Coding, Capacity And Duration Flashcards
(30 cards)
What is coding?
The process of converting information from one format to another is called coding.
What are the 3 types of encoding?
-visual (as an image)
-acoustic (as a sound)
-semantic (through its meaning)
What was Baddeley 1966 aim?
Investigated coding used in STM and LTM. He predicted STM would show preference for acoustic and LTM should prefer semantic.
What was Baddeley 1966 method?
Fours groups of ppts were each shown a different list of words to memorise:
-Group 1 were given acoustically similar words
-Group 2 were given acoustically dissimilar words
-Group 3 were given semantically similar words
-Group 4 were given semantically dissimilar words
Ppts were then asked to recall them in the correct order. Some participants were asked to recall them immediately afterwards (to establish coding in STM) whilst others were asked to recall them 20 minutes after (to test coding in LTM)
What were Baddeley 1966 results?
When asked to recall immediately, ppts did worse (i.e. recall fewer words ion the correct order) with acoustically similar words.
When ppts were asked to recall 20 mins after, they did worse with the semantically similar words.
What was Baddeley 1966 conclusion?
Information is coded acoustically in STM and semantically in the LTM.
How can Baddeley’s results be used to support the conclusion for STM and LTM?
STM- when words sound the same we remember the sound not the word so we get confused between words that sound similar. When words sound different it is easier to remember. This suggests STM encodes acoustically.
LTM- when words mean the same thing we remember the general meaning not individual words so we get confused when they mean similar things. When they have different meanings it’s easier to remember them. Suggesting LTM encodes semantically.
What are sensory registers (SR)?
A short duration store holding impressions of information received by the 5 senses.
What is the short term memory (STM)?
Limited capacity memory store. Coding is mainly acoustic, capacity is 7 +/- 2 items on average. Duration is between 18 and 30 seconds.
What is the 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 capacity?
Capacity is a measurement of how much information a memory store can hold. One way of measuring the capacity of STM is using the digit span task (Jacobs, 1887)
What is the digit span?
The research researcher gives participants a list of digits (numbers from zero through nine) and then the participant is asked to recall these in the correct order. If they are correct, the researcher gives the participant another list but with one more digit than the last one and asks them to recall in the correct order. The researcher continues to add one digit to each proceeding list until the participant cannot recall the order correctly. This determines the individuals digit span. Jacobs found that the mean span for digits across all participants was 9.3 items. When repeated with letters rather than digit, Jacob’s found the mean span for letters was 7.3.
Describe span of memory and chunking?
From Jacob’s research, Miller (1956) proposed that the span (or capacity) of STM is around seven items (plus or -2). This was reinforced by everyday observations, where Miller noted that things tend to come in sevens such as seven notes on the musical scale, seven days of the week, seven deadly sins etc.
Miller also noted that people can recall five words as well as they can recall five letters and identified chunking as a process they used.
What is chunking (Miller, 1956)?
Drinking is where we group together sets of digits or letters into units or chunks.
What is duration?
Duration is a measurement of how long a memory store can hold information for.
Who investigated the duration of short-term memory and what was their aim?
Peterson and Peterson, 1959. The aim was to investigate the duration of the short-term memory.
What was Peterson and Peterson’s method?
Tested 24 undergrad students who took part in a trial. On each trial they were given a trigram (three letter letters that don’t make a word- they don’t have a meaning) to remember and was also given a three digit number. They had to countdown from the number until they were told to stop to prevent mental rehearsal of the trigram. On each trial, they varied how long they told the participants to count back from- 3, 6, 9, 12, 15 +18 seconds (retention interval).
What were Peterson and Peterson’s results?
I found that the number of trigrams were called significantly decreased as a retention interval increased and after the 18 second retention interval, only 10% of the trigrams were successfully recalled.
What was Peterson and Peterson’s conclusion?
The results suggested that short-term memory may have a very short duration of around 18 seconds, unless we repeat something over and over (verbal/maintenance rehearsal0
What type of relationship did Peter and Peterson find? Explain your answer.
A negative correlation- as the retention interval increases the number of trigrams recalled decreases.
Who studied the duration of the long-term memory and what was their aim?
Bahrick et al (1975) and their aim was to investigate the duration of the LTM?
What was Bahrick’s method?
Studied 392 participants from Ohio who were aged between 17 and 74. High school yearbooks were obtained from the ppts or directly from some schools.
Recall was tested in various way including:
(1) photo-recognition test consisting of 50 photos, some form the ppts high school yearbook.
(2) free recall test where ppts recalled all the names of their graduating class.
What was Bahrick’s results?
Participants who were tested within 15 year of graduation were ably 90 prevent accurate in photo recognition. After 48 years, recall declined to about 70 percent for photo recognition. Free recall was worse than recognition. After 15 years, this was about 60 percent dropping to 30 percent after 48 years.
