MSM FEATURES OF MEMORY
2.1.2 The Multi-Store Model of Memory (Atkinson and Shiffrin, 1968), including Short-Term Memory (STM) and Long-Term Memory (LTM), and ideas about information processing, encoding, storage, retrieval, capacity, and duration.
THE MSM AND FEATURES OF MEMORY
A key focus in cognitive psychology is the study of memory, with many introductory courses and specifications examining the Multi-Store Model (MSM) of memory proposed by Atkinson and Shiffrin. The MSM is often studied because it was the first comprehensive model to describe how memory operates, providing students with ample opportunity for positive and negative critiques.
Before Atkinson and Shiffrin's work, memory was primarily seen as a singular, unitary system. However, they hypothesised that memory is not one single entity but consists of three distinct stores: the Sensory Register, Short-Term Memory (STM), and Long-Term Memory (LTM). This idea revolutionised our understanding of how we encode, store, and retrieve information, laying the foundation for modern memory research.
With this background, we will begin our exploration of memory research by examining how theories like the Multi-Store Model challenged the traditional views of memory and paved the way for new approaches to understanding cognition and the brain.But first, we need to have some subject-specific terminology:
KEY WORDS
SENSORY REGISTER/MEMORY (ICONIC, ECHOIC, HAPTIC, OLFACTORY, GUSTATORY): The Sensory Register is the initial stage of memory that captures sensory information from the environment for a brief period. It includes:
Iconic Memory: Visual sensory memory (images and visual stimuli).
Echoic Memory: Auditory sensory memory (sounds).
Haptic Memory: Tactile sensory memory (touch).
Olfactory Memory: Memory for smells.
Gustatory Memory: Memory for tastes.
SHORT-TERM MEMORY (STM): Short-Term Memory refers to the temporary storage of information that is actively being processed. It typically holds a limited amount of information (around 7 items) for a short duration (approximately 18-30 seconds).
LONG-TERM MEMORY (LTM): Long-Term Memory is the continuous storage of information, which can last from a few minutes to an entire lifetime. It has a much larger capacity compared to STM and can store different types of information (e.g., declarative, procedural).
TRANSFER OF STM TO LTM: The process through which information moves from Short-Term Memory to Long-Term Memory. This typically requires rehearsal and encoding, where information is processed deeply enough to be stored for the long term.
FORGETTING THROUGH RETRIEVAL FAILURE: A type of forgetting that occurs when information is stored in Long-Term Memory but cannot be accessed. Retrieval failure often occurs due to a lack of retrieval cues or context.
LINEAR DIRECTION: In the context of memory models, a linear direction refers to the sequential process by which information moves through different memory stores—first to the sensory register, then to STM, and finally to LTM.
FORGETTING THROUGH DISPLACEMENT: Forgetting Through Displacement occurs when new information pushes out older information from Short-Term Memory due to its limited capacity.
UNITARY STORE: A Unitary Store is a memory model concept suggesting that memory is stored in a single, undifferentiated store rather than separate types (e.g., no division between STM and LTM).
MULTIPLE STORES: In contrast to a unitary store, Multiple Stores refer to models of memory that suggest distinct types of memory storage (e.g., Sensory Memory, Short-Term Memory, and Long-Term Memory), each with different characteristics.
REHEARSAL LOOP: The Rehearsal Loop is the process of repeatedly mentally repeating or verbalising information to keep it in Short-Term Memory or to transfer it to Long-Term Memory.
ENCODING: Encoding is the process of transforming sensory input into a form that can be stored in memory. It is how information is prepared to be stored in either Short-Term or Long-Term Memory.
CAPACITY: Capacity refers to the amount of information that can be held in a particular memory store. For instance, STM has a limited capacity (around 7 items), whereas LTM is thought to have a virtually unlimited capacity.
DURATION: Duration is the length of time information can be stored in a memory system. For example, STM has a short duration of around 18-30 seconds, whereas LTM can retain information for a much longer time, potentially a lifetime.
