The Atkinson-Shiffrin model is a psychological model proposed in 1968 by Richard Atkinson and Richard Shiffrin as a proposal for the structure of memory. It proposed that human memory involves a sequence of three stages: sensory memory, working or short term memory, and long term memory.

Environmental stimulation is initially received by the sensory store. These stores are modality specific (e.g. vision, hearing). Information is held very briefly in the sensory stores with some being attended to and processed further by the short term store. Some information processed in the short term store is transferred to the long term store. Long term storage of information depends on rehearsal.

Sensory memory

The incoming information first enter the sensory memory where the information is registered. This level retains the unprocessed signal images of the physical energy received from sensory channel. Though the system has a large capacity but it is of very short duration, i.e. less than a second. This system registers information from each of the senses with reasonable accuracy. Often the system is referred to as a sensory register because information from all senses are registered here as exact replica of the stimulus.

Sensory memory can be of different types - the visual sensory memory is referred to as iconic memory and the auditory sensory memory is referred to as echoic memory.

Short term memory

This is the second level store of memory. It is limited in capacity and storage time. It is an active system of memory because it constantly handles, combines, and transform the materials drawn from the long term memory as well as the sensor memory. Since information in short term memory last for a brief period only it is usually known as immediate memory chamber. Miller, 1956 conducted a digits span experiment and asked participants to listen to a random series of digits and then repeat them back immediately in the correct order. The maximum number of digits recalled without error is usually “7 plus or minus 2" (Miller, 1956).

Maintenance rehearsal

Experimental studies suggest that the materials in the short term memory without rehearsal does not last for more than 18 seconds, such rehearsal trials are also called maintenance trials because rehearsing helps in maintaining the materials in the short term memory for some longer duration.

Primacy effect

The idea that the first things on a list are more likely to be remember than the middle items.

Recency effect

The idea that the last items on a list are easily remembered.

Serial position effect

A theory that serves as an umbrella theory for both of this effects.

Long term memory

Materials that survive the capacity and duration limitations of short term memory finally gets entry into the long term memory. Waught and Norman (1965) hold the view that transfer from short term memory to long term memory is a random process. So through rehearsal and repetition longer an item is in short term memory the greater is the probability of the item for getting into the long term memory. Rehearsing perhaps increases the likelihood of organizing the information and relating it to prior existing other information in the long term memory.

In this model, as with most models of memory long term memory is assumed to be nearly limitless in its duration and capacity. It has in its store various kinds of experiences, learnt abilities, memories of historical events, social interactional experiences, various kinds of scientific laws, principles, rules, various kinds of concepts etc. The storage capacity is practically infinite.

Strengths of the model

The multi store approach has various strengths

• The conceptual distinction between three kinds of memory store (sensory store, short term memory, and long term memory) makes sense. These memory store differ in several ways like temporal duration, storage capacity, forgetting mechanisms and effects of brain damage.
• The multi store model was a pioneering model of memory that inspired for the research and consequently other influential models, such as the working memory model.

Limitations

• The model is arguably over simplified.
• In 1974, Baddeley and Hitch came up with a working memory models proposing that short term memory is subdivided into multiple components which was not addressed in the original Atkinson-Shiffrin model.
• This model considered rehearsal as the sole transfer mechanism. However Craik and Tulving’s work in the 1970s suggest that memories encoded in a more semantic process are more likely to make their way into long term memory.
• Endel Tulving (1972) went further to categorised different types of long term memory. Episodic, procedural and semantic memories are all stored differently. Various cases of memory loss in which people can remember how to brush their teeth but not their father’s birthday show how possible it is that these memories are stored in different places. This was not addressed by the model.

Reference

• Cognitive Psychology: A Student’s Handbook 6th ed. Michael W. Eysenck and Mark T. Keane

Author: Sayani Banerjee

Hey there, curious minds! I'm Sayani Banerjee, and I'm thrilled to be your companion on the fascinating journey through the realm of psychology. As a dedicated student pursuing my master's in Clinical Psychology at Calcutta University, I'm constantly driven by the desire to unravel the mysteries of the human mind and share my insights with you. My passion for teaching and my love for research come together on my blog, psychologymadeeasy.in, where we explore the world of psychology in the simplest and most engaging way possible.