Memory - Coding, Duration, Capacity Flashcards
What is Capacity?
The amount of information that can be held in a memory store
What is duration?
The length of time information can be held in memory
What are the 3 types of memory?
Sensory
Short term
Long term
What is the capacity of LTM & how do losses occur?
Considered limitless
Losses happen due to decay & interference
What is the capacity of the STM?
Limited - can hold a small amount of information before it’s forgotten
What is the experiment demonstrated by Jacobs that tests the capacity of STM?
Serial digit span study
What was the procedure of the serial digit span study?
Participants were given a long list of numbers and told to repeat them
TBC
What did Jacobs conclude from the serial digit span study?
Showed the average recall & capacity of STM was 7 digits
What did Miller say about the capacity of STM?
Suggests we can gold 5-9 (plus/minus 2) objects in STM
What is displacement in memory?
When the STM is full so new information that is received pushes out the old information & takes it’s place so it is forgotten
How can the capacity of STM be improved?
Chunking - grouping information together
E.g. 1984 instead of 1.9.8.4
What is the duration of STM?
Doesn’t last very long
Rehearsal keep the memory active
Verbal rehearsal can allow the memory to become long term
What was the study performed by Peterson & Peterson on the duration of STM?
24 Participants had a trigram & were given a number & had to count back from it in 3s for intervals of 3,6,9,12,15 or 18 seconds until they saw a red light appear then they recalled the trigram
What did Peterson & Peterson find from their study?
After 3 secs - 80% trigrams recalled correctly
6 secs- 50%
18 secs - 10%
What did Peterson & Peterson conclude from their study?
STM is limited to a duration of 18 seconds when rehearsal was prevented
What are the strengths of Jacobs study?
Controlled lab environment - good control of EVs
Evidence still used today even though quite old
What are the limitations of Jacobs study?
Controlled lab study - artificial environment
Lacks ecological validity - not generalisable to real life
Demand characteristics
Lacks temporal validity - study done 150 years ago
What are the strengths of Peterson & Peterson’s study?
real life application -> remembering phone numbers
What are the limitations of Peterson & Peterson’s study?
meaningless stimuli - lacking external validity
What is the duration of the LTM?
A lifetime
What was the procedure for Bahrick’s study on the duration of LTM?
Had 392 participants ages 17-74 from Ohio, recall people from their high school yearbooks using photo recognition & free recall
What were the findings for the photo recognition?
15 yrs after graduation - 90% accurate
48 yrs after graduation - 70% accurate
What were the findings for free recall?
15yrs after graduation - 60%
48yrs after graduation - 30%
What was the conclusion from Bahrick’s study?
The LTM lasts a long time
