MSM & STM

• Coding


  The format in which information is stored in the various memory stores.
• Research on coding


  -Baddeley (1966) gave different lists of words to 4 groups to remember.-Either words that were acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar.

  When recalling from STM participants did worse with acoustically similar words -When recalling from LTM, they did worse with semantically similar words.
• Evaluation points for research into coding? (Baddely)

  +Separate memory stores (strength): later research showed that there are some exceptions to Baddely's findings. But the idea that STM uses mostly acoustic coding and LTM is mostly semantic has been proven right. -Artificial stimuli- ( weakness)
• Capacity


  The amount of information that can be held in a memory store
• Research on capacity

  -Jacobs-He found that the mean span for digits across all participants was 9.3 items, and the mean span for letters 7.3.

  Miller- made observations of everyday practice and found that things come in 7s, e.g. days of the week, music notes, etc
• Evaluation points of research into capacity (Jacobs + Miller)

  +A valid study (Jacobs')- Bopp et al replicated Jacobs' study to control confounding variables, and found the same results. -Overestimated (Miller)- Cowan reviewed other research and found that the capacity of STM is only about 4 chunks. This suggests that Miller's estimate is too high.
• Duration


  The length of time information can be held in memory.
• Research on duration

  -Peterson and Peterson- tested 24 pupils - They found that after 3 seconds, the average recall was 80%, and after 18 seconds it was 3%. They concluded that STM's duration may be about 18 seconds, unless the information is repeated over and over.

  -Bahrick et al- studied 392 participants aged 17-74. Participants had to either recall names of their graduating class

  Participants tested within 15 years of graduation were 90% accurate in photo recognition and 60% in free recall, 48 years of graduation were 70% accurate fir photo recognition and 30% for free recall.
• Evaluation points of research on duration (Peterson & Peterson+Bahrick)

  -Artificial stimuli (Peterson & Peterson)- recalling consonant trigrams does not reflect everyday memory, and the stimuli was meaningless. This means that the study lacked external validity. +High external validity (Bahrick et al)- Meaningful memories were investigated. When studies on LTM were conducted with meaningless pictures to be remembered, recall rates were lowered. (e.g. Shephard et al).
• Multi-store model (Atkinson and Shiffrin)


  -A representation of how memory works in terms of three stores called sensory register, short-term memory and long-term memory. -It also describes how information is transferred from one store to another, how it is remembered and how it is forgotten.
• Sensory register


  -The memory stores for each of our five senses, such as vision (iconic store) and hearing (echoic store).
• Short-term memory


  -Information in short-term memory is encoded mainly acoustically, and lasts about 18 seconds unless it is rehearsed, so it is more of a temporary store. (it can only contain a certain amount of items before forgetting occurs).-The capacity of STM between 5 and 9 items of information.
• Long-term memory


  -Potentially permanent store for information that has been rehearsed for a prolonged time, it is also coded semantically. -Psychologists believe that the duration may be up to a lifetime. -According to the MSM, when we want to recall information from LTM it has to be transferred back into STM by a process called retrieval.
• Strength of multi-store model of memory

  -Baddely found that we tend to mix up words that are acoustically similar when using our STMs, and words that are semantically similar when using our LTMs

  counterpoint- the stimuli used to test the stores were meaningless and did not reflect every day life.
• Weaknesses of the multi-store model of memory

  -More than one STM store- KF, who had amnesia's STM for digits was very poor, when read out loud, but recall improved when he read the digits himself

  Elaborative rehearsal- prolonged rehearsal- prolonged rehearsal is not needed for transfer to LTM. According to the MSM, quality is needed. But Craick and Watkins found the type of rehearsal more important. Elaborative rehearsal is needed for long-term storage, suggesting the MSM does not fully explain how long-term storage is achieved.