Lara Wainwright AS Psychology Outline and evaluate the multi-store model of memory (12 marks) There are three parts of the multi-store model of memory; sensory memory, short-term store and long-term store. The model was proposed by Atkinson and Shiffrin in 1968. The proposed that information enters the system from the environment and first registers on the sensory memory store where it stays for a brief period of time before either decaying or passing onto the short term memory store.
Sperling (1960) did a sensory store experiment, which involved showing the participants three rows of letters (12 on the chart) for a split second which they then had to recall. The findings showed that only a fraction of the letters were passed on to the short-term memory. This experiment had no ethical issues, was it a lab experiment so it had high levels of control and it was also reliable and based on evidence. Although it did lack validity as it was artificial and is not how we use everyday memory.
The short-term memory store has a very small capacity (Miller’s Magic 7), where information can be lost within seconds if they are not rehearsed. If the material is sufficiently rehearsed, it passes on to the long-term memory, if not, that information is lost. Long-term memory refers to relatively permanent storage, which has unlimited capacity and uses a semantic code. Psychologists Glanzer and Cunitz (1966) tried to show the existence of separate long-term memory and short-term memory, and their results were able to show this.
This experiment was in a highly controlled laboratory experiment that has been successfully repeated many times. As well as this, evidence from other studies provides further support for separate short-term memory and long-term memory stores. Also, studies of brain damaged patients supports separate short-term memory and long-term memory because with most patients only one part of the memory was affected. There were also many limitations to this experiment such as the age of the participant because the older the participant is, the more likely their memory isn’t going to be as good as others.
The rate of presentation could also affect it, because the slower the words are read out the better the performance, whereas if it was read out quickly to someone else they would have a poorer performance. As well as this, some psychologists may question that the memory could be more complex than simply a sensory store, a short-term memory store and a long-term memory store. At each stage of the process of the memory store there are constraints in terms of capacity, duration and encoding.
Capacity in long-term memory is potentially unlimited, but it is possible to lose things from long-term memory through processes such as decay and interference, but loss does not completely occur because of capacity limitations. However, the capacity for short-term memory is different. Short-term memory has a very small capacity, estimated by Miller (1956) in his magic seven theory that the span of immediate memory is about 7+/- 2. This supports the view that short-term memory is very limited and that its limit is between 5 and 9 items.
However, an ‘item’ may consist of small chunks. The ability to chunk data is a way to increase the capacity of short-term memory. There has been lots of research evidence that supports Miller’s theory, especially when information is chunked. Cowan (2000) believes Miller might’ve overestimated the number of chunks that can be held in short-term memory. He thinks that performance on span tasks if often affected by rehearsal and long-term memory, and doesn’t reflect the capacity of ‘pure’ short-term memory. Individual differences can also affect short-term memory capacity, e. . people who are highly anxious appear to have shorter spans. Duration refers to how long a memory is stored. Short-term memory is a temporary store and anything we need to retain for longer periods has to be transferred to long-term memory. Peterson and Peterson (1959) tried to find out how long items remain in short-term memory without rehearsal. Participants were presented a triagram consisting of 3 consonants, which they would have to recall in order after a delay of 3, 6, 9, 12, 15 and 18 seconds, but in-between they were given an interference task.
This experiment gives us more knowledge about short-term memory because there results showed that very little information remained in the short-term memory for more than 18 seconds or so. The experiment was carried out in controlled conditions and there were no ethical issues to affect this experiment. However there were a few limitations, such as the use of triagrams are very artificial and not part of everyday use of memory, also, loss of information was more to do with capacity limitations rather than duration.
Proactive interference, such as earlier triagrams being used could’ve caused confusion, as well as this people may have been rehearsing the triagrams which would store them in the long-term memory instead. Once information is stored in the long-term memory it is possible to potentially remember that piece of information forever, although, Bahrick et al did an experiment on 392 graduates of an American high school to recall their class mate’s details after leaving school. He came to a conclusion that long-term memory starts to decay after a period of 47 years.
Many people questioned this experiment, asking whether this was due to the aging of the participants or was it actually showing duration of long-term memory. Depth of learning is another issue as there memory now depends on whether they learnt that information well enough in the first place. Encoding may be based on the sound of the information (an acoustic code), the way the information appears visually (a visual code) or may be in terms of a meaning (a semantic code). Short-term memory tends to be stored acoustically whereas long-term memory is more semantic.
Baddeley (1966) investigated encoding in short-term memory and long-term memory. He gave participants four sets of words, either acoustically similar, acoustically dissimilar, semantically similar and semantically dissimilar. It was concluded that the patterns of confusion between similar words suggest that long-term memory is more likely to rely on semantic encoding and short-term memory on acoustic encoding. His experiment was questioned on whether there are other types of long-term memory (e. g. pisodic and procedural memory) which this experiment didn’t consider. As a whole, the multi-store model of memory has made an important contribution to research on memory. The information processing approach has enabled psychologists to construct testable models of memory and has provided the foundation for later work into memory. It is also a simplistic way to describe how memory works; also most psychologists would agree that there are distinctions between short-term memory and long-term memory. Besides from the strengths, there are limitations to this model too.
There are a couple of methodological problems, which includes that much of the supporting evidence comes from artificial, laboratory studies, which might not reflect how memory works in everyday life. Also, it is possible to interpret results in different ways, like experimental techniques can yield different results. The multi-store model being simplistic can also be a weakness as memory research data have accumulated that traditional multi-store models simply cannot explain memory process more fully. It is possible to argue that memory may be more interactive than just a one way system.