Memory Flashcards
What is Memory?
Memory is the process of retaining information for some time after it is learned.
- It is stored knowledge
Do we have different types of memory?
Yes - the most important distinction is made between short-term and long-term memory
To distinguish between short-term memory and long-term memory we look at:
- Capacity: how much the store holds
- Duration: the period of time
- Encoding: putting something into a code in order to store it in the memory
Capacity
- Long Term Memory is unlimited
- 5 to 9 or 7+ or -2
Capacity - Short Term Memory
In 1887 Jacob did a similar experiment (used numbers or letters) and found that the average number of items recalled correctly was between 5 to 9.
Limitations with Jacob’s study?
- Lacked ecological validity
- How does the experiment explain how we remember a word that has nine or ten letters after seeing it once? - That’s not representative of how peoples memories work.
Miller
- Argued that immediate memory is 7(+ or -2)
- He said that seven singular digits OR chunks of information could be remembered at any one time
- Simon built upon Miller’s theory and concluded that ‘CHUNKS’ could consist of phrases/categories etc
So far we know that:
- The capacity of Long Term Memory is unlimited
- What is the capacity of the Short Term Memory? - (seven plus or minus two)
Recency Effect
- This is called the recency effect
- People have a good memory for the most recent information (because these items are at the forefront of the short term store)
- Last things in your mind/Short Term Memory.
- Most people have moonlight and PJ’s because they’re the ones most likely rehearsed.
- Pushed into the Long Term Memory, this is called the Primarycy Effect
Glanzer and Cunitz
- Investigated the recency effect by having their participants count backwards in threes for ten secs after seeing the words
- This eliminated the recency effect. Other words were recalled because they had been rehearsed an transferred into the Long Term store. The last items were fragile and so were forgotten.
Duration of the Short Term Memory
- This next experiment was first carried out by married couple Peterson & Peterson (1959)
- Got students to recall combinations of 3 letters (trigrams), after longer and longer intervals.
- During the intervals, students were prevented from rehearsing by a counting task
- On the next screen, you will see a trigram for a few seconds
- A 3-dgit number will then appear in its place. When this happens, start counting backwards in 3’s from the number until you are told to stop
Peterson & Peterson study
- Study of duration of Short Term Memory Lab Experiment
Procedure:
- Participants were shown trigrams which they had to recall in the correct order after a delay of 3, 6, 9, 12, 15, or 18 seconds
- Before recall participants had to count backwards in threes from a random high number (e.g. 866)
Peterson & Peterson study
Findings:
There was a rapid increase in forgetting as the time delay increased. As time increase recall decrease
-After 3 secs 80% of trigrams were recalled
-6 secs 50%
- 18 secs less than 10% were recalled
- Their findings suggest that our STM fades in under a half a minute if we are not rehearsing it:
- After only 3secs, 80% recalled correctly.
- After 18secs, fewer than 10% recalled correctly.
- Recall got progressively worse as the delay grew longer
- Negative Correlation
Bahrick 1975
- studied Very - Long Term Memory
- lacked in mundane realism
Procedures:
- Graduates in USA tracked over a fifty year period,
- The ex-pupils were asked to recall the names of any of their classmates. They were also shown a set of photographs and asked to identify photographs and asked to identify individuals.
Bahrick 1975
Findings:
- 90% accuracy for face and name recognition even for participants who had left school up to 34 years ago
- Supporting the notion that people do have very genuine Long Term Memories
