Memory

• What is memory?

  Memory is the input, the storage and retrieval of information
• What does MSMM stand for and who proposed it?

  Multi-Store Model of Memory, Attkinson & Shiffrin (1968)
• Outline 4 features of the MSMM

  • 3 different types of memory
  • Sensory register, STM & LTM
  • Linear model meaning it flows in one direction only
  • Each store can retain different info for different amount of time and way
• Capacity, Encoding and Duration?


  capacity - the amount of info to be held.

  encoding - the way the info can be stored.

  duration - the length of time the info can be stored.
• SPERLING (1960)

  Investigated sensory register, the ppts were shown grids of letters for less than 0.5 sec. The ppts recalled the first few letters but were aware that there were more letters in the grid. The attention is needed to pass info into the STM, the capacity is high and the duration is less than half a second (<0.5 sec)
• JACOBS (1887)

  Devised a technique to measure digit span. Digits read out. As new digits are added ppts are asked to recall previous ones plus the new ones after a pause. Mean span for digits: 9.3 and mean span for letters:7.3
• MILLER (1956)


  Chunking method - several pieces of ingo can be chunked together to form one piece of info. STM is 7 + or -2 chunks of info. There was a lack of control over time and location that may of influenced the results
• Sensory memory - CDE

  C - HIGH

  D - <= 0.5 secs

  E - 5 senses
• STM CDE


  C - 7+ OR -2

  D - 18-30 sec

  E - ACOUSTICALLY
• LTM CDE

  C - unlimited

  D - YEARS

  E - semantically (synonyms)
• Peterson and Peterson ( 1959)


  To investigate the duration of STM. Ppts were given trigrams and were asked to verbally complete along with distraction tasks by counting down in intervals of threes and then were asked to recall this piece of info. They found the duration was 18 - 30 seconds
• Evaluation of investigating the encoding of memory stores?

  The research involves artificial stimuli which could be less applicable to the real world. This means that we should be cautious about generalising findings to different kinds of memory tasks e.g more meaningful info people may use semantic coding for STM tasks
• Bahrick (1975)


  Investigated the duration of LTM using yearbooks and then were tested on free recall and cued recall (random 50 photos). Duration was found to be unlimited

  • had high external validity
  • confounding variables are not controlled (low)
• Baddeley (1956)


  Ppts were presented with semantically similar and dissimilar words. Tested immediately and then after a 20-minute delay. They found that the 20 min delay reduced their performance (prolonged rehearsal).
• Conclusion for encoding of LTM with semantic words


  This suggest that the LTM encodes semantically as the dissimilar words MERGE together, so its harder to remember
• Types of LTM

  • Semantic
  • Episodic
  • Procedural
• Semantic?

  “Concerns facts taken independent of context”

  • Objective facts, concepts and words
  • Requires effort
  • Declarative 
  • Not time-stamped
  • Rote learnt or learnt through experience 
• Episodic?

  “More personal memories such as associations of a particular place or time”

  • Events, places, people & emotions
  • Declarative 
  • Time stamped 
  • Learnt through personal experiences 
• Procedural?

  “Concerned with learning motor skills”

  • Skills and how to do things (muscle memory)
  • Automatic
  • Non-declarative
  • Practice & repetition 
  • Not time-stamped
• What does WMM stand for and who proposed it?


  Working model of memory proposed by Baddeley and Hitch (1974)
• Function of Central Executive 


  Slave driver and has overall control over the slave systems by monitoring info from coming in from different resources, decides what to pay attention to and allocates tasks to slave systems
• Function of Episodic Buffer


  Receives info from the CE and the other slave systems. It temporarily stores info allowing it to be manipulated or 'worked on'. Some studies have estimated the capacity at around 4 itwm. It can pass info back to the CE to the LTM
• Function of Phonological Store

  Deals with auditory info, the articulatory process allows maintenance rehearsal
• The Articulatory Control Process 


  Capacity of 2 sec and alternative for maintenance rehearsal in the MSMM
• Function of the Visuo-Spatial Sketchpad 


  The VSS stores visual info when required. Has two subsystems of the visual cache to store visual data.
• Evaluation of MSMM

  • Supporting research evidence
  • There is more than one type of STM
  • There is more than one type of rehearsal
• Evaluation of WMM

  • Clinical evidence
  • Dual task performance
  • Lack of clarity over the central executive
• Word length effect


  Monosyllabic and polysyllabic words. Average recall over several trials found that people remembered mono better than poly. This is because more complete words could be stored in the 2 seconds.
• Articulatory Suppressive task


  This is a verbal task used to distract the ppt when recalling information
• Dual-task performance

  1. The STM has separate visual and acoustic stores and they function independently.
  2. They both have unlimited capacity (empirical evidence)
  3. WMM has external validity
• What is interference?


  How info is lost from the LTM. It is when one memory prevents the retrieval of another memory and gets in the way.
• Retroactive interference 


  When new info interferes with an old memory
• Proactive interference 


  When old memory interferes with new info
• Memory involves the input, storage, and retrieval of information
• A model is a simplification that aids understanding
• Three types of memory:

  • Sensory memory
  • Short-term memory
  • Long-term memory
• The Multi-Store Model of Memory (MSMM) was proposed by Atkinson and Shiffrin in 1968
• Key features of the Multi-Store Model of Memory:

  • Three different types of memory stores: Sensory register, Short-term memory (STM), Long-term memory (LTM)
  • Linear model that operates in one direction
  • Each store retains different information for varying durations
• Functions of memory stores:

  • Capacity: the amount of information
  • Encoding: format/way information is stored
  • Duration: length of time information can be stored
• Sensory memory:

  • Encoding:
  • Iconic memory: visual
  • Echoic memory: sound
  • Haptic memory: touch
  • Olfactory memory: taste & smell
  • Capacity: High
  • Duration: ≤ 0.5 seconds