Semantic and Episodic Memory
Semantic memory consists of knowledge about what words mean, about the ways they are related to one another, rules for using them in communication & thinking .In Short this kind of memory makes the use of language possible. Semantic memory is very stable .
Some experiments related to semantic memory have indicated that information is stored in logical hierarchies i.e. from general to specific one. Such organization help us to make logical inferences.
Episodic Memory (Tulving 1972) Consists of long term memories of specific things that happened to us at particular tomes & Places. Thus our “remembrances of past things” make our episodic memory. Unlike semantic memory episodic memories seems to be organized with respect to certain events, which happened in our lives .The episodes don’t have logical organization. Thus episodic memory is less organised, and is more suspectable to loss & less helpful in drawing logical interferences.
Relation between Episodic memory and Semantic memory
Episodic memory may be incorporated into our network of general knowledge & thus become part of our semantic memories.
Encoding & Storing long term memory
Encoding for L.T.M storage, requires special attention or strategies. Just being exposed to something is not sufficient for L.T.M Storage .
Organisation :- Organising or arranging the input in some logical manner helps in long term memory. The organizational encoding may be inherent in the input itself, or it may be supplied by the individual as they learn & remember new things.
When we do our organizational encoding of the input, it is called subjective organization.
Role of Imagery
Images are partial & altered representation of what is in the world around us. Use of imagery while encoding enhances memory.
Role of Constructive process :-During Encoding, the information to be remembered, especially if it is complex event is modified and are not coded as such. Certain details are accentuated while others are simplified, so that encoded information is far from a literal copy of the input. The modification are known as Constructive Process.
BoiHett (1932) in his classic experiment found that with the passing time, subjects simplify the story and only give the gist. Further more they also start drawing inferences.
Constructive Process involve –
- Simplification (Leveling):- Leaving certain parts of the original story. Usually portions that don’t fit our scheme are left out .
- Elaboration (Sharpening) :- Certain parts of the material retained are overemphasized & elaborated more than others .
- Conventionalisation :- What has been retained is produced in conventional form.
Retrieval from LTM
Retrieval cues or reminder direct the memory search to the appropriate part of long term library and therefore it is important to have retrieval cues or tags encoded along with information as it is put into LTM.
Retrieval is quite good when condition favor rich & elaborate coding. When we learn thing, we often provide our own retrieval cues at the time we encode information for storage just as we often provide our own organization i.e subjective organization of what we are learning. However retrieval cues are by themselves present in the information encoded.
State Dependent Memory –State dependent memory is rather compelling demonstration of situational influences that affect retrieval from L.T.M .Hoetal (1975) found that animal encoded information when they are in a particular emotional or drugged state ,they may not be able to retrieve information when they are in another emotional state or are no longer drugged .
The emotional or drugged state is a part of the context within which memory is encoded or stored.Without the context retrieval is poor with it retrieval is good.
Reconstructive process in retrieval
A constructive process refers to modification in the information input at encoding stage, whereas reconstructive process are modification of already stored input (retrieval stage). The distinction between constructive & reconstructive process is often blurred. It may be difficult to tell whether the modification in memory occurred at encoding stage or later. Reconstructive process is sometimes called confabulation in the case of people with memory disorder, who have stored very little & who then try to fill the memory gaps during retrieval.