The Multi-Store Model of Memory

What are the feautrues of Atkinson & Shiffrin's (multi-store) model of memory

1) Information flows through a number of storage systems 2) There are three main storage systems 3) Each stage differs in terms of: i) Coding - the form in which the information is stored ii) Capacity - how much information can be stored iii) Duration - how long information can be stored for 4) Information can remain in short-term memory by maintenance rehearsal, and such repetition will create a long term memory 5) The more information is rehearsed, the better it is remembered 6) Information can be lost from each store, but in

Define coding

As information enters the brain via the senses, it is transformed into a code so that it can be stored. The codes can be visual (pictures), acoustic (sounds) or semantic (the meaning of the information).

Describe research into coding in the LTM

Baddeley was interested in how information was coded in both STM (i) and LTM (ii). Participants were divided into groups (independent groups design) and given different lists of words to learn: Acoustically similar words (they sound the similar) e.g. man, mad, map Acoustically dissimilar words e.g. pen, day few Semantically similar words (they mean similar things) e.g. great, big, large Semantically dissimilar words e.g. hot, old, late In the long term memory condition they had to recall the words in the correct order 20 minutes after hearing them. Results: In LTM, recall of semantically similar lists were recalled the worst, with a correct recall of 55%. With the other lists, accurate recalled was much better, between 70% - 85%, with acoustically dissimilar words recalled the best. Conclusion: as semantically dissimilar words were recalled more accurately than semantically similar words, there must be some semantic confusion in LTM during recall, which suggests that coding is semantic. As there was little difference in recall for the acoustically similar and dissimilar words, this would suggest that the sound of the words is not the coding used in LTM

Evaluate the supporting evidence for coding in the sensory register

Because of the nature of the topic, there is very little scientific evidence into the coding of information in sensory memory.

Describe the duration of the sensory register

Between the sensory register and short-term memory there is a filter called 'attention'. It is believed that information that is not attended to is lost very quickly According to research, iconic memory has a very short frequency, maybe up to ½ a second (500 milliseconds). It is a little longer in echoic memory, with information remaining for about 3 seconds. Iconic memory is thought to cause the impression of an illuminated line when you wave a sparkler on bonfire night, you can even spell out someone's name.

Describe the duration of the STM

How long information can stay in short-term memory ranges from a few seconds up to a minute, but for most of us, it is somewhere in between: textbooks often refer to between 15 - 30 seconds, (but this can be extended due to rehearsal).

Describe the capacity of the STM

How much information can be held in STM is limited. Notwithstanding that there are differences in capacity depending on the type of information, it is universally agreed that people can hold about seve +/- items in STM

Describe the coding in the STM

In short term memory (STM) it is widely accepted that the coding is mainly acoustic. When a person is presented with a list of numbers and letters, they will try to hold them in STM by rehearsing them (verbally). Rehearsal is a verbal process regardless of whether the list of items is presented acoustically (someone reads them out), or visually (on a sheet of paper). However, it is also recognised that visual coding does occur in STM, as does some semantic coding.

Describe coding in the LTM

It is widely acknowledged that information is coded semantically in LTM, especially for verbal information. This means that information is stored in LTM when it has meaning or in other words, some relevance or importance to us. However, there is some evidence for both visual and acoustic encoding in LTM.

Describe the research into the capacity of the STM

Jacobs (1887) conducted the first systematic study on the capacity of memory. Procedure:Participants were presented with a sequence of digits or letters and required to repeat them back in the same order (for example, 6,3,8,9,4,7,2 or G,S,T,J,W,V,K,L). The pace was controlled at half second intervals using a metronome. The procedure was repeated a number of times and the longest list of sequences that was correct 50% of the time was taken as the participants digital span. Jacobs found that participants recalled more digits than letters. The average span for digits was 9.3, whereas it was 7.3 for letters. Jacobs also found that capacity increased steadily with age; in one sample of school girls he found that 8 year olds remembered an average of 6.6 digits whereas for 19 year olds it was 8.6 digits. The capacity is usually phrased as 7 + or - 2, so the capacity of STM is known as 7+ or - 2 items (also see research by Miller.)

