CODING, CAPACITY, DURATION

• CODING?

  format in which information is stored in memory
• CAPACITY?

  amount of information that can be held in memory
• DURATION?

  length of time information can be held in memory
• WHAT ARE THE TYPES OF MEMORY STORE?

  • sensory register
  • short term memory
  • long term memory
• WHAT IS THE CODING OF SENSORY REGISTER?

  modality specific (dependent on senses)
• WHAT IS THE CODING OF SHORT TERM MEMORY?

  mainly acoustic
• WHAT IS THE CODING OF LONG TERM MEMORY?

  mainly semantic
• WHAT IS THE CAPACITY OF SENSORY REGISTER?

  unlimited
• WHAT IS THE CAPACITY OF SHORT TERM MEMORY?

  7 +/- 2
• WHAT IS THE CAPACITY OF LONG TERM MEMORY?

  unlimited
• WHAT IS THE DURATION OF SENSORY REGISTER?

  250 ms - 4 s
• WHAT IS THE DURATION OF SHORT TERM MEMORY?

  18 - 30 s
• WHAT IS THE DURATION OF LONG TERM MEMORY?

  potentially forever
• WHO DID RESEARCH ON CODING?

  Baddeley
• WHO DID RESEARCH ON CAPACITY?

  Miller
• WHO DID RESEARCH ON DURATION (STM)?

  Peterson and Peterson
• WHO DID RESEARCH ON DURATION (LTM)?

  Bahrick et al
• WHAT DID BADDELELY DISCOVER?

  STM coded acoustically, LTM coded semantically
• HOW DID BADDELEY RESEARCH CODING?

  1. Different lists of words given to different groups of participants
  2. First list was acoustically similar, other acoustically dissimilar
  3. Tested STM by getting patients to immediately recall list (less words recalled if acoustically similar)
  4. When tested after 20 minute delay, different effect
  5. Third list was semantically similar, other semantically dissimilar
  6. Tested LTM by getting patients to recall list after 20 minutes (less words recalled if semantically similar)
  7. When tested immediately after hearing list, different effect
• WHAT DID MILLER DISCOVER?

  on average, people can remember 7 +/- 2 items in their STM
• WHOS TECHNIQUE OF MEASURING DIGIT SPAN DID MILLER USE?

  Jacob's
• HOW IS DIGIT SPAN MEASURED?

  1. Researcher reads out string of digits
  2. Participant asked to recall in correct order out loud
  3. If participant is correct, researcher reads out new string of digits with one digit added
  4. Repeated until participant cannot recall order correctly
• WHAT ELSE DID MILLER DISCOVER?

  people chunk items together to help improve their memory
• WHAT DID PETERSON AND PETERSON DISCOVER?

  on average, duration of STM is 18 - 30 s
• HOW DID PETERSON AND PETERSON CARRY OUT THEIR RESEARCH?

  1. Had 24 students
  2. Showed each of them a trigram to remember
  3. Gave them a three digit number to count back from after seeing trigram (prevent rehearsal)
  4. Repeated multiple times
  5. Stopped participant at different intervals
  6. Found the longest time items could be held was 18 - 30 s
• WHAT DID BAHRICK ET AL DISCOVER?

  duration of LTM is potentially forever
• HOW DID BAHRICK ET AL CARRY OUT HIS RESEARCH?

  1. 392 Americans aged 17 to 74
  2. Asked to recall names of people in high school yearbook
  3. People who graduated within past 15 years recalled 90% of names while looking at photos
  4. People who graduated around 50 years ago recalled 74% of names while looking at photos
  5. Suggests LTM can last a very long time
  6. Free recall version was 60% and 30% respectively
• WHAT EVALUATION POINTS SHOULD BE USED FOR BADDELEY?

  application and validity
• WHAT EVALUATION POINTS SHOULD BE USED FOR MILLER?

  application and reliability
• WHAT EVALUATION POINTS SHOULD BE USED FOR PETERSON AND PETERSON?

  validity
• WHAT EVALUATION POINTS SHOULD BE USED FOR BAHRICK?

  validity
• APPLICATION OF BADDELEY'S RESEARCH?

  • limited application
  • artificial task
  • but findings could be useful for understanding problems for people with learning difficulties/ amnesia
• VALIDITY OF BADDELEY'S RESEARCH?

  • memorising lists lacks mundane realism
  • results lack ecological validity
  • do not reflect everyday memory
• APPLIICATION OF MILLER'S RESEARCH?

  • capacity depends on lots of things
  • not useful as a general law
• RELIABILITY OF MILLER'S RESEARCH?

  • repeated findings in lots of studies
  • support Miller's law as reliable measure of STM capacity
  • other argue no 'magic number' for memory capacity
• VALIDITY OF PETERSON AND PETERSON'S RESEARCH?

  • artificial stimuli
  • lacks mundane realism
  • results lack ecological validity
  • cannot be generalised to real memory events
  • however, study still valid in certain instances (postcodes)
• VALIDITY OF BAHRICK'S RESEARCH?

  • high mundane realism
  • as real pictures of people used
  • results have high ecological validity
  • however realistic
  • so hard to control extraneous variables
  • lacks internal validity