ACOUSTIC ENCODING: Acoustic Encoding is the process of converting information into sound patterns for storage in memory, often used in STM.
SEMANTIC ENCODING: Semantic Encoding is the encoding of information by its meaning, making it easier to recall. This type of encoding is more common in LTM.
VISUAL ENCODING: Visual Encoding is the process of converting visual information (e.g., images, colours) into a memory trace for storage. This type of encoding is often used in both sensory memory and STM.
AMNESIA: Amnesia is a condition characterised by a significant loss of memory, often affecting one’s ability to remember past events (Retrograde) or form new memories (Anterograde).
Causes:
Brain injury or trauma (e.g., concussion).
Neurological conditions (e.g., Alzheimer’s disease).
Psychological events (e.g., extreme stress or trauma).
ANTEROGRADE AMNESIA: Anterograde Amnesia is the inability to form new memories after the onset of an amnesia-causing event. While a person can still recall past events, they struggle to retain new information.
Causes:
Damage to the hippocampus or related brain areas (often due to traumatic brain injury, stroke, or certain drugs/alcohol abuse).
Diseases like Alzheimer’s that affect the brain's memory systems.
RETROGRADE AMNESIA: Retrograde Amnesia is the loss of access to memories that were formed before the onset of the amnesia-causing event. It can affect recent memories or even older ones, depending on severity.
Causes:
Traumatic brain injury (e.g., concussion, surgery).
Psychological trauma or events leading to memory repression.
Neurological damage (from conditions like encephalitis or Alzheimer’s disease).
MEMORY FAILURES AND CAUSES
DISPLACEMENT: The process where new information pushes out older information from Short-Term Memory (STM) because of its limited capacity.
Cause: Happens often when trying to memorise many items at once, leading to forgetting the earlier ones.
TRACE DECAY: The loss of memory if it is not accessed or rehearsed. Trace Decay is a theory of forgetting in which memory traces (the physical changes in the brain that represent memories) fade and weaken over time when they are not actively rehearsed or use
Cause: Natural degradation of memory traces in both Short-Term and Long-Term Memory.
RETRIEVAL FAILURE: The inability to access a memory that is stored in Long-Term Memory (LTM), often due to insufficient cues or lack of context.
Cause: Sometimes known as the "tip-of-the-tongue" phenomenon, it can occur due to insufficient rehearsal or improper encoding, making the memory hard to retrieve when needed
2.1.2 The Multi-Store Model of Memory (Atkinson and Shiffrin, 1968), including Short-Term Memory (STM)and Long-Term Memory (LTM), and ideas about information processing, encoding, storage, retrieval, capacity, and duration.
ATKINSON AND SHIFFRIN’S THREE TYPES OF MEMORY STORES
According to Atkinson and Shiffrin’s Multi-Store Model, memory comprises three distinct stores: the Sensory Register, Short-Term Memory (STM), and Long-Term Memory (LTM). Each store plays a unique role in processing and storing information.
SENSORY REGISTER
The Sensory Register is an unconscious memory store that briefly holds sensory information from the environment, creating an unconscious representation of our world. It constantly receives input from all our senses (e.g., sight, sound, touch).
You are typically unaware of this information unless you pay attention to it. For instance, you may not notice how your foot feels until you suddenly step on a pin. This sensation captures your attention, moving the information from the sensory register to STM, where it becomes conscious.
SHORT-TERM MEMORY (STM)
STM is where the information given attention is brought to conscious awareness and actively processed. At this stage, the stimuli become something we can think about or temporarily hold in our minds.
LONG-TERM MEMORY (LTM)
LTM stores information over extended periods, sometimes for a lifetime. It encodes information based on meaning—a process known as semantic encoding—which allows for deeper processing and long-term retention.
DIFFERENCES BETWEEN THE STORES: FEATURES OF EACH MEMORY STORE.
