LS1 - Duration, Coding & Capacity Flashcards
Duration
How long a memory can be stored and how long it lasts.
STM Duration
Doesn’t last long and rehearsal is needed to keep the memory longer than a few seconds.
STM Duration Study
Peterson & Peterson - 24 undergrads presented with a consnant trigram and asked to count backwards in 3s to stop rehearsal after interveals between 0-18s, the trigram had to be repeated.
STM Duration Results
Peterson & Peterson - 90% of trigrams reherased after 3 seconds, 20% after 9 seconds and less than 10% at 18 seconds.
STM Duration Conclusion
Peterson & Peterson - Information decays quickly without being rehearsed, maximum duration of STM is 18 seconds.
STM Duration Strengths
Lab study, good control, easy to replicated.
STM Duration Weaknesses
Low Ecological Validity
Low Validity - Earlier trigrams may have interferred with remembering ones later down the line.
LTM Duration Study
Bahrick Et Al - Tested 400 American participants remembering classmates through pictures, matching names to pictures or recalling without picture cues.
LTM Duration Study Results
Bahrick Et Al - 48 years later when askd to link names and faces 70% accuracy but without pictures 30%
LTM Duration Study Conclusion
Bahrick Et Al - LTM can last a lifetime however memories can’t immediately be accessed, and recall is higher with cues.
LTM Duration Study Conclusion
Bahrick Et Al - LTM can last a lifetime however memories can’t immediately be accessed, and recall is higher with cues.
LTM Duration Study Strenghts
High Ecological Validity - It was a natural experiment and links to everyday life.
LTM Duration Study Weaknesses
Less Control Over Independant Variables e.g. people may have been kept in contact with certain classmates making results invalid.
Names and shit are meaningful so are likely to be rehearsed suggested not all LTM last a lifetime.
Capacity
How much information can be stored, LTM can be unlimited whilst STM is very limited.
STM Capacity Study
Jacobs - Researcher read out 4 digits and the participants were asked to repeat accurately, another digit was added until they could no longer accurately repeat the sequence.
STM Capacity Study Results
Jacobs - 9 digits and 7 letters was average. Capacity increased with age which could be because of expansion or strategies e.g. chunking.
STM Capacity Study Weaknesses
Lacks Ecological Validity - Remembering numbers isn’t realistic or meaningful
Order - Previous sequences may have confused with later ones, meaning validity would’ve been low.
Temporal Validity - Given it was done a while ago, so we don’t have EVs were controlled, however the study has since been repeated.
Miller (7+/-2)
After reviewing STM capacirty studies concluded 7 +/-2 items was the capacity ofe STM and processes like chunking can increase it.
Coding
How memory is stored i.e. acoustic, semantic and visual. Generally, STM is acoustic and LTM is semantic.
Coding Study
Baddeley - Pariticpants had to remember a list of Accoustically similar/dissimilar words and semantically dissimilar words.
Coding Study Results
Baddeley - When tested immediate;y, accoustically similar words were least accurate. When tested 20 minutes later, semnatically similar words were least accurate.
Coding Study Conclusions
Baddeley - STM is acoustically coded and LTM is semantically coded.
Coding Study Weaknesses
Low Ecological Validity - We’d never have to remember a meaningless list of words which suggests more meaningful situations may show different results.
