Memory AO1

• What does the multi-store model of memory consist of?

  1. Sensory register. 2. Short term memory (STM). 3. Long term memory.
• Who proposed the multi store


  Atkinson and Shiffrin (1968)
• What stores are unitary is the multi-store model of memory?


  STM and LTM.
• What happens in the sensory register in the multi-store model of memory?

  Environmental stimuli enters the sensory register.--> when attention is paid to something in the environment, it is then converted to short-term memory.--> If not then information is lost through decay.
• What happens in the STM store of the multi-store model of memory?

  Once in the STM store: --> maintenance rehearsal(loop) occurs and eventually such repetition will allow information to be transferred to LTM. --> If prolonged rehearsal doesn't occur information is lost through decay and displacement.
• What happens in the LTM store of the multi-store model of memory?

  When information is in LTM it can be retrieved back into STM, if not then its lost through decay and interference.
• Maintenance rehearsal


  Repetition of words in a 'loop' that keeps information in STM.
• Elaborative rehearsal


  Prolonged repitition where material is passed into LTM from STM.
• Coding


  The format in which information is stored in the various memory stores.
• Capacity


  The amount of information that can beheld in a memory store.
• Duration


  The length of time information can be held in a memory store.
• Baddeley (1966) aim


  To investigate the coding of STM & LTM.
• Baddeley (1966) procedure


  - He have different lists of words to four groups of participants to remember.

  - Group 1: acoustically similar words.

  - Group 2: acoustically disimilar words.

  - Group 3: semantically similar words.

  - Group 4: semantically disimilar words.

  - Participants were shown the words and asked to recall them either immediantely (from STM) or after 20 minutes (from LTM).
• Baddeley (1966) findings


  - When recalling from STM, the group with acoustically similar words did the worst.

  - When recalling from LTM, the group with semantically similar words did worst.
• Baddeley (1966) conclusions


  - STM is acoustically coded.

  - LTM is semantically coded.
• Jacobs (1887) aim


  To investigate the capacity of STM
• Jacobs (1887) procedure


  - He measured digit span.

  - Researcher read out four digits and the participant had to recall them out loud in the same order.

  - If this is correct, the researcher reads out five digits and so on until the participant cannot recall the order correctly.

  - This indicates the individuals digit span.
• Jacobs (1887) findings


  - Mean span for digits across all participants was 9.3 items.

  - Mean span for letters was 7.3.
• Jacobs (1887) conclusions


  STM has a capacity of 5-9 items.
• Peterson and Peterson (1959) aim


  To investigate the duration of STM.
• Peterson and Peterson (1959) procedure


  - Tested 24 students in 8 trials.

  - On each trial the student was given a consonant syllable (such as YCG) to remember.

  - They were also given a 3-digit number.

  - The student counted backwards from this number until told to stop.

  - On each trial they would stop after varying period of time: 3, 6, 9, 12, 15, or 18 seconds.
• Peterson and Peterson (1959) findings

  - After 3 seconds, average recall was 80%.

  - After 18 seconds, average recall was 3%.
• Peterson and Peterson (1959) conclusions

  Duration of STM is 18 seconds, unless maintenance rehearsal occurs.
• Why were students told to count backwards from a 3-digit number in Peterson and Peterson's procedure?

  To prevent maintenance rehearsal of the consonant syllable (which would increase the duration of STM memory for the syllable).
• Bahrick et al. (1975) aim


  To investigate the duration of LTM.
• Bahrick et al. (1975) procedure


  - Studied 392 american participants aged between 17 and 74.

  - High school year books were obtained from participants or directly from some schools.

  - Recall was tested in various ways.

  - (1) photo-recognition test, consisting of 50 photos, some from the participants year books.

  - (2) free recall test where participants recalled all the names of their graduating class.
• Bahrick et al. (1975) findings


  - Participants tested within 15 years of graduation were 90% accurate in photo recognition.

  - After 48 years, recall declined to about 70% for photo recognition.

  - Free recall was less accurate than recognition: 60% after 15 years and 30% after 48 years.
• Bahrick et al. (1975) conclusions


  LTM may last up to a lifetime for some material.
• Capacity of sensory register

  Very large (Sperling)
• Coding of sensory register


  Modality-specific (different for every sense)
• Duration of short term memory

  0-18 seconds (Peterson and Peterson)
• Capacity of short term memory


  - 5-9 items (Jacobs)

  - 7+or-2 items (Miller)
• Encoding of short term memory


  Mainly acoustic (Baddeley)
• Duration of long term memory

  Unlimited (Bahrick)
• Capacity of long term memory

  Unlimited (Linton)
• Encoding of long term memory


  Mainly semantic (Baddeley)
• Types of long term memory

  Procedural, semantic, and episodic.
• What types of long term memory are implicit?


  Procedural
• What types of long term memory are explicit?


  Episodic and semantic
• Procedural memory


  An implicit LMT store for our knowledge of how to do things. This includes our memories of learned skills, i.e. memory of motor skills.