To prove their theory—that memory is not one store but three—Atkinson and Shiffrin had to demonstrate that STM, sensory memory (SM), and LTM differ fundamentally, such as being located in different parts of the brain. The most common way to prove these differences is to compare them based on duration, capacity, and encoding. Understanding these distinctions helps reinforce the idea that memory comprises three separate, interconnected stores.
CAPACITY IN MEMORY STORES
Capacity refers to the amount of information that each memory store can hold. STM has a limited capacity, whereas LTM is thought to have a far larger, potentially unlimited capacity.
STM Capacity - Miller’s Study (1956): George Miller investigated the capacity of STM and found that people can generally hold around 7±2 items at a time (often referred to as "the magic number seven"). This suggests that STM has a limited capacity, making it necessary to use techniques like chunking (grouping information) to maximise storage.
MEMORY SPAN/DIGIT SPAN: Memory span, often assessed through digit span tasks, is the capacity of working memory to hold a sequence of items, typically numbers, in the correct order for a short period. A classic digit span task involves a person listening to or reading a series of numbers and then trying to repeat them back in the same order. The number of items that can be correctly recalled without mistakes is considered their "digit span."
Typical Span:
Research, like that of George Miller, suggests that the average person’s memory span is about 7 ± 2 items (between 5 and 9), meaning this is the usual limit for the number of discrete units or chunks one can hold in short-term memory (STM).
CHUNKING AND STM CAPACITY: Chunking is a strategy used to overcome the limited capacity of STM by grouping individual bits of information into larger, meaningful units or "chunks." This allows for more efficient use of memory resources, enabling one to remember more items than by trying to store each piece separately.
Example: Instead of trying to remember the digits "1, 9, 4, 5," which could be four separate items, one might chunk them into the year "1945." This transformation reduces the number of items from four to one.
Significance: Chunking helps extend the capacity of STM by grouping information meaningfully. A well-known example is how people often remember phone numbers in chunks (e.g., 123-456-7890).
DURATION IN MEMORY STORES
Duration refers to when information can be retained within each memory store without being lost or forgotten.
STM Duration - Peterson and Peterson (1959): Peterson and Peterson studied the duration of STM by giving participants trigrams (nonsense sequences of three consonants, like "JRG") to remember while counting backwards to prevent rehearsal. They found that STM was unable to retain the information after just 18-30 seconds, showing that STM duration is very short without rehearsal.
LTM Duration - Bahrick et al. (1975): Bahrick and colleagues examined the duration of LTM by asking participants to recall names and faces from their high school yearbooks. They found that even years later—up to 50 years—people could recall about 70% of their classmates' names and faces, suggesting that LTM has a long duration, potentially lasting a lifetime.
UNDERSTANDING ENCODING IN STM AND LTM
Many students find the concept of encoding challenging. Put, encoding is how information is transformed and stored in our memory systems—Short-Term Memory (STM) and Long-Term Memory (LTM). However, the way we encode information in each system differs:
STM encodes acoustically and visually, meaning it primarily stores sounds and images. For instance, if you're trying to remember a phone number briefly, you might repeat it aloud (acoustic encoding) or visualise the digits (visual encoding).
LTM, however, encodes information semantically, which means it stores the meaning of information rather than the exact details.
SEMANTIC VS SYNTAX EXAMPLE
To understand semantic encoding, let's compare it with syntax.
Syntax refers to the exact structure of words and sentences—the specific word-for-word phrasing of something. For example, memorising every word of the story "Goldilocks and the Three Bears" would be remembering the syntax.
Semantic memory, however, is remembering the gist or meaning of the story—essentially, understanding that "Goldilocks enters the bears’ house, eats their food, sits in their chairs, and falls asleep in their bed." The exact words are not retained, but the main idea or meaning is.
Encoding information semantically in LTM means that our memory is not an exact replication of the actual event but rather an interpretation of it. Our intelligence, attention, biases, and personal understanding influence this interpretation. So, when we recall an event, we recall what it meant to us rather than every detail.
