Differentiate between declarative and procedural memories?

Declarative memories: All information pertaining to facts, names, dates, etc. are port of declarative memory. Example: A rickshaw has three wheels, or India became independent on August 15, 1947, a frog is an amphibian, etc. are parts of declarative memory. Facts retained in declarative memory are amenable to verbal descriptions.

Procedural memory: It refers to memories relating to procedures for accomplishing various tasks and skills. Example: How to ride a bicycle, how to make tea, how to play basketball, etc. The contents of procedural memory cannot be described easily.

Depending upon how much time people take in responding to questions, the nature of organisation in long-term memory, has been inferred.

The most important unit of representation of knowledge in long-term memory is a concept. Concepts are mental categories for objects and events, which are similar to each other in one or in more than one way. Concepts may also get organised in schemas which are mental frameworks which represent our knowledge and assumptions about the world.

In the year 1969, Allann Collins and Ross Quillian suggested that knowledge in long-term memory is organised hierarchically and assumes a network structure. Elements of this structure are called nodes. Nodes are concepts while connections between nodes are labelled relationships, which indicate category membership or concept attributes.

Fig: The Hierarchical Network Model

Maintenance rehearsals: These kinds of rehearsals simply maintain information through repetition and when such repetitions discontinue the information is lost. They are carried through silent or vocal repetition.

Elaborative rehearsals: These rehearsals attempt to connect the ‘to be retained information’ to the already existing information in long-term memory. In elaborative rehearsals one attempts to analyse the information in terms of various associations it arouses. It involves organisation of the incoming information in as many ways as possible.

Encoding: Encoding is registering the incoming information in a way that it becomes compatible to the memory system. It is the first stage of memory.

Storage: It is the second stage of memory. It refers to the process through which information is retained and held over a period of time.

Retrieval: This is the third stage of memory. It refers to bringing the stored information to her/his awareness so that it can be used for performing various cognitive tasks such as problem solving or decision-making.

According to the stage-model, there are three memory systems through which information is processed. These are – sensory memory, the short-term memory and the long term memory.

(i) Sensory memory: The incoming information first enters the sensory memory. Sensory memory has a large capacity. However, it is of very short duration i.e., less than a second. It is a memory system that registers information from each of the senses with reasonable accuracy. Often this system is referred to as sensory memories or sensory registers because informations from all the senses are registered here as exact replica of the stimulus.

(ii) Short-Term Memory: Information that is attended to enters the second memory store called the short-term memory (STM), which holds small amount of information for a brief period of time (usually for 30 seconds or less). As Kinson and Shiffrin propose that information in STM is primarily encoded acoustically i.e., in terms of sound and unless rehearsed continuously, it may get lost from the STM in less than 30 seconds. The STM is fragile but not as fragile as sensory registers where information decays automatically in less than a second.

(iii) Long term Memory: Materials that survive the capacity and duration limitations of the STM finally enter the long-term memory (LTM) which has a vast capacity. It is a permanent storehouse of all informations. It has been shown that once any information enters the long-term memory store it is never forgotten because it gets encoded semantically, i.e., in terms of the meaning that any information carries.