Long term memory

Remember the chapter on Attention and Consciousness? We learned in it that we must "pay attention" when we process information and want to store it for later when we try to remember it. When someone asks you to remember a certain concept, give a list of book titles you read lately, or do a task that require a conscious effort, you most likely use explicit memory which requires conscious recollection of previously stored information in your Long-Term Memory (LTM). But there are times when we do not need consciousness to remember some information stored in the Long-Term Memory (LTM) and then we use implicit memory - recall of information that does not require conscious recollection. Implicit memory can be developed through repetition till the information becomes automatic, such as different motor skills, procedures, or when you learn rules of a game but once you mastered the game you don't have to think anymore to the rules. Or for example if you are given a list of words to read, later you will notice that some words (that you encountered recently) are remembered easier.

When we use explicit memory we use a conscious effort to remember something, so that we can declare what we remember. But implicit memory does not require effort and many times is related to procedural memory (when it becomes automatic).
When you first learned how to ride a bike, you had to pay attention to what you were explained and what you were doing. You had to learn step-by-step (and fall by fall :-) ) how to do that procedure. But once you practiced enough you mastered the procedure till it became automatic (automaticity), and now you don't even think about what you really do, and how do you keep your equillibrium on that bike. That means, through automaticity your explicit memory of that procedure transformed into implicit memory, procedural memory, that does not require conscious effort to perform.

If explicit memory can be lost such as in amnesia, implicit memory is more stable. That is why some people who suffer of amnesia still know how to walk and ride a bike and dial their phone number even if they don't remember it.





Let's take a trip in the warehouse of memory. Long Term Memory (LTM) is our memory warehouse. Our brain stores in an efficient way our knowledge about the world. We learned first that when we perceive the information, following the laws of perceptual processing (remember Gestalt), we do bottom-up and top-down processing. That means, in the process of storing new knowledge we use our previously stored knowledge, and perceptions about the world, and in this process we take into consideration the context. Our knowledge stored in LTM can be about facts (Declarative memory), and skills, or procedures (Procedural memory). The LTM about facts is stored in networks called schemas. We have a schema about what a table means, what means going to school, and what means Milky Way :-)

Our declarative memory holds the meaning of concepts, knowledge, information about our world ( the meaning of abstract knowledge as well), and that is called Semantic memory. Also under the declarative memory we have the memory of our life history, and schemas of different actions we take, list of structured events such as what we do when dinning out to a resturant, what we do at the stop light when we would like to cross a busy street. These structured/serial lists of events in a particular and repetitive order are stored in the Episodic memory.

In order to store the information from WM into LTM we use the process of encoding the information. When we encode we relate the new information to pre-existing information in the LTM. We use attention and consciousness and in the process of encoding we link the new information to older information already stored. When we give a meaning to the information we process that information at a deep level (we use attention and consciousness).

The deep level of processing comes from the fact that we make distinct the new information from old ones -- distinctiveness means how different is one information from other. You teachers might have heard in other courses many times the advice to "make it meaningful" when you teach a new content. That is coming from the need to process the information at deep level so it is better encoded and stored in the LTM.

You remember Allan Baddeley's theory of WM and the special feature of Episodic Buffer. We know that is the working memory part which will help us relate the new information with personal information (episodic memory from LTM). In the process of encoding if the new information is related to previous personal information this will also create a deep level of processing -- self-reference effect. As teacher you might have been instructed to make things hands-on and personal. The reason behind that advice comes from the necessity of deep level of processing of information, and linking the episodic buffer from WM with the episodic memory from LTM. In this process our frontal lobe, specifically the prefrontal cortex presents activity in the process of encoding of self-specific information.

A good advice is that when you meet a person for the first time don't only shake hands, but since you know about deep level of processing and the need to encode meaningful and personal information, next time when you shake hands repeat the name of that person (phonological loop + semantic memory), pay attention to the face specifics and any differences from another person with the same name (perceptual processing, distinctiveness, self-reference, episodic memory), and try to keep longer eye contact looking at the different features of the face so you can encode more information.

Remember (sic!) encoding and retrieval of information are related, that is in other words: what you put in that you will take out. Noise in, then noise out!

More than that it matters the encoding and retrieval context. We process information in a context, our encoding is context dependent. We are not computers to process only the stimuli that are input we process the context, and we are dependent on our physical, psychological, and emotional well being. You know that your students do better on tests if they take the test in their own classroom than in another classroom or other environment. Guess what.... there is plenty of research on encoding specificity that demonstrates the importance of the context.
If we are hungry, happy, or angry and all other emotions, moods, and physical and physiological conditions of our being will affect the way we process, encode, and store the new information.
Storage, encoding will also affect our information retrieval.

When we talk about retrieval we must make the difference between: recall and recognition. Recall supposes an effort in retrieval of the information (as when you are asked to remember all the Presidents of the United States); as opposed to recognition (when some part of the information is already present -- first three letters of each name; which is also a used method to test implicit memory). In teaching/learning is the difference between taking essay exams (recall) as opposed to multiple choice ones (recall + recognition).

This is very important for educators since teachers should take steps to activate existing schemas before presenting new information. That is why you will hear often the advice that you must make the information presented to your students meaningful, personal, and give hands-on experience (that will help to make the information personal). Also remember that when we process new information we link it to previous one stored in our LTM. New is linked to old, and when we retrieve some newer information will activate and bring with it old one (Parallel Distributed Processing). One more reason to stop and ponder our stereotypes!

One big question is: do we keep all of it or do we loose some in order to store more, newer information?

As with many other things, with memory is the same saying "use it or loose it."
We might not loose the information, all that we ever learned might be still available, but it not all accessible because of interference and/or decay. In the process of encoding, by rehearsal in the WM, the information is stored in the LTM, but since we do both bottom-up and top-down processing, we modify the stored information, linking it to older knowledge, reformulating, constructing, and developing constantly our knowledge and meaning in the LTM. Then when the information is retrieved it might be modified. That is why flashbulb memory is not like a DVD in our brain. We can add, modify, blur, or even delete some of the information that we think only it is a perfect video of a certain event.

Easy useful site here.