BADDELEY’S STUDY ON DIFFERENT TYPES OF ENCODING
Baddeley conducted a study examining the recall of acoustically and semantically similar and dissimilar words to test how STM and LTM encode differently.
Acoustically Similar and Dissimilar Words:
Acoustically Similar words sound similar (e.g., man, map, mat, mad).
Acoustically Dissimilar Words do not sound alike (e.g., pen, tree, sun, shoe).
In the experiment, when participants were asked to recall acoustically similar words immediately (using STM), they struggled more than dissimilar words, suggesting that STM relies heavily on acoustic encoding and that words sounding alike can cause confusion.
Semantically Similar and Dissimilar Words:
Semantically Similar Words have similar meanings (e.g., big, large, huge, enormous).
Semantically Dissimilar Words have different meanings (e.g., small, red, tree, walk).
When participants were asked to recall semantically similar words after a delay (using LTM), they found it more difficult than recalling semantically dissimilar words. This indicates that LTM relies on semantic encoding and that words with similar meanings can be easily confused in LTM.
Baddeley (1966b): The influence of acoustic and semantic similarity on Long-Term Memory for word sequences.
AIMS
Baddeley aimed to investigate how Short-Term Memory (STM) and Long-Term Memory (LTM) encode information. Specifically, he wanted to see if STM encodes information acoustically (by sound) and if LTM encodes information semantically (by meaning).
PROCEDURE
Participants were presented with four lists of words:
Acoustically Similar: words that sound alike.
Acoustically Dissimilar: words that sound different.
Semantically Similar: words with similar meanings.
Semantically Dissimilar: words with different meanings.
For testing STM, participants had to recall the words immediately after hearing them. For LTM, there was a 20-minute delay before the recall to assess the retention of the words.
FINDINGS
STM Encoding: Participants had difficulty recalling acoustically similar words immediately, suggesting that STM relies heavily on acoustic encoding.
LTM Encoding: When recalling words after a delay, participants struggled more with semantically similar words, indicating that LTM relies on semantic encoding.
CONCLUSION FEATURES OF MEMORY
Baddeley's study demonstrated that STM and LTM use different encoding processes. STM tends to encode information acoustically, so you can repeat something to keep it in mind, while LTM encodes semantically, storing the meaning of information rather than the precise details. This distinction is crucial for understanding how we learn and remember different types of information over short and long periods.
QUESTIONS
What led to the rise of the Cognitive approach in psychology, and how did it differ from Behaviourism? (2 marks)
What are the four main methods cognitive psychologists use to investigate mental processes and brain functioning? (4 marks)
How did Atkinson and Shiffrin’s Multi-Store Model challenge earlier views of memory? (2 marks)
Explain how information is transferred from the Sensory Register to Short-Term Memory (STM). Provide an example. (2 marks)
What are the key differences between STM and LTM in terms of encoding, based on Baddeley’s study? (2 marks)
What did George Miller (1956) discover about the capacity of Short-Term Memory? (1 mark)
What did Peterson and Peterson (1959) demonstrate about the duration of STM? (2 marks)
How did Bahrick et al. (1975) study the duration of Long-Term Memory (LTM), and what did they find? (2 marks)
What is semantic encoding, and how does it differ from remembering syntax? Give an example from a well-known story. (2 marks)
According to Baddeley’s study, how do acoustically similar and semantically similar words affect recall in STM and LTM? (2 marks)
What are the three distinct stores in Atkinson and Shiffrin’s Multi-Store Model of memory, and what role does each play? (3 marks)
Why is the capacity of LTM considered difficult to measure empirically? (1 mark)
How do laboratory experiments contribute to understanding cognitive processes, and what is an example of such an experiment? (2 marks)
What limitations of Behaviourism led to the development of the Cognitive approach? (2 marks)
How does Cognitive Science and the development of AI models help us understand human memory processes? (2 marks)
What were the main aims of Baddeley’s study, and what aspect of memory was he trying to investigate? (2 marks)
How did the procedure of Baddeley’s study differ when testing Short-Term Memory (STM) versus Long-Term Memory (LTM)? (2 marks)
According to Baddeley’s findings, what were the key differences in how STM and LTM encode information, and what conclusion did he draw from this? (2 marks)
THE MULTISTORE MODEL OF MEMORY
IN SHORT IF YOU CAN DESCRIBE THE MODEL ABOVE THEN YOU KNOW THE MULTISTIRE MODEL OF MEMORY
MSM DESCRIPTION
Before the 1960s, understanding of cognitive processes like memory was limited. The focus at that time was on behaviourism, which ignored mental processes, thinking the brain’s internal workings (or the ‘black box’) were irrelevant.
