Memory- Coding, capacity & duration of memory Flashcards
Coding -
The format in which information is stored in the various memory stores.
Capacity -
The amount of information that can be held in a memory store.
Duration -
The length of time information can be held in memory.
Short-term memory (STM) -
The limited-capacity memory store. Coding is mainly acoustic (sounds), capacity is between 5 and 9 items on average, duration is between about 18 and 30 seconds.
Long-term memory (LTM) -
The permanent memory store. Coding is mainly semantic (meaning), it has unlimited capacity and can store memories for up to a lifetime.
What is the process of converting information from one form to another called?
Coding.
What did Alan Baddeley (1966a, 1966b) study in his research on coding?
He studied how information is stored in different formats depending on the memory store by giving participants lists of words to remember.
What were the four groups of participants in Baddeley’s study, and what type of words did they receive?
Group 1: acoustically similar words (e.g., cat, cab, can).
Group 2: acoustically dissimilar words (e.g., pit, few, cow).
Group 3: semantically similar words (e.g., great, large, big).
Group 4: semantically dissimilar words (e.g., good, huge, hot).
What did Baddeley find about STM recall with acoustically similar words?
Participants tended to do worse with acoustically similar words in STM recall.
What did Baddeley find about LTM recall with semantically similar words?
Participants did worse with semantically similar words in LTM recall, suggesting information is coded semantically in LTM.
What is digit span, and how did Joseph Jacobs (1887) measure it?
Digit span is the amount of information STM can hold at one time. Jacobs measured it by reading out digits and asking participants to recall them in order, increasing the number of digits until recall failed.
What was the mean digit span and letter span found by Jacobs?
Mean digit span: 9.3 items. Mean letter span: 7.3 items.
What did George Miller (1956) observe about the capacity of STM?
He observed that the span of STM is about 7 items (plus or minus 2) and noted that people use chunking to group information into units.
What is chunking, and how does it affect memory?
Chunking is grouping sets of digits or letters into units, allowing people to recall more information, such as recalling 5 words as easily as 5 letters.
What did Cowan (2001) conclude about the capacity of STM?
Cowan concluded that the capacity of STM is only about 4 chunks, suggesting Miller may have overestimated it.
What is the duration of STM, and how did Peterson and Peterson (1959) study it?
Duration is how long STM lasts. Peterson and Peterson tested it by having participants remember consonant syllables while counting backwards to prevent rehearsal.
What were the retention intervals used in Peterson and Peterson’s study?
3, 6, 9, 12, 15, or 18 seconds.
What did Peterson and Peterson find about the duration of STM?
STM has a very short duration unless information is rehearsed repeatedly.
What did Bahrick et al. (1975) study about LTM duration?
They studied the duration of LTM by testing participants’ recall of high school classmates using photo recognition and free recall tests.
What were the results of Bahrick et al.’s study on photo recognition and free recall?
Photo recognition: 90% accurate within 15 years, dropping to 70% after 48 years. Free recall: 60% accurate within 15 years, dropping to 30% after 48 years.
What is one limitation of Baddeley’s study on coding?
It used artificial stimuli (word lists with no personal meaning), limiting generalizability to real-life memory tasks.
What is one limitation of Jacobs’s study on digit span?
It lacked adequate control, as participants may have been distracted, potentially affecting the validity of the results.
What is one limitation of Miller’s research on chunking?
He may have overestimated STM capacity, as Cowan (2001) suggested it is only about 4 chunks.
What is one limitation of Peterson and Peterson’s study on STM duration?
The use of meaningless consonant syllables lacks external validity, as it doesn’t reflect most real-life memory activities.
What is one strength of Bahrick et al.’s study on LTM duration?
It has high external validity because it studied real-life meaningful memories.
What is one downside of Bahrick et al.’s study?
Confounding variables, such as participants rehearsing memories by looking at yearbooks, were not controlled.
What are two explanations for forgetting in STM?
Spontaneous decay (memory trace disappears) and displacement (new information pushes out old information due to limited capacity).
How might counting backwards in Peterson and Peterson’s study cause displacement?
Counting backwards could introduce new information, displacing the consonant syllables in STM.
How might Peterson and Peterson’s study lack internal validity?
The counting task may have caused displacement, making it unclear whether forgetting was due to decay or displacement.
