2 - Coding , Capacity and Duration Flashcards
What were the lists of words Baddeley used?
List A sounded similar
List B sounded dissimilar
List C had similar meanings
List D had dissimilar meanings
How is information coded into STM? How was this discovered?
Baddeley gave participants the four lists of words to recall.
He argued that it is coded acoustically because participants recalled list B better than list A, and there was no difference between list C and D.
He theorised that because it is acoustically coded, similar sounding words can become muddled.
How is information coded into LTM? How was this discovered?
Baddeley tested the participants recall of the lists after a 20 minute delay in order to make sure it had passed into LTM.
Participants recalled list D better than list C and there was no difference in list A and B.
He concluded that it is coded semantically.
How was the capacity of short term memory discovered?
The digit span test.
Participants were given several sequences of digits or letters, asking them to repeat the sequence in the right order immediately after he had given it.
The sequences got longer by one item each time.
What were the results of the digit span test? What is the capacity of STM?
It was found that we cab hold on average 9.3 digits and 7.3 letters.
Miller reviewed psychological research age concluded that the span of STM is 7 (+/-) 2.
If we try and recall more information than we have capacity for, then new information displaces old information.
What is chunking?
Grouping large amounts of information into smaller groups. This can help us remember more.
How was the duration of STM discovered?
Nonsense trigrams ( random 3 consonants ) were used.
To prevent participants keeping the information in STM using rehearsal they were asked to count backwards from 100 in threes.
After 3 seconds recall was accurate 90% of the time, after 9 seconds they were accurate 20% of the time, but after 18 seconds it was accurate only 2% of the time.
What was the conclusion of the nonsense trigram test?
Information in STM lasts for less than 18-30 seconds without rehearsal, before it is lost due to decay.
What is the evidence of duration of LTM?
400 people of various ages (17-74) were tested on their memory of their classmates.
A photo recognition test consisted of participants being shown 50 photos and deciding if they belonged to their class or not. In a free recall test, participants were asked to list the names they could remember from their graduating class.
What were the results of the LTM duration test? What conclusion was reached?
There was 90% accuracy at identifying faces of school friends within 15 years of leaving school.
After 48 years, this declined to 70%.
Free recall of names of class makers was 60% accurate within 15 years of leaving school.
After 48 years this dropped to 30%.
The conclusion was that the duration of LTM is potentially a lifetime but sometimes we have retrieval failure and need retrieval cues in order to access this information.