It was believed that memory was a single system in the brain.
In 1968, Atkinson & Shiffrin (A&S) suggested a different idea: memory consists of three separate stores, so their theory is called the Multi-Store Model (MSM). These three stores are sensory memory (SM), short-term memory (STM), and long-term memory (LTM). A&S argued that memory works as a structure, not just a process, and that information moves between these three stores in a fixed order: from SM to STM and then to LTM.
Sensory Memory (SM) is the first stop for all new information from the environment. It has different registers for the senses: sight (iconic), sound (echoic), touch (haptic), taste (gustatory), and smell (olfactory). Information here is raw and unprocessed, with a large capacity but only lasts for milliseconds. If attention isn’t paid, the information fades away and is forgotten.
Sensory memory captures everything happening around us, but we aren’t aware of most of it (e.g., every step we take or every sound we hear). It helps us make sense of our environment, giving us a feeling of time and space. Focusing on something specific (like a sound or a person) moves into STM, making us consciously aware of it. The sensory register operates without cognitive control, and attention is the key to moving information to the next store.
Short-term memory (STM) is where we become aware of information. It holds only a tiny amount of information for a short time (18-30 seconds) and has a capacity of around seven items. If we don’t rehearse the information, it can easily be forgotten.
To transfer information to LTM, we rehearse it in STM by repeating it (maintenance rehearsal) or processing it more deeply (elaborative rehearsal). If not rehearsed, information is lost through displacement (pushed out by new info) or trace decay (fades away).
Long-term memory (LTM) is like an archive for all memories, unlimited capacity and potential to last a lifetime. Retrieval happens when information from LTM passes back into STM.
While STM mainly uses sound-based encoding (acoustic), LTM stores information based on its meaning (semantic).
EXPLAINING A01 AND A03 IN EDEXCEL PSYCHOLOGY
Edexcel Psychology's essays are divided into three main components: A01, A02 and A03. Think of it as having two distinct roles: being a reporter for A01 and a critic for A03 (we will discuss A2 later).
A01 = Description and Reporting
A01 is about describing the theory or research—clearly explaining the ideas, processes, and findings without adding your opinion. It’s like being a reporter, where you stick to the facts and provide a detailed overview of the subject matter. For example, you might describe Atkinson and Shiffrin’s Multi-Store Model by outlining the three memory stores: Sensory Register, Short-Term Memory (STM), and Long-Term Memory (LTM). Alternatively, discussing Baddeley's study, you would focus on the aims, procedure, findings, and conclusions (using APFC). You do not critique or evaluate—your role is to inform.
A03 = Evaluation and Critique - both positive and negative
A03 is where you evaluate the theory or research, becoming more of a critic. This means that, rather than just describing, you assess the strengths and limitations of the study and its implications. You’re demonstrating your understanding of how robust the research is, considering factors like validity, reliability, and generalizability. In the context of Baddeley’s study, for instance, you might discuss whether the study effectively supports the distinction between STM and LTM encoding or whether there were limitations in how the research was conducted.
