Coding capacity and duration

• What is coding in the context of memory stores?


  The format in which information is stored in various memory stores
• What does capacity refer to in memory stores?


  The amount of memory that can be held in a memory store
• What does duration refer to in memory stores?


  The length of time we can hold information for
• What is the sensory register?


  The first immediate form of memory that takes in sensory information through our five senses
• What are the five senses involved in the sensory register?


  Sight, smell, hearing, taste, and touch
• What is Short Term Memory (STM)?


  The limited time-capacity store that holds information for a short duration
• What is the typical duration of information in Short Term Memory (STM)?


  About 18 seconds
• What is the average capacity of Short Term Memory (STM)?


  Between 5-9 items
• What is Long Term Memory (LTM)?


  The permanent memory store that can hold information for a lifetime
• What type of coding is usually used in Long Term Memory (LTM)?


  Semantic coding (words and meanings)
• What is the capacity of Long Term Memory (LTM)?


  Unlimited capacity
• How long can Long Term Memory (LTM) store memories?


  For a lifetime
• What are the key characteristics of the three types of memory stores?

  • Sensory Register:
  • Immediate memory
  • Takes in sensory information
  • Involves five senses
  • Short Term Memory (STM):
  • Limited duration (about 18 seconds)
  • Limited capacity (5-9 items)
  • Acoustic coding
  • Long Term Memory (LTM):
  • Permanent storage
  • Unlimited capacity
  • Semantic coding
• Baddeley (1966) gave participants a list of words to four group of participants to remember. • Were given acoustically similar words (e.g cat, cab, can, mat) • Were given acoustically dissimilar words (e.g pit, few, cow, rag) • Were given semantically similar words (e.g great, large, big) • Were given semantically dissimilar words (.e good, huge, hot)
• Method Participants were shown the original words & asked to recall them in the correct order. •They were asked to recall the list immediately, testing the coding of short-term memory (STM) or after 20 minutes, testing the coding of long-term memory (LTM)
• Conclusions: • STM relies heavily on acoustic coding (dissimilar) • LTM primarily makes use of semantic coding (dissimilar)
• Digit Span Test


  A test to measure an individual's ability to process and store information (coding capacity) by recalling a sequence of digits.
• Jacob's Digit Span Test


  A method to measure coding capacity by asking participants to recall a sequence of digits or letters in the correct order.
• Short-Term Memory


  A type of memory where information is held for a brief period of time, typically seconds to a minute, before being either rehearsed or forgotten.
• Coding Capacity


  The ability to process and store information in short-term memory.
• Research on Capacity: Jacob (1887) The Digit Span Test determines the individuals digit span. For example, the researcher gives a number of digits and participant has to recall them in the correct order. The researcher then increases the amount by 1 digit and the participant has to recall again until they cannot recall the order correctly. Jacob found that the mean span for digits across all participants was 9.3 items. For letters it was slightly lower at 7.3 letters.
• Who conducted research on the capacity of short-term memory (STM) in 1956?

  Miller
• What did Miller argue about the number of items that can be held in STM?


  That the capacity is 7 items, plus or minus 2
• What are some examples Miller provided to support his argument about the number 7?


  7 notes on a musical scale, 7 days of the week, 7 deadly sins
• How can people increase the capacity of their STM according to Miller?


  By 'chunking' information together
• How might someone remember the area code of a phone number using Miller's concept?


  By chunking the digits into smaller groups
• What limitation did Miller's research have regarding control?


  It lacked adequate control, leading to potential confounding variables
• What confounding variable might have affected the digit spans in Miller's study?


  Distractions experienced by participants
• What did Nelson Cowan conclude about the capacity of STM in 2001?


  That the capacity is about 4 plus or minus 1 chunks
• How does Cowan's estimate of STM capacity compare to Miller's estimate?


  Cowan's estimate of 4 chunks is lower than Miller's estimate of 5 chunks
• What are the key findings of Miller's research on STM capacity?


  • STM capacity is 7 items, plus or minus 2
  • People can increase capacity by chunking information
  • Examples include 7 notes, 7 days, and 7 sins
• What are the limitations of Miller's research on STM capacity?


  • Lack of adequate control in experiments
  • Potential confounding variables like distractions
  • Cowan's review suggests a lower capacity estimate of 4 plus or minus 1 chunks
• What was the aim of Peterson & Peterson's (1959) research on duration in short-term memory (STM)?


  To investigate how different short intervals containing an interference task affect recall.
• What method did Peterson & Peterson use in their study?


  • Participants were given trigrams (e.g., JBW, PDX) to remember.
  • Participants received a 3-digit number (e.g., 360, 294).
  • They spelled out the syllable and counted backwards from the number.
  • They were told to stop after varying periods: 3, 6, 9, 12, 15, or 18 seconds.
• Why did participants count backwards from a 3-digit number in the study?


  To prevent repetition of the trigram by the participant.
• What were the varying time intervals used in the Peterson & Peterson study?


  3, 6, 9, 12, 15, or 18 seconds.
• What were the findings of Peterson & Peterson's research regarding recall accuracy?


  • Longer intervals resulted in less accurate recall.
  • 3 seconds = 80% recall.
  • 18 seconds = about 3% recall.
• What conclusion did Peterson & Peterson draw about the duration of STM?


  The duration of STM is not much longer than 18 seconds.
• What were some limitations of Peterson & Peterson's study?


  • Lack of external validity.
  • Artificial stimulus material.
  • Recalling syllables does not reflect everyday memory activities.
  • Use of an artificial laboratory setting.
• What alternative explanation did Peterson & Peterson suggest for their findings?


  The findings may be more related to interference than duration.