50 years later and Atkinson and Shiffrin’s multi-store model of memory (aka the modal model) is still relevant today. This post summarizes the model in more detail than most introductory Psychology textbooks, which will give you the chance to distinguish your explanations from the rest.
The multi-store model of memory (the MSM) is a product of the cognitive revolution of the 1950s and ’60s. This produced a new wave of experimental research into memory. Before this time, the dominant movement was “behaviorism,” which used the scientific method to study observable actions. Behaviorists believed that since the mind couldn’t be observed it could not be objectively studied. New experimental techniques were developed in the 1950s which allowed psychologists to observe the mind through the use of memory tests. This helped produce a plethora of new experimental findings on memory and it’s from these that Atkinson and Shiffrin’s (1968) MSM was born.
- Limitations of the multi-store model of memory (Atkinson and Shiffrin, 1968)
- Four things you didn’t know about the multi-store model of memory
- WATCH: Multi-store model explained (YouTube)
The MSM tries to explain how memories are formed.The MSM explains memory by focusing on two main points:
- Control processes
Structures (The Stores)
There’s a long-standing debate in cognitive psychology about if our memory is one single thing, or if it’s divided into different parts. The first major claim regarding the MSM, therefore, is that memory is made up of separate structures: sensory stores, the short-term store and the long-term store.
The sensory stores (aka sensory registers):
- There are different sensory stores for different sensory information (e.g. tastes, sounds, sights, smells).
- Information in these stores only lasts a few seconds (or “several hundred milliseconds” to be precise).
- These stores can hold a lot of information but it decays very rapidly. Only a small amount is transferred to the short-term store.
The short-term store (aka working memory)
- This is where we hold information we’re currently paying attention to.
- We can only hold a limited amount of information in our STS. The original “magic number” proposed by Miller (1956) was 7 + or – 2 units. More recent research suggests this number is a bit high and it’s actually about four units information.
- In this store is a rehearsal buffer, which is where we hold information we’re actively rehearsing.
- Information lasts in this store about 15 to 30 seconds. Rehearsed information transfers to the next store, whereas unrehearsed information decays.
The long-term store
- This is where we keep our long-term, permanent memories.
- This has an unlimited capacity and these memories are permanent.
- Memories are stored as a memory trace.
Tip: Detailed descriptions of the MSM should include focus on the characteristics of all three stores, including the duration and capacity. You should also diagram the MSM in exam answers to support your written explanations.
The structures above are constants. But according to the MSM, the flow of information in our memory is actively controlled by the individual using a range of control processes. One metaphor is that of hardware and software. The stores are the hardware and the control processes are the software. The claims regarding these control processes are the major contributions this model has made to cognitive psychology.
- This is how information is transferred from the sensory registers to the short-term store. If we don’t pay attention to something, we won’t remember it.
- This is how information is transferred from the short-term store to the long-term store. The more something is rehearsed, the stronger the memory trace will be in the long-term store. If you only rehearse something a little, you might be able to retrieve it after a few minutes. After a couple of days it might be a faint memory. Whereas if you rehearse something continually, you might be able to remember it for much longer because the memory trace is stronger.
Search and Retrieval
- Searching for information is a control processes in the short-term and long-term stores. We can retrieve information from our long-term memory by using active search processes. Forgetting doesn’t just happen from decay of information it can also be due to search failure (an inability to actively locate the memory trace).
- Information in our STS tends to rely on phonetic coding, like saying something over and over again. Long-term memory relies more on semantic coding, which means trying to make sense of the information by analyzing its meaning and connecting it to what we know already.
Atkinson, R. C., & Shiffrin, R. M. (1968). Human memory: A proposed system and its control processes. In K. W. Spence & J. T. Spence, The psychology of learning and motivation: II. Academic Press. https://doi.org/10.1016/S0079-7421(08)60422-3
Healy, A. F., & McNamara, D. S. (1996). VERBAL LEARNING AND MEMORY: Does the Modal Model Still Work? Annual Review of Psychology, 47(1), 143–172.
Hockley, W. E. (2000). The Modal Model Then and Now. Review of On Human Memory: Evolution, Progress, and Reflections on the 30th Anniversary of the Atkinson–Shiffrin Model, by Chizuko Izawa. Journal of Mathematical Psychology, 44(2), 336–345. doi:10.1006/jmps.2000.1306
Malmberg, K.J., Raaijmakers, J.G.W. & Shiffrin, R.M. 50 years of research sparked by Atkinson and Shiffrin (1968). Mem Cogn 47, 561–574 (2019). https://doi.org/10.3758/s13421-019-00896-7
Travis Dixon is an IB Psychology teacher, author, workshop leader, examiner and IA moderator.