Coding, Capacity And Duration Flashcards
What is coding?
the process of converting information from one form to another
Coding refers to how information is stored in different memory systems.
What was the procedure of Badddeley’s research in coding?
Gave different lists of words to 4 groups to remember
- participants shown original words
- asked to recall them in the correct order
What were the findings of Baddeley’s research in coding?
- Having to recall immediately after hearing it (STM recall) = tended to do worse with acoustically similar words
- Having to recall them after 20 mins (LTM recall) = tended to worse with semantically similar words
What were the groups in baddeley’s research in coding?
Group 1: words sounded similar
Group 2: words sounded different
Group 3: words with similar meaning
Group 4: words with different meaning
What does Baddeley’s research suggest about coding in short-term memory (STM) and long-term memory (LTM)?
STM codes acoustically; LTM codes semantically
What is the average capacity of short-term memory?
Between 5 - 9 items
This range is often referred to as Miller’s law.
What is the duration of short-term memory?
About 18 seconds
This duration can be extended through techniques like verbal rehearsal.
What is the main coding method used in long-term memory?
Semantic coding
Semantic coding involves processing the meaning of information.
What is the capacity and duration of LTM?
Unlimited capacity and can store memories for up to a lifetimes
Who looked into capacity?
Jacobs and Miller
Jacobs developed a technique to measure digit span
- researcher gave 4 digits and participants asked to recall them correctly
- if theyre correct, number of digits increased until they fail to recall
What was the mean digit span found by Jacobs in his research?
9.3 items
Jacobs also found a mean letter span of 7.3 items.
According to Miller, what is the typical span of short-term memory?
About 7 items (+/- 2)
Miller observed that many things in life come in 7s, influencing his estimate.
What technique can help increase memory span by grouping information?
Chunking
Chunking involves breaking down information into manageable units.
noted people can recall 5 words and 5 letters
Who looked in duration?
Peterson and Peterson and Bahrick et al
What was Peterson and Peterson’s research in duration?
Tested 24 undergrad students
- each student took part in 8 trials
- A trial/test
- on each trial, students given an consonant syllable to remember and a 3 digit number
- asked to count backwards from the 3 digit number until told to stop
What else is there to note about Peterson and Peterson’s procedure in duration?
Counting backwards: prevents any mental rehearsal of the consonant syllable
- each trial asked to stop after a certain amount of time called the retention interval
Asked to stop in 3s
EG: 3,6,9,12 seconds etc.
What did Peterson and Peterson’s study reveal about the duration of short-term memory?
Very short duration unless rehearsed
Their study used consonant syllables and a retention interval to test memory duration.
What was the procedure of Bahrick et al’s research?
Studied 392 participants from Ohio
- All ages between 17 and 74
- Obtained high school yearbooks to test recall through photo recognition (PR) and free recall (FR)
PR: involves 50 photos, some from their yearbooks
FR: participants asked to recall all of the names of their class
What was the finding of Bahrick et al. regarding long-term memory recall?
- 15 yrs after graduation: about 90% in PR and about 60% accuracy in FR
- 48 yrs after graduation: 70% in PR and 30% in FR
Their study showed that LTM can last a very long time.
What are the limitations of coding?
Specifically Baddeley’s study
Artificial stimuli; findings not generalizable to different kinds of memory tasks
The words used lacked personal meaning for participants
- Processing meaningful info = people may use semantic coding even for STM tasks
What else is there to add onto limitations of baddeley’s coding study?
Shephard found recalling meaningless pictures meant a lower recall rate
findings have limited application
What are limitations of capacity?
Specifically Jacobs and Miller’s study?
Jacobs:
- study conducted a long time ago
- Early research lacked adequate control
- Paticipants may have been distracted while being tested
- Means results may not be valid
- Confounding variables (distraction) not controlled
Miller:
- may of overestimated the capacity of STM
What did Cowan’s review suggest about the capacity of short-term memory?
As proof for the limitations of capacity
About 4 chunks
Cowan’s findings suggest a lower end of Miller’s original estimate.
What are the limitations of duration?
Specifically Peterson and Peterson’s study and bahrick et al
Peterson and Peterson:
- Artifical stimulus material
- Memorising consonant syllabes doesnt reflect real life memory activities
- Lacks external validity
Bahrick et al:
- didnt control confounding variables such as participants looking at their yearbook regularly = memorise photos
What was a strength of Bahrick et al.’s study?
High external validity
focused on meaningful memories giving higher recall rates and reflecting a more ‘real’ estimate of the duration of LTM
