Evaluate two models or theories of one cognitive process with reference to research studies.


  • State what you are doing in the essay 
    • The following essay aims to make an appraisal of two models of memory whilst weighing up the strengths and limitations of each. 
  • Define Memory 
    • Memory is defined to be the mental process of encoding, storing and retrieving information. 
  • Outline Memory Process 
    • Memory undergoes a series of stages in order to store its information. 
      1. Encoding process: incoming information is organized and transformed so it can be entered into memory 
      2. Storage process: involves entering and maintaining information in memory for a period of time 
      3. Retrieval process: involves recovering stored information from memory so it can be used 
  • State the different models/theories of memory
    There are three main types of models of memory that demonstrate how our memory processes work including the: 
    • Multistore Model (MSM) 
    • Working Memory Model (WM) 
    • Levels of Processing Model (LOP) 
  • State which Memory models you will be evaluating: 
    • As such, this essay response will be focussed on the evaluation of MSM & LOP memory models supported the arguments with relevant studies. 


Memory Model 1: The Multi-store Model of Memory

  • Describe the MSM: 
    • Proposed by Atkinson & Shiffrin (1968)
    • The multi-store model (MSM) consists of three memory stores: 
      • Sensory memory (SM) 
      • Short-term memory (STM) 
      • Long term memory (LTM) ... that is used for different tasks. 
  • Briefly explain the memory stores 
    • SM is... 
      • A storage system that holds information in a relatively unprocessed form for fractions of a second after the physical stimulus is no longer available – stores sensory characteristics of a stimulus. 
      • Plays a vital role in filtering out useless information, enabling us to focus our attention on important details. 
  • STM is...
  • A limited-capacity memory system for storing information for brief periods of time. 
  • A & S (1968) see STM as a temporary storage depot for incoming information after it receives and encodes information from the sensory memory. 

    • LTM is...:
      • Holds a vast quantity of information, which can be stored for long periods of time. 
      • Information kept here is diverse and wide-ranging, including all our personal memories, general knowledge and beliefs about the world, plans for the future, and where our knowledge about skills and expertise is deposited. 
    • These different memory stores differ from one another with regards to: 
      • Duration: how long information can be stored 
      • Capacity: how much information can be stored 
      • Coding: in what form information can be stored 

    • The Sensory Store 
        • Duration: decays rapidly 
        • Capacity: unlimited 
        • Coding: information is picked up by our senses and stored in this form 
      • Iconic: visual information enters the visual store 
      • Echoic: auditory information is handled by the auditory sensory store 
      • Haptic: information picked up via sense of touch 

    • Short Term Memory (Store) (STM/S): 
      • Duration: 15-30 seconds (Atkinson & Shiffrin, 1971) 
      • Capacity: limited; 7 ± 2units (Miller, 1956)
      • Coding: Acoustically (Baddeley, 1966) 
        • Information is lost unless it is rehearsed (via repetition) 

    • Long Term Memory (Store) (LTM/S):
      • Duration: Long-lasting (perhaps for a lifetime), proposed that it could last for 48 years (Bahrick et al, 1975)
      • Capacity: Unlimited
      • Coding: Primarily semantic (Baddeley, 1966); but also acoustic and visual
        • Information in the LTS can also be recalled via retrieval, bringing the information back to the STS 
    Supporting Study 1: Baddeley (1966) 

    Experiment 1: STM

    Introduce Study --> link to question:

    • A key researcher who investigated encoding, (which is the first and crucial process of creating memories, which allows the perceived item of interest to be converted into a construct/concept that can stored within the brain, and then recalled later from the STM or LTM) is by Baddeley (1966). 
    • To investigate encoding in the short term memory store 
    • Participants were given lists of words that were: 
      • acoustically similar (e.g. cat, mat...) 
      • acoustically different (e.g. pen, cow...) 
      • semantically similar (e.g. boat, ship...) 
      • semantically different (e.g. book, tree...) 
    • Their recall of the words was tested. 


