A03

• Separate memory stores:

  One strength of Baddeley's study is that it identifies a clear difference between 2 memory stores. Later research showed that there are some exceptions to Baddeley's findings but the idea that STM uses mostly acoustic coding and LTM mostly semantic has stood the test of time. This was an important step in our understanding of the memory system, which led to the multi-store model
• Artificial stimuli:

  One limitation of Baddeley's study was that it used quite artificial stimuli rather than meaningful material. For example, the word lists had no personal meaning to PPs. So, Baddeley's findings may not tell us much about coding in different kinds of memory tasks, especially in everyday life. When processing more meaningful information, people may use semantic coding even for STM tasks. This suggests that te findings from this study have limited application
• A valid study:

  One strength of Jacob's study is that it has been replicated. The study is a very old one and early research in psychology often lacked adequate controls. For example, some PP's digit spans might have been underestimated because they were distracted during testing (confounding variable). Despite this, Jacobs' findings have been confirmed by other better controlled studies since (e.g. Bopp and Verhaeghen). This suggests that Jacob's study is a valid test of digit span in STM
• Not so many chunks:

  One limitation of Miller's research is that he may have overestimated STM capacity. Cowan reviewed other research and concluded that the capacity of the STM is only about 4 (+/- 1) chunks. This suggests that the lower end of Miller's estimate (5 items) is more appropriate than 7 items
• Meaningless stimuli in STM study:

  One limitation in Peterson and Peterson's study is that the stimulus material was artificial. The study is not completely irrelevant because we do sometimes try to remember fairly meaningless material (e.g. phone numbers). Even so, recalling consonant syllables does not reflect most everyday memory activities where what we are trying to remember is meaningful. This means the study lacked external validity
• High external validity:

  One strength of Bahrick et al.'s study is that it has high external validity. This is because the researchers investigated meaningful memories (i.e. of people's names and faces). When studies on LTM were conducted with meaningless pictures to be remembered, recall rates were lower (e.g. Shepard). This suggests that Bahrick et al.'s findings reflect a more 'real' estimate of the duration of LTM
• One strength of the MSM is support from studies showing that STM and LTM are different. For example, Baddeley found that we tend to mix up words that sound similar when we are using our STM. But we mix up words that have similar meanings when we use our LTMs. Furthermore, support comes from the studies of capacity and duration of STM and LTM. These studies clearly show that STM and LTM are separate and independent memory stores, as claimed by the MSM
• Counterpoint:

  Despite such apparent support, in everyday life we form memories related to all sorts of useful things - peoples faces, their names, facts, places. But many of the studies that support the MSM used none of these materials. Instead, they used digits, letters (Jacobs), and sometimes words (Baddeley). They even used consonant syllables that have no meaning (Peterson and Peterson). This means that the MSM may not be a valid model of how memory works in our everyday lives where we have to remember much more meaningful information
• MSM


  Multi-store model
• One limitation of the MSM is evidence of more than one STM store
• STM


  Short-term memory
• Client referred to as KF


  • Had a clinical memory disorder called amnesia
• KF's STM for digits was very poor when they were read out loud to him


  But his recall was much better when he read the digits to himself
• Further studies of KF (and others) showed that there could even be another short-term store for non-verbal sounds (e.g. noises)
• This evidence suggests that the MSM is wrong in claiming that there is just one STM store processing different types of information (e.g. visual, auditory, etc)
• Elaborative rehearsal


  Linking the information to your existing knowledge, or thinking about what it means
• Elaborative rehearsal


  Needed for long-term storage
• Information can be transferred to LTM without prolonged rehearsal
• Prolonged rehearsal


  Not needed for transfer to LTM according to MSM
• MSM


  Multi-store model
• The type of rehearsal is more important than the amount according to Craik and Watkins
• The MSM does not fully explain how long-term storage is achieved
• Atkinson and Shiffrin's MSM


  Based on research evidence that showed STM and LTM to be single memory stores, separate and independent from each other
• There is a lot of research evidence that LTM, like STM, is not a single memory store
• Types of LTM


  • Memories of facts about the world
  • Memories of how to ride a bike
• There is more than one type of STM and more than one type of rehearsal
• MSM


  • An oversimplified model of memory
• The MSM is not worthless and should not be abandoned
• The MSM created the basis for future models to expand from
• HM (Henry Molaison) and Clive Wearing


  • Episodic memory severely impaired due to brain damage
  • Semantic memory relatively unaffected
  • Procedural memory intact
• HM could not recall stroking a dog half an hour earlier but he did not need to have the concept of 'dog' explained to him
• Clive Wearing (a professional musician) knew how to read music, sing and play the piano
• This evidence supports Tulving's view that there are different memory stores in LTM - one store can be damaged but other stores are unaffected
• Studying people with brain injuries

  • Can help researchers understand how memory is supposed to work normally
  • Major limitation is lack of control of variables
  • Brain injuries experienced by participants were usually unexpected
  • Researcher had no way of controlling what happened to the participant before or during the injury
  • Researcher also has no knowledge of the individual's memory before the damage
  • Without this, it is difficult to judge exactly how much worse it is afterwards
  • Lack of control limits what clinical studies can tell us about different types of LTM
• Case studies

  Not generalisable, cannot generate nomothetic laws for whole population, individual differences
• Understanding types of LTM


  • Allows psychologists to help people with memory problems
  • As people age, they experience memory loss specific to episodic memory - it becomes harder to recall memories of personal events/ experiences that occurred relatively recently though past episodic memories remain intact
• Intervention to improve episodic memories in older people


  Trained PPs performed better on a test of episodic memory after training than a control group
• Distinguishing between types of LTM enables specific treatments to be developed
• Episodic memory


  A 'specialised subcategory' of semantic memory (so essentially the same store)
• Some people with amnesia


  Have a functioning semantic memory alongside a damaged episodic memory