Coding Capacity and Duration of Memory Flashcards
Define coding
The format in which information is stored in various memory stores
Define capacity
The amount of information that can be held in a memory store
Define Duration
The length of time information can be held in memory
Short term memory (STM)
Definition,Coding capcity and duration
-The limited capacity memory store.
-Coding is mainly acoustic (sounds),
-Capacity is between 5-9 items
-Duration is between 18 and 30 seconds
Define Long Term Memory (LTM)
-Known as the permanent memory store.
-Coding is mainly semantic (meaning)
-It has unlimited capacity
-Stores memories for up to a lifetime
Define chunking
When large pieces of information is divided into smaller chunks that are easier to retain in short-term memory
Procedure of Baddeleys research on coding
This study proves that information is coded semantically in LTM
*Baddeley (1966)-Gave different lists of words to four groups of participants to remember
What were the 4 groups of particpants Alan Baddeley used
Group 1- Acoustically similar -words sound similar-
Group 2- Acoustically dissimilar
Group 3- Semantically similar -words with similar meanings-
Group 4- Semantically dissimilar
only one of those groups needs mentioning in a 16 marker
Findings of Alan Baddeley (1966) research on coding (5)
*Ppts were then shown the original words and asked to recall them in the correct order
*When they were asking to recall it after hearing the words (STM recall), they tended to do worse with acoustically similar words
-Suggesting that information is coded acoustically in STM
*If participants were asked to recall the words after a time interval of 20 mins (LTM recall), They did worse with the semantically similar words.
*This suggests information is coded semantically in LTM
Research on capacity- Joseph Jacobs (1887)Procedure (3)
*He developed a technique to measure digit span.
*The researcher gives for example, 4 digits and then the participant is asked to recall these in the correct order out loud.
*If this is correct the researcher reads out 5 digits and so on until the participant cannot recall the order correctly.
Findings of Joseph Jacobs (1887)
-The mean span for digits across all ppts was 9.3 items
-The mean span for letters was 7.3
Research on capacity- Span of memory and chunking- (5)
The guy obsessed with 7s
-George Miller (1956)
*He made observations of everyday practice.
-For example he noted that things come in sevens: there are 7 notes on the musical scale, 7 days of the week, 7 deadly sins and so on.
*This suggests that the span (or capacity) of STM is about 7 items (plus or minus 2).
*Miller also noticed that people can recall 5 words as well as 5 letters and they do this by chunking-
Research on Duration-Duration of STM (8)
Shows that the duration of STM is short
- Peterson & Peterson (1959)
- Tested 24 students.
- Each student took part in 8 trials.
- On each trial a student was given a consonant syllable (also known as trigram, such as YCG) to remember and was also given a 3 digit number.
- The student was then asked to count backwards from that 3 digit number until told to stop.
- The counting backwards was to prevent any mental rehearsal.
- On each trial they were told to stop after a different amount of time -3, 6, 9 seconds-
- Their findings suggest that STM may have a very short duration unless it is repeated over and over again
Research on Duration-Duration of LTM (6)
- Bahrick (1975)
- He Studied 392 ppts aged 17-74.
- High school yearbooks were obtained from the ppts or directly from some schools.
- Recall was tested through photo-recognition tests which consisted of 50 photos from their high school yearbook.
- Ppts who were tested within 15 years of graduation were about 90% accurate in photo recognition.
- After 48 years, recall declined to about 70% for photo recognition.
This shows that LTM can last a very long time
