The Multi-Store Model

• The multi-store model of memory


  The MSM distinguishes between the separate stores of sensory, short-term and long-term memory and describes how information passes through these memory stores in a linear/sequential way.
• The sensory register 


  the first and most immediate form of memory we have. This takes in sensory information through the five senses. The sensory register therefore holds what you can currently see, hear, smell, taste and touch. If this sensory information is paid attention to, it is transferred from the sensory register to short-term memory.
• Short-term memory (STM)


  holds a small amount of information in mind in an active, readily available state. It is the information we are currently aware of or thinking about. Maintenance rehearsal in STM occurs when we rehearse (repeat) material to ourselves over and over again. This will keep the information in our STM via the rehearsal loop but if it is rehearsed for long enough it passes into LTM.
• Long-term memory (LTM)


  holds memories indefinitely. LTMs can be brought back into STM through retrieval (e.g. when recalling a memory from your childhood).
• Coding 


  The way in which information is stored in memory e.g. acoustically (by how it sounds), visually (by how it looks) or semantically (by what it means). For example, imagine you are thinking of a doughnut. You can code this acoustically by repeating the word aloud, you can code it visually by thinking about what a doughnut looks like, or you can code it semantically by applying meaning to it e.g. doughnuts are Homer’s favourite food.
• Capacity


  The amount of information that can be held in memory. The greater the capacity, the more amount of information that can be held in memory.
• Duration


  The length of time information can be held in memory. The greater the duration, the longer the information can be held in memory.
• The Sensory Register

  • Coding = Modality specific. This means that information is stored in a raw, unprocessed form with separate

  sensory stores for our different senses. For example, the iconic store is where visual information is coded visually

  while the echoic store is where auditory information is coded acoustically (by sound).
• The Sensory Register

  • Capacity = Potentially unlimited
• The sensory register

  • Duration = Very brief – approximately 250 milliseconds.
• Who conducted the study in 1960 regarding memory recall?

  Sperling
• What was the procedure used in Sperling's study?

  • Task 1: Participants viewed a 3x4 grid of 12 letters for 50 milliseconds and recalled letters.
  • Task 2: Participants recalled specific rows of letters based on tones (high, medium, low).
• How long were participants shown the grid of letters in Task 1?

  50 milliseconds
• How many letters could participants remember on average in Task 1?

  1. 5 out of 12 letters
• What was the average recall of letters in Task 2 when participants heard the tones?

  3 out of 4 letters
• What do the findings of Sperling's study suggest about the sensory register's capacity and duration?

  • Capacity: Large, as indicated by recalling 3 out of 4 letters in Task 2.
  • Duration: Short, as information faded quickly in Task 1 when recalling 12 letters.
• Coding of short-term memory 


  Short-term memories are coded acoustically (by sound). This means that there may be confusion when recalling short-term memories that sound similar.
• Coding of long-term memory


  Long-term memories are coded semantically (by meaning). This means that there may be confusion when recalling long-term memories that have similar meanings.
• What was the aim of Baddeley's 1966 study?

  To investigate the coding of short-term and long-term memories
• What were the types of words used in Baddeley's study?

  • Acoustically similar words
  • Acoustically dissimilar words
  • Semantically similar words
  • Semantically dissimilar words
• How many words were participants shown in Baddeley's study?

  Five words
• What is an example of acoustically similar words used in the study?

  Cap and can
• What is an example of semantically dissimilar words used in the study?

  Poster and mouse
• How long after presentation were participants asked to recall words for short-term memory (STM) testing?

  20 seconds
• How long after presentation were participants asked to recall words for long-term memory (LTM) testing?

  20 minutes
• What was the main finding regarding short-term memory in Baddeley's study?

  Participants confused acoustically similar words more than others
• What was the main finding regarding long-term memory in Baddeley's study?

  Participants confused semantically similar words more than others
• What conclusions can be drawn from Baddeley's study regarding memory coding?

  • Short-term memories are coded acoustically
  • Long-term memories are coded semantically
  • Similar sounding words cause confusion in STM
  • Similar meaning words cause confusion in LTM
• Capacity of short-term memory 


  The capacity of STM is about 7+/-2 (between 5-9 pieces of information). The capacity of STM can be increased by chunking items together to reduce the number of items overall (e.g. chunking the letters of ‘E L B C Y I ’ into one word: ‘BIYCLE’
• Jacobs (1887)

  Aim: To investigate the capacity of STM.

  Procedure: Participants were given series of digits (e.g. 5, 3, 9,

  4, 1) and instructed to recall immediately in the correct order.

  As the test continued, the list got progressively longer (i.e.

  another digit was added).

  Findings: Participants could remember lists of up to 9 digits,

  with the average being 7 and the lower boundary being 5.

  Conclusion: Short term memory has a limited capacity of 7+/-2

  (between 5-9 items)
• Capacity of long-term memory 


  The capacity of LTM is potentially unlimited.
• Wagenaar (1986)

  Aims: To investigate the capacity of LTM.

  Procedure: Wagenaar tested his recall of 2,400 events that he had written in a diary over a number of years.

  Results: He found that he had excellent recall of these

  events.

  Conclusion: The capacity of LTM is very large.
• Duration of short-term memory

  Short-term memories last for approximately 18-30 seconds. Duration of short-term memories can be extended by verbal rehearsal through the rehearsal loop.
• What was the aim of the Peterson and Peterson (1959) study?

  To investigate the duration of short-term memory (STM).
• What was the procedure used in the Peterson and Peterson (1959) study?

  • Participants remembered consonant trigrams (e.g., JKD, MFN, RHT).
  • Rehearsal was prevented by counting backwards in threes.
  • After intervals of 3, 6, 9, 12, 15, and 18 seconds, participants repeated the trigram.
  • The percentage of correctly recalled trigrams was recorded.
• What were the consonant trigrams used in the Peterson and Peterson (1959) study?

  Examples include JKD, MFN, and RHT.
• How did the researchers prevent rehearsal in the Peterson and Peterson (1959) study?

  By asking participants to count backwards in threes from a specified number.
• What was the relationship between the time interval and the percentage of trigrams recalled in the Peterson and Peterson (1959) study?

  As the time interval increased, the percentage of trigrams recalled decreased.
• What percentage of trigrams could participants recall after 3 seconds?

  About 80% of the trigrams.
• What percentage of trigrams could participants recall after 18 seconds?

  About 10% of the trigrams.