There are four ways in which memory occurs
- Immediate memory
- Permanent (long-term) memory
- Memory Access
The type of information you’re receiving determines which region of your brain is active. For instance, words are initially processed in the language regions of the brain, pictures initially in the visual regions. This is where your memories are â€œregistered.â€
What do we use our immediate memory for? The almost insignificant use of this immediate memory is when you try to remember a phone number. Most people will notice that they have difficulty repeating more than seven digits of a phone number they have just heard. This is the limitation of your immediate memory.
When information comes into a region, it comes in as a pattern of nerve cell activity. This nerve cell activity normally endures for just a short period of time – seconds or less. This is of way what we deem â€œImmediateâ€ memory
The major reason of immediate memory seems to be that it is part of a scratch pad system that we use in our minds to keep track of what we are hearing and to try to understand it. This can be shown in many ways.
In the extreme, because of damage to the brain, where the damage is so limited that it only seems to affect this type of immediate memory there are people who have very poor immediate memories for words. Such cases are uncommon. Usually, damage in this region of the brain is associated with damage affecting other speech functions.
People with this difficulty typically cannot repeat back more than one or two digits at a time. And they have problems with exact comprehension of what they hear, because they cannot keep track of all the clauses and redirections we normally juggle in our minds.
Permanent (long-term) memory
It will be saved within the same regions of the brain if the information in this temporary pattern of activity is to be permanently stored (and most is not). Saving the patterns of activity consists of changing nerve cell connections so that the pattern of activity can be called forth again, at some later time.
To do this, some nerve cell links are strengthened, while others may be weakened. These changes are comparatively permanent, although the changes may take weeks or months to completely solidify. Even though the solidification occurs in the regions of the brain that contained the original activity, the signal to make the solidification occur came from other regions.
Hippocampus and the thalamus are the best known of these regions with such signaling functions. The hippocampus is on the inner side of the temporal lobe; the thalamus is located deep within the center of the brain.
Remembering what you’ve learned may be a simple matter of just reactivating a latent memory – for instance, by seeing a picture again and recognizing it as recognizable. In this case, the memories get reactivated in the region of the brain where they were first stored.
The measurement of familiarity – the sense of how familiar something is, or how recently you learned it – seems to be done in parts of the temporal lobe, mainly in or near a structure called the amygdala, which sits just in front of the hippocampus.
This simple memory retrieval operates very rapidly. You can decide that a picture is familiar to you or not in less than one-half a second; measuring from the very start of the time you see the picture to the start of when you say “yes” or “no.”
It takes you about two-tenths of a second to actually make the decision, and about another two-tenths of a second to say your answer. once the picture has been registered in your brain (which takes about two-tenths of a second).
The total time it in reality takes you is a little less than the time you spend on each stage, because some of these stages can overlap. You start deciding a picture is recognizable or not while the image of the picture is still developing within your mind.