PUTTING IT TOGETHER IN AN ESSAY
In an Edexcel essay, you first present the A01 content, describing the theory or research in a structured way. After thoroughly covering this, you then move on to A03, where you critique and evaluate what you have described. This helps balance the essay by showcasing your knowledge of the subject and your critical thinking skills.
In future lessons, we will delve deeper into A03 evaluation, where you'll learn to assess how credible and robust the research is, giving your essays a more analytical edge. In the meantime, look at the example below and see if you can recognise the difference between A01 and A03.
A01 ACCOUNT OF THE MULTI-STORE MODEL OF MEMORY (MSM)
The Multi-Store Model of Memory (MSM), proposed by Atkinson and Shiffrin (1968), is a theoretical framework suggesting that memory is composed of three distinct stores: the Sensory Register, Short-Term Memory (STM), and Long-Term Memory (LTM). Each of these stores has its features in terms of capacity (how much it can hold), duration (how long it can retain information), and encoding (how it processes information).
Sensory Register: Briefly holds sensory information from the environment in an unconscious state. It lasts for less than a second unless attention is given, at which point it transfers to STM.
STM: Holds information that has been attended to, lasting around 18-30 seconds without rehearsal. STM has a limited capacity of 7±2 items (Miller, 1956) and primarily encodes information acoustically.
LTM: Stores information for a long duration, potentially a lifetime. It has an unlimited capacity and primarily encodes semantically, meaning information is stored based on its meaning.
The MSM proposes that information moves linearly from the Sensory Register to STM and then to LTM through processes like attention and rehearsal.
SUPPORTING RESEARCH
A03 PEEL PARAGRAPHS EVALUATING MSM USING MEMORY FEATURES
PEEL Paragraph: Supporting Capacity Differences
Point: The MSM is supported by evidence that STM and LTM have different capacities.
Evidence: Miller (1956) found that STM has a capacity of 7±2 items, suggesting it is limited in the amount of information it can hold. In contrast, LTM is considered to have an unlimited capacity, as demonstrated by studies like Bahrick et al. (1975), which found that participants could recall names and faces from their high school yearbooks up to 50 years later.
Explain: These capacity differences between STM and LTM support the MSM's idea that memory comprises separate stores with distinct features.
Link: Therefore, evidence clearly distinguishing between the capacities of STM and LTM strengthens the MSM.PEEL Paragraph: Supporting Duration Differences
Point: The MSM’s claim that STM and LTM have different durations is supported by research.
Evidence: Peterson and Peterson (1959) found that STM lasts only 18-30 seconds without rehearsal, indicating a short duration. In contrast, Bahrick et al. (1975) demonstrated that LTM can last for decades, highlighting its long-lasting nature.
Explain: The difference in durations between STM and LTM aligns with the MSM’s proposal that the two memory stores operate separately and serve different functions.
Link: Consequently, the research on memory duration validates the MSM's distinction between short-term and long-term stores.PEEL Paragraph: Supporting Encoding Differences
Point: The MSM is supported by evidence that STM and LTM encode information differently.Evidence: Research by Baddeley (1966) demonstrates that STM and LTM use different encoding types. He found that STM primarily encodes information acoustically, as participants struggled to recall words that sounded similar. In contrast, LTM encodes semantically, where participants found it difficult to recall words with similar meanings after a delay.
Explanation: This suggests that STM and LTM are distinct memory stores with different functions and encoding processes. The distinction supports the MSM's claim that STM and LTM are separate stores rather than just a single memory system.
Link: This supports the MSM's assertion that information is processed differently across STM and LTM, strengthening the model's validity in explaining how memory is structured and how information is transferred between stores
the varying accessibility of different memories.
TEST YOURSELF
https://player.quizalize.com/quiz/bd62fc82-375c-4eaf-86ea-eeb8d9ab3370
https://quizlet.com/gb/566072923/the-multi-store-model-of-memory-aqa-a-level-psychology-flash-cards/
