Lesson 2 Flashcards
What is the coding of sensory registry ?
The coding is modality specific, meaning that each sensory store codes information differently
How is STM coded
STM is coded acoustically and organises information based on how it actually sounds, which is why similar sounding material can be muddled. Baddeley gave participants 4 lists of words to recall. List A had similar sounding words, B had dissimilar sounding words, C had similar meaning words and D had dissimilar meaning words. A was recalled worse than B and there was no difference between D and C
How is LTM coded?
It is coded semantically - organising information according to its meaning so similar meanings become confused
Baddeley repeated the experiment but asked for recall after a 20 min delay to ensure the information had been passed to the LTM. Recall of C was worse than D and there was no difference in A and B.
Evaluation for studies into coding
+ Lab experiments, so easy to replicate as variables have been closely controlled. Also means that reliability can be assessed
-Findingd have low ecological validity. The list of information the participants needed to recall was artificial as was th lab setting
What is the capacity for the Sensory register
It is unlimited
What is the capacity for the STM
Jacobs did digit span test, getting participants to recall a list of digits straight away in the correct order with a digit added to the end every time. He found we could hold around 7.3-9.3 digits on average and miller concluded that STM has a capacity of 7+/-2 pieces of information. Recalling more information than this limit would cause old info to be displaced.
Also found that people could recall 5 letters as easily as words, so Chungking can help us remember more
Evaluation of STM capacity?
+jacobs research was the first to acknowledge that STM capacity improves with age
-Study conducted long ago and may not have been done to the same scientific and rigorous standard, therefore the validity of the findings can be questioned
What is the capacity of the LTM?
The capacity is potentially unlimited
What is the duration of the SR?
250ms
Shia the duration of the STM
18-30s before the information is lost to decay
What is duration of LTM?
Potentially a lifetime but sometimes we have retrieval failure and need retrieval cues to access it
Research into duration STM
Peterson & Peterson (1959) used nonsense trigram’s (random 3 consonants) to test STM duration. To prevent participants keeping the information in STM using maintenance 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 only accurate 2% of the time. They concluded that information in STM lasts for 18-30 seconds without rehearsal, before it is lost due to decay.
Evaluation Peterson and Peterson STM duration
In this study, the researchers used fixed timings for participants to count backwards from. They also eliminated noise and other factors that could have had an influence on memory. The research can therefore be said to have a high level of control, using standardised procedures to make sure all participants experienced the same process.
- The findings of this study may have been caused by interference rather than by STM having a short duration. It is possible that earlier learnt trigrams became confused with later ones.
Research into duration LTM
Bahrick (1979) tested 400 people of various ages (17-74) on their memory of their classmates. A photo recognition test consisted of participants being shown 50 photos and deciding if they belonged to their classmates or not. In a free recall test participants were asked to list the names they could remember from their graduating class. They found 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 classmates was 60% accurate within 15 years of leaving school, dropping to 30% after 48 years. Bahrick et al. (1979) concluded 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.
Evaluation duration of LTM
- This study has higher ecological validity than Peterson and Peterson (1959) as the material used was more meaningful and relevant to everyday life.
- It is problematic to control for extraneous variables, such as people staying in touch after they left school or how many participants have looked in their yearbook since leaving school.
