Atkinson–Shiffrin Model

From the plethora of memory models in the 1960s and 1970s, the Atkinson-Shiffrin model (Atkinson & Shiffrin, 1968) emerged as the most accepted and enduring.

In propounding the model, Atkinson and Shiffrin divide memory into three major types of storage:

1. several peripheral sensory stores or buffers that each accepts information from one sense modality;
2. a short-term store that is fed by the sensory buffer stores; and
3. a long-term store that exchanges incoming and outgoing information with the short-term store (Hulme & Mackenzie, 1992).

Some sort of filtering device is assumed to allow only a certain amount of the unlimited information in the passive sensory store (held there for only a very brief interval) to pass to the short-term, limited store.

After another brief interval, information proceeds from temporary short-term storage to more durable long-term memory.

Atkinson and Shiffrin view short-term memory Opens in new window as the workspace for long-term learning. They were also the first to introduce the notion of contro process in memory Opens in new window, suggesting that these control processes flexibly divide limited capacity storage and processing functions.

The first component in the Atkinson-Shiffrin information processing memory model is sensory memory or storage, also known as immediate memory or the sensory register Opens in new window. This form of memory is closely associated with visual and auditory perceptual processing.

The brief retention of visual information is referred to as iconic memory Opens in new window, whereas brief auditory retention is referred to as echoic memory Opens in new window (Torgesen, 1996).

Both types of storage last only for a matter of milliseconds, just long enough to create a trace or activate some form of representational code from long-term memory Opens in new window for further processing in short-term memory Opens in new window.

Short-term memory Opens in new window is the central feature of the model. As described by Atkinson and Shiffrin (1968), short-term memory has very limited capacity. Information in short-term memory quickly fades unless it is maintained through rehearsal (subvocal repetition).

Forgetting Opens in new window also occurs as new units of information displace old units. The encoding Opens in new window or transferring of information into long-term storage depends on short-term memory.

Atkinson and Shiffrin propose that learning is dependent on the amount of time information resides in temporary storage. This model also assumes that short-term memory plays an important role in long-term retrieval.

Despite the division of memory functions, Atkinson and Shiffrin believe that long-term memory and other cognitive processes are also involved in performance of immediate serial recall tasks (Hulme & Mackenzie, 1992).

As research continued, the Atkinson-Shiffrin model, which was referred to as the modal model, was found to be an oversimplification of memory and to place too much emphasis on structure while ignoring the processes.

For example, little support has been found for the prediction that the probability of learning a piece of information is a function of how long that information resides in short-term storage.

Experiments in which subjects use rote rehearsal to maintain items in short-term storage have failed to find this predicted relationship (Baddeley, 1996a).

With the emergence of working memory theories, the modal model faded away. Nevertheless, Atkinson-Shiffrin’s three-part division still provides a useful framework for interpreting memory performance, and it is consistent with the information processing model that persists to this day.