Coding, Capacity and Duration of Memory Flashcards
Define coding
Format in which information is stored in the memory stores
Define capacity
Amount of information that can be held in a memory store
Define duration
Length of time information can be held in memory
Define short-term memory
Limited-capacity memory store.
Coding: acoustic
Capacity: 5-9 items
Duration: 18-30 seconds
Define acoustic
Relating to sound
Define long-term memory
Permanent memory store.
Coding: Semantic
Capacity: Unlimited
Duration: Lifetime
Define semantic
Relating to meaning
What researcher conducted research into coding? Mention the year and how the experiment was conducted.
Baddeley 1966 Gave PPs lists of words to remember. Group 1: Acoustically similar Group 2: Acoustically dissimilar Group 3: Semantically similar Group 4: Semantically dissimilar
PPs were shown words and told to recall in the right order
What were the findings from Baddeley 1966 study on coding? What can be concluded from these findings about LTM?
When PPs had to recall words immediately after hearing them, they did worse on acoustically similar words.
When PPs had to recall words after 20 mins, they did worse on semantically similar words.
Conclusion: Info is coded semantically in LTM.
What researcher conducted the ‘Digit Span’ study on capacity? Mention the year and how the study was conducted. What were the findings of this study?
Jacobs 1887
Ask PP to recall 4 numbers in the correct order. Add 1 more number until the PP makes a mistake.
Findings:
Mean digit span for PPs was 9.3, whereas mean letter span was 7.3
What were the findings from Jacobs 1887 ‘Digit Span’ study on capacity?
Mean digit span for PPs was 9.3, whereas mean letter span was 7.3
What researcher studied ‘Span of memory and chunking’ in relation to capacity? What were his 2 observations? Mention the year and what his 2 conclusions were.
Miller 1956
Miller observed:
1. Every day practices; he found that things come in 7s - 7 days in a week, 7 deadly sins etc.
This suggested the capacity of STM is 7+/-2
2. People recall 5 letters as well as 5 numbers
They did this by chunking - grouping sets of digits/letters into units/chunks
Which researchers conducted a study on the ‘duration of STM’ on duration? Mention the year and how they carried out the study. Also mention why they did what they did in the study, and what their conclusions were.
Peterson + Peterson 1960
Study:
• Tested 24 undergrads
• Each stud given 8 trials. Each trial is 1 test.
• 1 test = stud given 3 letter consonant syllable and asked to count backwards from a 3 digit number until told to stop, to prevent mental rehearsal of the syllable
• On each trial, PPs counted backwards for diff. amount of time - 3 sec, 6 sec, 9 sec, 12 sec, 15 sec, 18 sec. This is known as the retention interval.
Findings:
% of correct responses negatively correlated w/ retention interval
Conclusion:
STM has a short duration unless we repeat something over and over.
Which researcher conducted a study on the ‘duration of LTM’ on duration? Mention the year and how the study was conducted.
What were the findings of this study?
What conclusion can be made from this study?
Bahrick 1975
Studied 400 PPs from Ohio aged 17-74
• Took high school yearbooks from PPs or schools
Recall tested in 2 ways:
1. Photo recognition test: Consisted of 50 photos, some from PPs yearbooks
2. Free recall test: PPs recalled all the names of their graduation class
Findings:
PPs tested within 15 years of graduation were 90% accurate in photo recognition
After 48 years, recall fell to 70%.
PPs tested within 15 years were were 60% accurate in free recall.
After 48 years, free recal fell to 30%
Conclusion: LTM lasts a long time.
Evaluate Baddeley’s study on coding.
Limitation: Artificial stimuli
• Baddeley used artificial stimuli vs meaningful material - word lists meant nothing to PPs
• Findings can’t be generalised to other memory tasks e.g. ppl may use semantic coding even for meaningful STM tasks
• So findings have limited application