Describe the supporting evidence for coding in the sensory register

Sensory Register - Coding - Crowder 1993 Supporting evidence: Crowder (1993) suggests that the different duration in SR between echoic and iconic registers suggests that information is coded according its sense modality. For example Iconic register: memory for visual information (1/2 a second) Echoic register: memory for auditory information (2 seconds) This demonstrates that the information is coded depending on the sense modality which registers it, and it is suggested that it is pre-perceptual, that is that very little processing, if any, is conducted on the information

Describe sensory register

Sensory register, also called sensory memory, refers to the first and most immediate form of memory you have. The sensory register is your ultra-short-term memory that takes in sensory information through your five senses (sight, hearing, smell, taste and touch) and holds it for no more than a few seconds. Our senses are engaged when we are exposed to a stimulus or something that causes a sensory response, such as a strong odour. It is the sensory register that enables you to remember sensory stimuli after your exposure to the stimuli has ended.

Evaluate the research into the duration of the STM

The artificial nature of the task means that there is low ecological validity, as information is rarely in such basic form. So it is difficult to conclude this study tells us anything other than how people recall trigrams under strict laboratory conditions. For example March et al (1997) showed that if people were not expecting to have to recall information, STM had a maximum duration of four seconds. It also fails to explain STM for other types of information, such as visual or haptic memory

Evaluate research into the capacity of the LTM

The capacity for LTM is impossible to study with any scientific rigour, and until we develop advanced technology, the precise capacity for LTM is likely to remain unknown.

Describe the capacity of the LTM

The capacity in LTM is generally accepted to be unlimited. Therefore, no matter how much information is stored long-term, the store never becomes full.

Describe the capactiy of the sensory register

The capacity of the SR is very large, with the information contained being in an unprocessed, highly detailed and ever-changing format.

Define sensory register

The first store which holds the sensory information received through all the senses for a brief period of time. Examples include iconic (visual) and echoic (sound) memory.

Evaluate the supporting evidene for the duration of the sensory register

The highly artificial setting of the laboratory means that it is difficult to accurately predict similar findings in real life situations, where the environment would be noisier or with more fleeting images, so mundane realism is an issue with such studies.

Evaluate research into coding in the LTM

The laboratory study means there is a high likelihood of replicability, and internal validity, where cause and effect can be argued. However, the artificial nature of the environment and tasks means that ecological validity should be questioned, as it is unclear if this coding occurs in other situations. Therefore, conclusions about the coding of LTM largely being semantic should be made with caution.

Evaluate the research into coding in the STM

The laboratory study means there is a high likelihood of replicability, and internal validity, where cause and effect can be argued. However, the artificial nature of the environment and tasks means that ecological validity should be questioned, as it is unclear if this coding occurs in other situations. Therefore, conclusions about the coding of STM mainly being acoustic should be made with caution.

Define duration

The measure of how long memory lasts before it is no longer available

Define capacity

The measure of how much can be held in memory. For example, how many digits can be held in STM

Define short-term memory:

The memory for immediate events. These memories tend not to last for more than a minute or two, usually shorter, and disappear unless they are rehearsed. Capacity is limited to 7 plus or minus 2 individual items.

