In late 1960s, many researchers in the field of memory believed that human memory model is based on the connectionist approach. Martindale (1991) viewed that the information processing explanation of memory is a well- researched framework for examining human learning and memory.
Information processing view of memory uses computer as a model for understanding memory systems, though human memory and computer memory are definitely not identical (Lewandoswky, & Murdock, 1989). Like the computer, the human mind takes in information, performs operation on it to change its form, stores the information, retrieves it when needed, and generates responses.
The three basic tasks that are performed in this process are encoding, storage, and retrieval.
Several important models of memory, which rest firmly on this (Information Processing) approach, have been proposed. Of these, the model proposed by Atkinson and Shiffrin (1968) is the most influential one.
According to this model, there are three kinds of memory systems: (i) sensory memory (sensory register), (ii) short-term memory, and (iii) long-term memory. These storehouses vary in terms of their functions and the length of time they retain information.
In the Atkinson-Shiffrin model (see Figure 6.2), memory starts with a sensory input from the environment. This is held for a brief period of time (a fraction of a second). Information that is attended to and recognized in the sensory register may be passed on to short-term memory (STM), where it is held for 15 to 25 seconds.
Some of the information reaching short-term memory is processed by being rehearsed again and again, and then passed on to the long-term memory, and information not so processed is lost.
When items of information are placed in long-term memory, they are organized into categories, where they may reside for days, months, and years or for a lifetime. When you remember something, you first search for it in the STM; if it is not found there, you begin searching in the LTM.
The mental representation of the item is retrieved from the LTM, and transformed to the STM, where you can then consciously deal with it. A diagrammatic representation Of such a model is given in Figure 6.2. The three memory systems are discussed separately below.