There is a common knowledge that several brain areas are involved in memory processes and each area is involved in a different aspect of memory.
But where do our memories get stored and how are they retrieved again?
This is a good question.
The question of "where" is not answered yet by mainstream science. One problem is the huge amount of data we get only through our eyes each day, approximately about one terrabyte if this data is compressed by modern algorithms. A lifetime of 100 years would be almost impossible to store "inside our brain".
There are some alternative theories which could explain how the brain stores data. Maybe our brain works like a antenna, similar to a computer which has a access to a vast data pool from the internet. You could ask the question where is the movie inside the television or where is the internet inside the computer? Certainly a computer has a harddrive, a local data storage unit and a cpu, but it is very limited in processing everyday data for a lifetime. It would be very restricted if it would not access to outer data pools.
Carl Gustav Jung has wrote about the theory of a collective subconsciousness and he was in contact with Wolfgang Pauli, a quantum physics pioneer. I would not wonder if we one day discover that our memory is nonlocal.
To explain this, it depends how far we want to go with the answers.
There are many unknowns in that field, because it's paradox of using our brains to understand our brains. Basically our brains are too complex and if we were simpler, we'd be dumber and couldn't understand it, anyway.
As Ian Stewart quotes:
'If our brains were simple enough for us to understand them, we'd be so simple that we couldn't.'
Here are some answers according to mainstream science:
All our memories do get stored by the brain for varying periods of time; some are stored in our short term memory and don't stick with us for very long, while others are filed away in our long term memory. The actual capacity of our brains for storing memories has been difficult for scientists to determine, though it is believed that because our brains consist of a vast number of neurons
Experts believe the brain uses three memory-storing stages: sensory, short-term and long-term. The different stages act as filters, beginning with when we first see something, until the flood of information is processed. The filtering protects us from having too much unnecessary information requiring storage. Perception, therefore, is the first step in memory creation and is associated with the sensory stage, where the registration of information during perception takes place for a brief second. Sensory and short-term memory information tends to decay rapidly, with only the important information gradually moved to long-term memory.
Short-term memories like a possible chess move, or a hotel room number are processed in the front of the brain in a highly developed area called the pre-frontal lobe, according to McGill University and the Canadian Institute of Neurosciences, Mental Health and Addiction.
Science tells us that while our brain may store different types of memories in various areas of the brain, recalling a memory is a brain-wide process.
Types of memories and where they are stored in the brain include:
- Semantic memory: General knowledge, trivia and facts are stored in the temporal lobe and the cortex.
- Episodic memory: New data and recent events are stored in the prefrontal cortex and the temporal lobe.
- Working memory: Information and knowledge required for daily life -- such as telephone numbers and learned skills like driving --
are stored in the prefrontal cortex.
- Procedural memory: Secondhand skills, things we take for granted, such as walking and cycling, are stored in the cerebellum.
While it isn't known exactly how many connections are possible in the brain, or how large the storage area for memory might be, scientist do know that our memories are not stored in one memory center in the brain, rather, the events and experiences of a single memory may be stored in many different areas of the brain. For example, when someone recalls a trip to the beach, he or she might remember that the sand was white, the ocean was blue, the air smelled like salt water and seagulls were squawking. To recall that one memory, the brain doesn't visit the "beach memory center," but pulls the different components together from various cortices. The blue water and white sand are retrieved from the visual cortex, the salt water smell from the olfactory cortex, and the squawking gulls from the auditory cortex.
For the average person, not every memory is consolidated, or stored, in long term memory, freeing up space. But in certain rare cases of exceptional memories, some people have been known to store and perfectly recall nearly every detail of every memory from most of their lives, a syndrome known as hyperthymestic syndrome. Researchers declared the first known case of hyperthymesia in a subject known as AJ, a then 40-year-old woman could accurately recall every event that had ever happened to her since the time she was 14 years old.
Another thing what is also interesting to point, that Einstein's brain was removed during an autopsy and kept it in hopes of studying it to unlock the secret of Einstein's genius. It's theorized that the lack of the fissure allowed his brain cells to communicate faster than the average human's. In summary the three histological studies of Einstein’s brain have, in spite of claims to the contrary, found essentially no differences between his brain and that of controls. This should not come as any great surprise. The brain is obviously an extremely complex structure… to believe that the analyses of one or a few tiny slices of a single brain could reveal anything related to the specific cognitive abilities of that brain is naive.
According to New Age movement and similar (not supported by the mainstream science) our brain is a biological computer that interfaces with a conscious entity (our consciousness, soul or higher-self). And our experiences/memories are stored in forms of the akashic records (on quantum level in forms of photons) in our DNA (which is our quantum mechanical biowave computer) as part of our etheric body and are retrieved by our consciousness by our free will. Various of peoples out-of-body experiences supports that theory including some scientific evidences. Our brains still have some storage function, but it's not the main repository of our memories/experiences.
The scientific theories are in favor for above:
There is also the new research from Emory University School of Medicine, in Atlanta, has shown that it is possible for some information to be inherited biologically through chemical changes that occur in DNA.
“I regard consciousness as fundamental. I regard matter as derivative from consciousness. We cannot get behind consciousness. Everything that we talk about, everything that we regard as existing, postulates consciousness.” – Max Planck, Nobel Prize winning originator of quantum theory, as quoted in The Observer (25 January 1931)
Max Planck said "As a man who has devoted his whole life to the most clear headed science, to the study of matter, I can tell you as a result of my research about atoms this much: There is no matter as such. All matter originates and exists only by virtue of a force which brings the particle of an atom to vibration and holds this most minute solar system of the atom together. We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter" in 1944.
Albert Einstein: "A human being is a part of the whole, called by us "Universe," a part limited in time and space. He experiences himself, his thoughts and feelings as something separate from the rest—a kind of optical delusion of his consciousness. The striving to free oneself from this delusion is the one issue of true religion. Not to nourish it but to try to overcome it is the way to reach the attainable measure of peace of mind."