Define long-term memory:

The memory for past events that can last for the life-time of a person. Its capacity is most probably unlimited

Describe research into the duration of the LTM

Their aim was to investigate the duration of long term memory to see if memories can last over decades, and thus support the idea that the duration of memory can be a lifetime. A sample of 392 American ex-high school students aged from 17-74 was studied. They were asked to remember the names of their classmates (free recall) and they were then shown faces and names of classmates and asked if they recognised them. The accuracy of participants recall could be assessed by using their high-school year-books, which contained both pictures and names. There was 90% accuracy in face and name recognition, even with those participants who had left high-school 34 years previously. After 48 years this was 80% for name recognition and 40% for face recognition. Free recall was less accurate: 60% after 15 years and 30% after 48 years. Bahrick et al concluded that peoples' long tem memories can last for their whole life, even though they may weaken over time. Recognition is better than recall

Evaluate the MSM (supporting evidence - brain localisation)

(P) In biological evidence into brain localisation using MRI scans, different areas of the brain appear to be active when tasks requiring either STM or LTM are required. (E) Beardsley (1997) found that that the pre-frontal cortex is active when individuals are involved with tasks involving short-term memory. Squire et al, (1992) found that the hippocampus is active when long-term memory is engaged. (S) The different brain localisation when using either the STM or LTM shows that the parts of memory are in different parts of the brain, thus supporting the concept of distinct memory stores as proposed by Atkinson and Shiffrin.

Evaluate the MSM (challenging research)

(P) Other researchers demonstrated that memory is a product of processing information, and not maintenance rehearsal. (E) Participants were asked questions about stimulus words at different processing 'levels'. The words with questions that required a 'shallow level' of processing, for example, "is the word printed in capital letters" were less likely to be recalled that words with questions that required a 'deep level' of processing, for example, "Is the word a type of fruit." (S) This demonstrates that how the information is processed is important to memory, and contradicts the original claim that for memories to be transferred into LTM, maintenance rehearsal (verbal repeating) is required. Thus giving doubt to some of the assumptions of the multi-store model.

Evaluate the MSM (fails to explain)

(P) The Multi-store model argues that the transfer of information between STM and LTM is via rehearsal (E) There is plenty of evidence from everyday life that information passes from STM to LTM without the need of maintenance rehearsal (S) Rehearsal may explain how information is passed from STM to LTM in memory studies in laboratories with lists of words, but does not indicate how LTMs are formed during our day to day existence. The 'levels of processing' theory offers a more thorough explanation of this.

Evaluate the MSM (applications)

(P) The Multi-store model of memory can be used to give a greater understanding of how memory works, this can be helpful to people who rely heavily on their memories, such as students. (E) The model informs students that to pass information into a permanent store, they need to repeat the rehearsal of the information required. Just reading it once would not be considered effective rehearsal, according to the model (S) The model confirms the importance of effective revision if students want to do well in exams, and is therefore a useful model

Describe the long term memoy

LTM refers to the potentially permanent memory store which has a vast capacity and where memories can last for many years. People can store information about childhood, information about the world, and memory of how to do things.

Evaluate the research into the capacity of the STM

Miller found that chunking information could increase the number of items remembered, so we should think of capacity of STM as 7 'chunks' of information. However, subsequent studies have shown that some chunks are easier to remember than others, and if the chunks of information become too large, they are forgotten easily. Other research has found that there are widely differing individual differences, with some people being able to recall up to 20 chunks from their STM if they had what was considered advanced reading comprehension (Daneman and Carpenter, 1980) Information about the capacity of STM is useful for teachers, students and anyone else who needs to know the cognitive limitations or people.

Describe the research into the duration of the STM

Peterson and Peterson (1959) investigated how long simple information stays in short term memory (STM) without repetition. Procedure:On each trial the participants saw a trigram, which consisted of three consonants (e.g. BVM, CTG). A different trigram was used for each trial. They were asked to recall each trigram after a delay of seconds: 3,6,9,12,15 or 18. Once they were shown the trigram they had to perform an interference task, which prevented repetition of the trigram in STM. They were shown a random three digit number (e.g.866, 532) and had to count backwards from it in threes. After the appropriate time delay the trigram had to be recalled. Findings:The longer the time delay, the more the forgetting occurred in STM. After 3 seconds 90% of the trigrams were recalled, but after 18 seconds only 5% of the trigrams were recalled. Conclusion:Therefore it was concluded that nformation is lost rapidly from STM when there is no opportunity for repetition. Without repetition, STM lasts for little longer than 18 seconds. (most textbooks refer to 15-30 seconds duration)

