Lesson 2 - Coding, Capacity And Function Flashcards
What does ‘modality specific’ mean in regards to the Sensory Register?
It means that each sensory store (such as iconic for visual information) codes information differently
How did Baddeley investigate coding in STM?
He gave participants four lists of words to recall:
-List A contained words that sounded similar
-List B contained words that sounded dissimilar
-List C contained words with similar meanings
-List D had words with dissimilar meanings
What were Baddeley’s findings about STM?
He argued that STM is coded acoustically because when tested, participants performed worse with A than B, but C and D had no difference.
He theorised that because STM organises information according to how it sounds, similar sounding words can become muddled
How did Baddeley repeat his experiment to test the coding of LTM?
He tested participant recall after a delay of 20 minutes to ensure that the information had passed into LTM
What were Baddeley’s findings for the LTM experiment?
Recall of C is worse than of D, but there is no difference between A and B
He concluded that LTM is coded semantically
LTM organises information according to its meaning, so words with a different meaning can become confused
Pros and cons of Baddeley’s experiment
+ This study is a laboratory experiment and so it is easy to replicate as the variables have been closely controlled, meaning that reliability can be assessed
- The findings have low ecological validity as the information which the participants had to recall was artificial as was the laboratory setting, unlike in everyday life
What is the capacity of the Sensory Register?
Unlimited
What is the capacity of STM?
Miller found that the span of STM is 7 (+-) 2
If we try to recall more than the capacity, new incoming information displaces the old information
To help remember more, we can use chunking (grouping large amounts of information into smaller groups)
Pros and cons of the research on STM Capacity
+ Jacobs (1887) was the first person to acknowledge that STM capacity gradually improves with age
- This study was conducted a long time ago, so it may not have been done to the same scientific standards as today, which calls into question the validity of the findings
What is the capacity of LTM?
Unlimited
What is the duration of the sensory register?
250 milliseconds
How was the duration of STM tested and what is it?
Peterson & Peterson (1959) used nonsense trigram’s (random 3 consonants) to test STM duration.
To prevent participants keeping the information in STM using maintenance rehearsalthey 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
What are the pros and cons of the research done by Peterson and Peterson on the duration of STM?
+ 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 seen 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.
How was the duration of LTM tested and what is it?
In 1979, Bahrick 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.
Pros and cons of Bahrick’s research into duration of LTM?
+ This study has higher ecological validity than Peterson and Peterson, as the material used is more relevant and applicable to everyday life
- It is impossible to control extraneous variables, such as people staying in touch after leaving school or how many participants have looked in their yearbook since leaving school
