The multi-store model of memory

• The multi store model Suggests that memory is composed of 3 sub stores, the sensory register, short term memory and the long term memory, all of which differ in terms of capacity, duration and coding.
• a1= Firstly information from stimuli in our environment enters the brain via the senses, most of this information is then lost almost instantly via the process of spontaneous decay
• a2= However, if the person pays attention to something then that information can move into the short term memory, where unless it is rehearsed it is forgotten.
• a3= If it is rehearsed enough then the information can enter the long term memory where it can be recalled from, back into the STM for recall of the information.
• (+) Evidence to support the MSM comes from brain damage patients who have damaged one store without damaging the other. E.g the case study of KF who after an injury had lost the ability to recall recent information but still had an intact ability to remember older memories like his first day at school
• (+)These results suggest that KF had damaged his STM but not damaged 11 his LTM, thus supporting the Multi store models theory of memory being composed of different sub stores located differently within the brain.
• (-) However, the MSM has been criticised for being oversimplified in comparison to other models of memory. This is because the MSM suggests that the short term memory is only one single store, whereas the working memory model suggests that the short term memory alone is composed of multiple sub stores.
• (-) 2= These sub stores include the visuo-spatial sketchpad, responsible for processing visual and spatial information.
• (-) 3= phonological loop is responsible for processing auditory information
• (-) 4= both of these “slave systems” are overseen by the central executive which temporarily stores all information before deciding which of the two slave systems is required to process the information.
• (-)5= This may mean that the multistore model is a reductionist model of memory.
• Sperling investigated the capacity and duration of the sensory register by flashing a 3 by 4 grid of numbers for 50 milliseconds to the participants before asking them to recall either the top row, middle row, bottom row or all rows (indicated by a tone).
• Sperlings results- showed that when asked to recall the entire grid participants on average could only recall 4-5 numbers, however when asked to recall a specific row they could recall 3-4 numbers of any row
• Sperlings findings- suggest that initially the whole grid was in the participants sensory register, it is just forgotten so quickly that the entire grid cannot be recalled. Demonstrating that the sensory register has a potentially unlimited capacity, just for a very short duration.
• Capacity of the STM - Jacobs Participants were presented with a string of letters or digits and had to repeat them back in the same order. The number of items increased until the participant failed to recall the sequence. Results found that the majority of participants recalled about 9 digits and about 7 letters. And the capacity increased with age during childhood.
• Jacobs concluded that STM has a limited storage capacity of 5-9 items. Miller also looked at the capacity of STM and suggested that it was 7 +/- 2 items. Like Jacobs he believed that the capacity of STM could be increased with ‘chunking’
• jacobs

  was a lab experiment it was high in control of all variables, which makes it easy to replicate and check the reliability of the findings. However, because the setting is artificial, results may lack ecological validity i.e results may not generalise to real life memory
• Duration of the STM - Peterson Participants were shown nonsense trigrams and asked to recall them after either 3,6,9,12,15,18 seconds. During the pause they were asked to count back in 3s from a given number, this acted as an ‘interference task’ to prevent them from repeating the letters internally. Results found that after 3 seconds, 80% of trigrams where recalled Whereas after 18 seconds only 10% of trigrams where recalled
• peterson results suggest that when rehearsal is prevented, very little can stay in the STM for longer than 18 seconds.
• Who conducted research on the duration of long-term memory (LTM)?

  Bahrick
• What method did Bahrick use to investigate the duration of LTM?

  Field study method
• What were participants asked to identify in Bahrick's study?

  People from their high school yearbook
• How were participants tested in Bahrick's study?

  By matching photographs to a list of names of their old classmates
• What percentage of classmates could participants recall after leaving school for 14 years?

  90%
• What percentage of classmates could participants recall after 47 years of leaving high school?

  60%
• What do the results of Bahrick's study suggest about the duration of long-term memory?

  It could have a potentially unlimited duration
• How can the duration of long-term memory be enhanced according to the study?

  By presenting cues to help prompt the memory
• What were the key findings of Bahrick's research on long-term memory?

  • Participants recalled 90% of classmates after 14 years
  • Recall dropped to 60% after 47 years
  • Suggests long-term memory may have unlimited duration
  • Cues can enhance memory recall