Coding, Capacity and Duration


Multi Store model of memory

Long term memory

  • Limitation of Baddeley
  • Used artificial stimuli rather than meaningful material
  • Word lists had no personal meaning to participants
  • Does not tell us much about coding in different kinds on memory tasks, especially with everyday life
  • When processing more meaningful information, people may use semantic coding even for STM tasks. This suggests that the findings from this study may have limited application

Capacity

Duration

  • Strength
  • Asking participants meaningful information as information was from participant lives, such as information about their classmates
  • More validity
  • The way we code information in a lab is very different to how we code information in real life
  • Very different to everyday coding
  • More likely to generalise how people study information in their real lives
  • High ecological validity

Coding


Sensory Register

  • Strength
  • Clive Wearing
  • Caught a disease, contracting amnesia
  • Following this he could only remember information for 20-30 seconds
  • Although, he was able to recall information from his past like his wife’s name though wearing was unable to transfer information from his STM to LTM, but he was able to retrieve information successfully
  • This study supports the ideas that memories are formed by passing information from one store to the next in a linear fashion and that damage to any part of the MSM can cause severe memory loss





Short term Memory

  • Limitation
  • The case of KF weakens the MSM
  • KF suffered from amnesia, and was able to recall visual information without difficulty, but had problems recalling verbally presented information
  • This suggests there is more than one type of STM store, so the MSM is too simplistic

Coding- Sensory and Semantic code, mainly acoustic
Capacity- 7+/-2 items
Duration- 18-30 seconds

Coding- Semantic- stored by meaning
Capacity- Unlimited
Duration- Lifetime or duration

Coding- Modality specific (Iconic-vision, sound-echoic)
Capacity- Huge
Duration- 250ms

How long a memory store can keep information in it, with a longer duration meaning memories can be kept for longer

Bahrick- Long term memory Duration


  • To find how the duration of the long term memory
  • Asked participants to recall graduating class names and recognition through photos

  • Asked participants 15 years after graduation and 48 years after graduation


  • 15 years, 60% recall and 90% recognition


    • 48 years, 30% recall and 80% recognition


  • Long term memory's last a lifetime or 48 years
  • Our recognition memory is better than our recall memory accuracy

Baddeley- Coding in short term memory


  • He asked particpants to remember list of words
  • Tested short term memory by recalling straight after hearing them
  • Tested long term memory by participants recalling 20 minutes after hearing them
  • Divided participants into four group
  • Semantically similar, Semantically dissimilar, Acoustically similar and Acoustically Dissimilar


  • He found that immediate recall was worse with acoustically similar because participants got the words confused
  • He found that after 20 minutes, recall was worse with semantically similar meaning's got confused
  • Information is coded acoustically in STM and semantically in LTM

The size of the information store

What format things are stored in

Miller- Short term memory capacity


  • He asked participants to remember letters


  • Participants group individual letters together into meaningful chunks
  • He found that participants could remember 7+/-2 chunked
  • Capacity of the short term memory is defined by the number of chunk, not number of individual items need to recall
  • Chunks improved the capacity of the STM

Jacobs- Capacity in Short Term memory


  • He asked participants to remember words and digits and repeat them in the correct order
  • He then increased the length's of the letters


  • He found that participants could remember 7+/-2 items of words and digits
  • Capacity of short-term memory is limited
  • Information can only travel through the stores in one direction
  • Atkinson and Shiffrin proposed that information flow is unidirectional and flows from the sensory register, to the short-term store, then to the long-term memory store
  • To transfer information from the sensory register to the short-term memory store we have to pay attention to it
  • To transfer information from the short-term memory store to the long-term memory store we have to rehearse it
  • Register information from the outside environment
  • 5 sense

Temporary active store, receiving information from the SR by passing attention, or from LTM by retrieval. Keeps information in STM (maintenance rehearsal) or passing information on to the LTM

  • Atkinson and shift
  • Information flow is unidirectional
  • Explain's how we transfer information across memory stores

Forgotten information is just not accessible. To use information is passed to STM (retrieval). Episodic, semantic and procedural