Describe the research into coding in the STM

Short-term memory - Coding - Baddeley 1966 Participants were divided into groups (independent groups design) and given different lists of words to learn: Acoustically similar words (they sound the similar) e.g. man, mad, map Acoustically dissimilar words e.g. pen, day few Semantically similar words (they mean similar things) e.g. great, big, large Semantically dissimilar words e.g. hot, old, late In the short term memory condition they had to recall the words in the correct order immediately after hearing them. Results: In STM, recall of acoustically similar lists were remembered poorly, with a correct recall of about 10%. With the other lists, accurate recalled was much better, between 60% - 80%, with acoustically dissimilar words recalled the best. Conclusion: as acoustically dissimilar words were recalled more accurately than acoustically similar words, there must be some acoustic confusion during recall, which suggests that coding is acoustic. As there was little difference in recall for the semantically similar and dissimilar words, this would suggest that meaning is not the coding used in STM

Describe the short-term memory

Short-term memory refers to the information that we are currently aware of or thinking about. The information found in short term memory comes from paying attention to sensory memories. Short-term memory is very brief. When short-term memories are not rehearsed or actively maintained, they last mere seconds (15-30 approximately). Short-term memory is limited, with the amount of information held at any one time in single digits

Describe the supporting evidence for the capacity of the sensory register

Sperling (1960) flashed grids of letters in 3 x 4 format on screens for 1/20th of a second. Participants had to recall the letters from a specified row as indicated by a high pitch (top row) medium pitch (middle row) or low pitched (bottom row) tone. Recall of the specified row was high, suggesting that all the letters in the grid had been available in the participants' sensory register. (v long version of this in supplemetary pack ask angie if we need to kno all of it)

Describe research into the capacity of the LTM

Standing et al, (1970) gave participants a single presentation of a sequence of 2560 photographs for 5 or 10 seconds per picture. Even after 36 hours, participants could identify the correct photo when paired with a new scene approximately 90% of the time. This shows that a vast amount of material can be stored in LTM, at least in picture form, and gives support for the argument that LTM is probably an unlimited store. Anokhin (1973) calculated that no human has been born that has used the total capacity of his or her brain. He claimed that the number of neuronal connections possible would be approximately 1 followed by 15 .5 kilometres of noughts. This shows that there are vast numbers of new connections that can be made, therefore human memory is extremely large (limitless?)

Describe coding in the sensory register

There is very little coding in the sensory register. Information enters the memory system through our senses, and it is thought that everything we see, hear, touch, smell and taste enters sensory memory (sensory register) and remains in its raw form. There are different registers of each sense, for example. Iconic register: memory for visual information Echoic register: memory for auditory information Haptic register: memory for touch

Describe the duration of the LTM

This is dependent of the person's life span, as memories can last up to a life-time. Information that is processed at a deep level is likely to be remembered for longer, and memories based on skills rather than facts tend to be remembered better.

Evaluate research into the duration of the LTM

This research does have mundane realism, as the participants were using their everyday memories for faces. It is also supported by research into LTM for olfactory (smell) information, as Goldman and Seamon (1992) found that there was reasonable recognition of smells from participant's childhoods, thus there is reliability in the findings across the senses.

Describe the supporting evidence for duration of the sensory register

Treisman (1964) presented identical information to both ears through headphones but with a slight delay. At 2 seconds or less, participants could state that the messages were identical. After 2 seconds, this task became more difficult and errors were made. This suggests an echoic memory in SR of around 2 seconds. For Iconic memory, Walsh and Thompson (1978) flashed images of the letter 'O' twice with a very brief interval between each presentation. The researchers recorded the interval from which participants could only report that they saw a continuous stimulus. It was found that people had an iconic sensory store for about 500mseconds (half a second)