Memory: Coding, capacity, and duration (AO1) Flashcards
(19 cards)
What is meant by coding?
The format in which sensory information is modified and stored in the brain. The most common forms of encoding are visual, acoustic, and semantic.
What is meant by capacity?
The amount of information that can be stored in memory.
What is meant by duration?
The length of time that information can be stored in memory.
What are the three types of memory?
Sensory store, short-term memory, and long-term memory.
What is the coding, capacity, and duration of the sensory store?
Coding - modality specific
Capacity - unknown, but very large
Duration - approximately 250ms
What is the coding, capacity, and duration of short-term memory?
Coding - acoustic
Capacity - 7 +/- 2 chunks of information
Duration - 18-30 seconds
What is the coding, capacity, and duration of long-term memory?
Coding - semantic
Capacity - unlimited
Duration - a lifetime
How is the capacity of STM often measured?
Using a digit span task.
Who researched STM capacity, and what did they find?
Jacobs (1887): Average digit span for numbers is 9.3, average digit span for letters is 7.3.
Miller (1956): The magic number is 7 +/- 2. People are good at remembering 5-9 items (7 dots, 7 letters, 7 musical notes).
How can we increase STM capacity?
Miller argued that we can increase our STM capacity by chunking information together into meaningful units. If we find links between things and group them together, we are more likely to remember them.
Who researched STM duration?
Peterson and Peterson (1959).
Describe the procedure of Peterson and Peterson (1959).
On each of the 8 trials, participants were given a consonant trigram and a three-digit number. They were then asked to recall the trigram after intervals of 3, 6, 9, 12, 15, or 18 seconds. To prevent rehearsal, participants were asked to count backwards from their three-digit number.
What were the findings and conclusion of Peterson and Peterson (1959)?
After 3 seconds, 80% of participants successfully recalled the trigram. However, after 9 seconds, this figure dropped to 20%, and after 18 seconds, less than 10% were able to successfully recall the trigram.
The duration of STM is less than 18 seconds.
Who researched LTM duration?
Bahrick et al. (1975).
Describe the procedure of Bahrick et al. (1975).
Participants were asked to either recall the names of students from 50 photos in their high school yearbook (photo recognition) or list all the names they could remember from their graduating class (free recall).
What were the findings and conclusion of Bahrick et al. (1975)?
Photo recognition:
Participants tested within 15 years of graduation were 90% accurate. When tested over 48 years after graduation, recall decreased to 70%.
Free recall:
Within 15 years, participants were 60% accurate. Over 48 years after graduation, participants were 30% accurate.
This suggests that LTM duration can last a very long time.
Who researched encoding of STM and LTM?
Baddeley (1966).
Describe the procedure of Baddeley (1966).
Participants were shown a list of acoustically/semantically similar/dissimilar words, and were asked to recall them in the correct order either immediately (STM) or after 20 minutes (LTM).
What were the findings and conclusion of Baddeley (1966)?
Participants had difficulty recalling acoustically similar words when tested immediately (STM), but not when recalling after 20 minutes (LTM).
Participants had difficulty recalling semantically similar words when tested after 20 minutes (LTM), but not when recalling immediately (STM).
This suggests that information is encoded acoustically in STM and semantically in LTM.