    • In STM, better recall of acoustically different than acoustically similar words
      • more errors with similarly sounding words than distinctly sounding words 
    • Slightly better recall of semantically different words than semantically similar words’ 


    • In the STS, information is encoded acoustically because recall is affected by the sound of words

    Experiment 2: LTM 


    • To investigate encoding in LTM


    • Participants were given the same lists of words in the previous experiment for STM 
    • Their recall of the words was tested 


    • In LTM, no difference in recall of acoustically different and acoustically similar words 
    • Much better recall of semantically different words than semantically similar words 


    • In LTM, there is semantic encoding because recall is affected by meaning of words



    • Laboratory experiment
      • strict control over variables 
      • able to determine a cause-effect relationship between 
    • Laboratory experiment 
      • Lacks ecological validity
    • Task is unrealistic; does not reflect daily activity participants would do
    Connection of study to question

    This study supports the Multi-store model of memory as it shows that:

      • STM and LTM have different encoding processes:
        • STM: acoustic encoding 
        • LTM: semantic encoding 
      • Thus STM & LTM are separate stores. 
    • Applications of the MSMin studies relating to memory
      • Case studies into rare individuals demonstrating the MSM’S three stores are by Sacks and Shallice & Warrington.

    Supporting Study 3: Clive Wearing – Sacks (2007)

    Introduce Study link to question:

    • A study demonstrating memory processes between the STM and LTM in regards to the MSM is by Sacks on Clive Wearing (2007).

    • History:
      • Clive Wearing was a musician who got a viral infection encephalitis. 
      • This left him with serious brain damage in the hippocampus, which caused him memory impairment. 
      • He suffers from: 
        • anterograde amnesia impairment in ability to remember after a particular incident 
        • retrograde amnesia impairment in ability to remember before a particular incident

    • Findings:
      • Wearing still has ability to talk, read, write, and sight-read music (procedural knowledge) 
      • He could not transfer information from STM tLTM. 
      • His memory lasted 7-30 seconds, and he was unable to form new memories. 
    • Conclusion:
      • STM & LTM are separate stores 
      • STM has limited duration 
    • Strengths
      • Case study Realistic 
      • In-depth information 
    • Limitations 
      • Cannot be generalised to the whole population

    Connection of study to question
    This study supports the multi-store model because it shows that:

    • STM and LTM are separate stores
      • Wearing has STM intact but could not access LTM
    • STM has a limited duration
      •  Wearing could only use STM and he experienced time elapses of around 30 seconds. It also provides support for anterograde amnesia.

    Does not support the multistore Model of memory because:

    • Wearing had significant damage to his declarative memory, but his procedural memory was fully intact
    • This suggests that LTM is separated into declarative and procedural, rather than a single, unitary store as the MSM assumes.

    Supporting Study 4: Shallice and Warrington (1974) KFIntroduce 

    Study link to question:

    • Another demonstrating memory processes between the STM and LTM in regards to the MSM is by Shallice and Warrington on KF (1974). 
    • KF was in a motorcycle accident which impaired his memory
    • He could transfer information from STM tLTM 
    • He suffered problems with STM of different types of information
      • digit span was severely impaired
      • visual and auditory information (e.g. telephone ring) was unaffected
    • Findings suggest that:
      • STM & LTM are separate
      • STM is not required for LTM
      • There may be more than one STM store --> it is possible to suffer impairment of verbal information without affecting auditory information



    • Case study Realistic
    • In-depth information


    • Cannot be generalised to the whole population

    Connection of study to question
    This study supports the idea that memory stores are not unitary.KF suffered impairment of some types of STM (verbal) but had others fully intact (auditory) STM store is not unitary



    • Influential; early model that stimulated further research into memory processes 
      • Still accepted by most psychologists and is still widely used
    • Considerable evidence for demonstrating the existence of STM and LTM as separate memory stores
      • Differing via duration, capacity and coding
    • Provides support for anterograde amnesia
    • Based on considerable evidence and evidence for the model is gained from a variety of sources 
      • e.g. studies of brain damaged individuals
        • Whereby these studies support the distinction between STS and LTS
        • Some patients with amnesia suffer damage tLTM but not STM, and vice versa
          • As demonstrated by Shallice & Warrington (1970); Milner (1966); Baddeley (1997)
    Demonstrates insight into different memory processes, such as:
    • Demonstrates differences in encoding,
      • i.e. STM = STM = acoustic, LTM = semantic
    • Demonstrates differences in capacity,
      • i.e. STM = 7±2, LTM has no limits
    • Demonstrates differences in duration 
      • i.e. STM = approx. 20 seconds (Peterson & Peterson, 1959), LTM = 48 years (Bahrick et al.,1975).
    • Demonstrates in ability to form declarative or procedural memories by patients with brain damage, amnesia.


