) of the heart's participation in mental state and function. No more and no less.
Actually, we don't need transparent data (inherently problematic because of post-transplant immunotherapy, long waiting period, and the neurotoxic effects of drugs [even after statistical adjustment]. We all can see Brain-Heart act as a pair. When you are calm, your heart rate is also comfortably low. When the heart rate is artificially or chemically increased (independent of the brain's input), we feel anxious and this anxiety can affect our cognitive ability. But is nice to see a paper also suggest the same direction that we are talking about here in the post that's why I included it as again as a piece of circumstantial evidence.
# 3: Relevance of Planaria studies to the Human level. They are so different.
My comments:
Planarian data is just to point out that memory has lots of levels and all these levels are also working in our brain neurons and also in other excitable tissues like skeletal or cardiac muscle.
Example:
1. Cellular memory: Receptor upregulation, downregulation, Kinase activate, cAMP accumulation, and the list goes on.
2. Neuronal Memory: Long Term Potentiation, Synaptic Plasticity
3. Circuit level Memory: Facilitations, Occlusion, Feedforward Inhibition or Stimulation, Feedback loop, etc.
4. Epigenetic Level: Rat experiments where granddaddy rate exposed to electric shock can be transmitted as anxiety respond to next generations without gene alterations.
5. Genetic Memory: All the fixed genetic code designed to perform functions related to memory, is actually selected and preserved for remote ancestors for usefulness (sort of genetic imprinted memory)
So Planarian is an exemplary and illustrative case of the scope of such diverse types of memory.
Because you don't need a brain to remember to do certain things in Planarian, by the same token, you don't need a brain to withdrawal your hand from the fire. The nerve conduction velocity is too slow to go the brain, then come back to the muscle to withdraw your hand. In this case, the mechanism does not go to the brain, and the circuit is more peripheral. If you study, you will see those cellular and molecular mechanisms are still working at the human cellular level too. So it is very analogs to Planaria, and indeed this kind of research is still relevant to humans. See more specifics on neuroscience data below.

Footnotes #5:
Q1:
Has your work here been peer-reviewed?
A1:
Although the post here is as academically rigorous as any others to be accepted and published in many philosophical/theological journals, I am not interested to publish it right now. The "peers" are typically gatekeepers and they typically convolute and complicate the simple meaning (as written here in the post) by various academic jargon so that only "initiated" will get the sense and hence the meaning of the post will not be accessible to any generally educated person.
Q2
If so, I was wondering what sort of questions they asked you.
A2:
The moment you need a peer to support or approve your idea, automatically means, you need some confirmation from others. But the nature of Qalb is such that you don't need peer-reviewed. It is self-evident and self-sufficient. But it is always nice to hear from other people, hence YOU are my peers here and we are doing peer review in an unconventional and unfiltered way.
Q3:
I have a few burning questions on the diagram. Qalb is the heart - is it a biological organ or a metaphysical object or both? Where is nafs located? The splits of the three kinds of nafs and then the whole life form being a complete prediction of life itself - how is that handled? Why is it separated from the other concentric circles?
A3:
Qalb is the core, ancient, archetypal, contemplative subtle inclination and perceptive ability that is associated and symbolized by the physical organ heart. It is not located inside the heart. Just like our mind is not located inside the brain and our mind is associated with the brain.

If you can see what Qalb is, then there is no distinction or boundaries or concentric circles. It is just one thing. The division and boundaries are just tools for description and gradations. There are no such physical boundaries. In simple words, Qalb is just a way of thinking and perceiving reality as they actually are. Once you can see the reality as actually, they are, you will see there is no such rigid boundary.

Original Articles:
https://pubmed.ncbi.nlm.nih.gov/29055147/
https://doi.org/10.4226/66/5a962c67c6893
https://doi.org/10.1007/978-1-4684-2052-4_15 https://link.springer.com/.../10.1007/978-1-4684-2052-4_15 https://science.sciencemag.org/content/146/3641/274.long
https://psycnet.apa.org/record/1962-00603-001
https://pubmed.ncbi.nlm.nih.gov/23821717/
...
https://www.researchgate.net/publication/293944391_Science_of_the_Heart_Volume_2_Exploring_the_Role_of_the_Heart_in_Human_Performance_An_Overview_of_Research_Conducted_by_the_HeartMath_Institute/figures?lo=1