    • There is emphasis on the amount of information taken into memory
    • Focuses too much on the structure of memory systems rather than providing an explanation on how it works (functioning/ processing)
    • Reductionist*, oversimplifying memory processes (Eysneck & Keane, 1995) – too simple
      • Mechanical in transfer from one store to another
      • Memory processes are more complex and flexible 
        • *a form of explanation or approach to understanding complex things by simplifying (or reducing) them to their most basic parts.
    • Assumes that stores are single and unitary
    • Unlikely that the diverse information in LTM is contained in one, simple, unitary store in same form
      • Tulving (1972) suggests that LTM can be divided into episodic, semantic and procedural components, stored separately
      • Cohen & Squire (1980) suggest LTM is divided into 2:
        • Declarative memory: involves recollection of facts and events, includes episodic and semantic memory. 
        • Procedural memory: memories for how to do things.
    • Evidence from amnesia patients who have poor declarative knowledge with no damage to procedural knowledge 
      • Spiers et al. (2001) 
      • Clive Wearing Baddeley, 1997
    • Atkinson and Shiffrin (1968) focused almost exclusively on declarative knowledge and did not account for procedural knowledge in their model. 
      • Model suggests that rote rehearsal is the only way information transfers from STM tLTM 
        • Too simple 
        • Ignores any other factors such as effort and strategies people employ to remember things
    • Studies have questioned whether the more information is rehearsed, the more likely it is to be transferred tLTM
    • Rehearsal may be what occurs in laboratory experiments but this lacks ecological validity 
    • Most people rarely actively rehearse information in daily life, yet information is constantly transferred into LTM (Eysenck and Keane, 1995) 
      • Rehearsal is not as important as the MSM suggests 
      • Increased rehearsal is no guarantee that information will be stored in LTM 
    • MSM under-emphasises interaction between stores
      • transfer of information is strictly sequential
      • information stays in LTM until retrieved
    • Does not consider the possibility that LTM interacts and even directs other memory stores
      • Sensory what is important to pay attention 
      • STM helps rehearsal or meaningful chunking

    Memory Model 2: The Levels of Processing Model

    • Describe the LOP
      • Proposed by Craik & Lockhart (1972)
      • LOP predicts that how deeply people process information determines how well it is stored in memory
        • Deeper, meaningful processing creates stronger, longer-lasting memory traces.
        • Shallow processing leads to weaker memory traces
      • It states that memory is a by-product of processing information:
        • Maintenance rehearsal (repetition to hold information in STM) is shallow processing and leads to short-term retention of information.
          • As opposed to argument of MSM
        • Elaboration rehearsal (meaningful analysis (e.g. images, thinking, associations etc.) of information) leads to better recall.

    • State the three levels of processing
      • Structural (shallow) encode the physical qualities/appearance 
      • Phonological (intermediate) encode sound/auditory
      • Semantic (deep) encode meaning and associate it with existing knowledge

    Supporting Study 1: Hyde and Jenkins (1973)

    Introduce Study --> link to question:

    • A study investigating... is by Hyde & Jenkins (1973). 
    • ...’investigating’ whether people could remember without intentionally trying to, and whether deeper processing leads to better recall 
    • Participants were presented with auditory lists of 24 words 
    • Different groups of participants were asked to perform one of the following tasks requiring different levels of processing 
      • rating words for pleasantness 
      • estimate frequency with which each word is used in the English language 
      • detect occurrence of letters ‘e' and 'g' in any of the words 
      • decide part of speech appropriate to each word (e.g. noun, adjective) 
      • decide whether words fitted into a particular sentence frame 
    • Half participants were told in advance that they would be asked to recall words (intentional learning group) 
    • Other half were not (incidental learning group) 
    • Minimal differences in the number of words correctly recalled between the intentional and incidental learning groups.  
    • Recall was significantly better for words analysed semantically (e.g. rated for pleasantness) than words which had been rated more superficially (e.g. detecting 'e' and 'g') 


    • Maintenance rehearsal is not necessary for learning. 



    • Laboratory experiment 
      • strict control over variables 
      • able to determine a cause-effect relationship between 

    • Laboratory experiment 
      • Lacks ecological validity
    • Task is unrealistic; does not reflect daily activity participants would do
    Connection of study to question
    Thus study supports the LOP theory because it shows that:
    • semantic processing is deeper than structural and leads to better memory 
    • intention is unnecessary for retention
      • supports Craik and Lockhart's belief that retention is a by-product of processing

    Supporting Study 2: Craik and Tulving, 1975

    Introduce Study --> link to question:

    • A further study “investigating the effects of deep and shallow processing on memory recall” is by Craik & Tulving (1975).
    • “To investigate how deep and shallow processing affects memory recall”
    • Participants presented with a series of 60 words about which they had to answer one of three questions, requiring different depths of processing.
    • Participants were then given a long list of 180 words into which the original words had been mixed.
    • They were asked to pick out the original words.
    • Participants recalled more words that were semantically processed compared to phonemically and visually processed.
    • Semantically processed words involve deep processing which results in more accurate recall.
    • Laboratory experiment
      • strict control over variables 
      • able to determine a cause-effect relationship between 

    • Laboratory experiment 
      • Lacks ecological validity
    • Task is unrealistic; does not reflect daily activity participants would do
    Connection of study to question
    • The experimental method was used in this study because the researchers wanted to find a cause- effect relationship between the level of processing and memory recall.
      • This would not be able to be done using other research methods such as surveys or interviews.


    Overcomes criticisms of the Multistore Model as being too simple methods of remembering. LOP was very influential when first proposed.

    • It changed the direction of research and stimulated further research into memory Accounts for why some things are remembered better and for longer than others. LOP theory is useful in daily life as it shows how elaboration, which requires deeper processing, leads to better memory. It helps to understand processes at learning stage. Improvements on Multi-store model of memory:
      • Does not make strict distinction between STM & LTM
      • Does not regard LTM as simple storage unit, rather a complex processing system 
      • Encoding is not simple and straightforward
      • improvement on the MSM's account of transfer from STM tLTM
      • Focuses on mental processes rather than structures
    • Much research and evidence supporting the LOP theory's idea that deep processing aids memory.


    Lacks ecological validity

    •  all the evidence based on laboratory experiments LOP theory focuses on the processes rather than structures of memory.
    • Evidence (e.g. Clive Wearing, KF) supports memory structures of STM and LTM stores proposed by MSM.
    Major limitation difficult to define “deep” processing

    • It is vague and cannot be observed, making it hard to measure objectively
    • Baddeley (1990) – cannot independently assess depth
    • Circular definition deeply processed information will be remembered better, but the measure of depth is how well information is remembered.
    • LOP theory is descriptive rather than explanatory. Though later research has attempted to explain how and why deep processing is effective in aiding memory, the original theory did not provide a detailed explanation of this (Eysenck and Keane, 1995). Ordering of memory of LOP (semantic better than phonological better than structural) is not always supported by research.
    • Several studies have shown that deeper processing does not guarantee better memory. Participants usually spend more time and effort on the tasks requiring deeper processing. 
    • Type of processing, amount of effort and length of processing time are often confounding 
    • It is difficult to know that depth of processing alone influences memory 
    • Better memory may be due to more time or effort spent on processing; not deeper processing. Like the MSM, LOP theory is too simplistic; research indicates that memory is more complex and varied than depth and elaboration. 


    Multistore Model of Memory

    • Provides a good explanation of the memory structures 
    • Is also supported by a large amount of research 
    • However, it still requires further research to explain the processes involved in memory 
    • Needs to develop the model from its oversimplified explanations, to a more complex, and thus, accurate model of memory 
    Levels of Processing 
    • Provides a good description of the processes involved in memory 
      • But does not account for the structure of memory
    • Further research should be conducted to refine the theory
    • Development of the theory could be done to explain exactly how memory processes work and incorporate memory structures
    • Encoding refers to the active process of putting stimulus information into a form that can be used by our memory system. It requires you to form mental representations of information from the external world. 
      • Semantic Encoding – encoding information through its ‘meaning’ 
      • Acoustic Encoding – encoding information according to its ‘sound’ 
      • Visual Encoding – encoding information through its ‘visual’ aspects 
    • Storage refers to the process of maintaining information in memory. It requires short and long term changes in the structure of your brain. 
    • Retrieval is the active processes of locating and using information (remembering).