Memory Studies Flashcards
Sperling
Sperling studied the capacity of the sensory register.
One group was asked to remember as many letters as possible, and one group was asked to recall letters from only one row.
The dependant variable was how many words were recalled.
Method:
4 by 3 grids of letters, were displayed for 50 milliseconds.
The paricipants in the one grid recall, would know which grid to recall, based off a sound, that was played after seeing the grid.
Results: when participants were asked to recall the whole grid, the avarage nmber of letters recalled was 4-5 letters.
When participants were asked to recall just one row, they could usually recall 3 letters.
Conclusion: he concluded that the sensory register has a high capacity , because participants can remember a whole row on average, however, it is limited by its short duration, which is why participants couldn’t remember more than 5 letters. This simply means we lose all the information, before we can even recall it.
Jacobs
He investigated the capacity of short-term memory.
He showed participants strings of random letters, or digits, and then asked them to repeat them back in the order that they were first presented in.
Across trials, Jacobs increased the length of the strings, in order to determine the maximum number of letters or digits , his participants could recall.
He concluded that participants could recall an avarage of 7+-2 letters.
So the capacity of the STM is fixed.
Bahricks
He investigated the duration of long-term memory.
Method: He asked his participants to remember the names of their old classmates.
He tested participants that left high school 15 years ago, and 48 years ago.
In one condition, he asked participants to remeber the names of their old classmates (active recall).
And then he showed some participants the names of their old classmates, and asked them to match the names to pictures of them.
FINDINGS: recall group:
15 years since highschool: 60 % remembrance rate
48 years since highschool: 30% remembrance rate.
Recognition group:
15 years from high school: 90% remembrance rate.
48 years from highschool: 80% remembrance rate
He concluded that the duration of long term memory is very long, and that recall is much better when we are asked to recognise it, rather than recall it.
Baddeley.
He investigated the coding of short-term memory and long-term memory.
Baddeley asked his participants to memorise a whole list of words.
To test STM, he asked participants to recall the word list immediatly.
To test the LTM, he asked his participants to recall the word lost in 20 minutes.
Baddeley separated the participnats in 4 equal groups:
1. Words that sounded the same.
2.Words that didnt sound the same
3. Words that all have the same similar meaning.
4. Words that don’t have similar meanings.
Results: when participants were asked to recall words immediately, they performed worse on the word list with words that sounded the same., this is because the STM is acoustically code, and participants are more likely to confuse the words.
When participants were asked to recall words 30 minutes later, they performed worse on the word list which had words with similar meanings, this is because the LTM is semantically coded, and participants are more likely to confuse the words.
HM
A doctor removed HM hippocampus during a surgical procedure, and he completely lost his long-term memory.
When asked to recall a series of letter, he could recall them immediately, however when asked to recall them 30 minutes later, he couldn’t even remember that he has to recall anything.
This proves that each memory store can be damaged independently.
KF
KF, was a patient which suffered severe brain damage from a motorbike accident.
When he woke up, his short-term memory was destroyed.
When asked to remember a set of words, he could only remember a span of one word.
However, when asked to recall a set of pictures, he could memorise them perfectly.
This means that KF could recall visual information, but not verbal information, this proves that we have multiple types of short-term memory.
Underwood.
He investigated the effects of learning multiple other word list’s, on participant’s ability to recall most recently word list
Method: one group of participants had to memorise just one list of words, and then other groups had to memorise more lists.
Findings: after 20 hours, they ere asked to recall the most recently learned word list.
Findings: group with only one word list to recall, only had 80% accuracy on avarage.
Group with other word list to recall, had a very low 20% accuracy of recall.
Underwood and postman.
Participants were divided into two groups.
Both groups were asked to learn a list of words in pairs.
The control group, only had to learn one list of word pairs, whereas the experimental group had to recall two lists of similar word pairs.
They were then asked to recall the words in the first word-pair list.
Findings: the control group, memorised the list, better than the experimental group.
This proves retroactive interference.
Godden and Baddeley.
They made participants learn word lists on land and underwater, then their recall of the list of words was tested.
Some participants were tested in the same context that they had to learn the list of words in.
And some participnats were tested in a different context.
Results: participants recall, was better when they were tested in the same context as they learned the information.
Therefore the experiment proves the use of external cues for memory retrieval.
The weapons study ( Johnson and Scotts).
Aim: To investigate the effect of anxiety on memory.
Participants were made to sit in a room together, while two confederates were having a loud discussion in a room near them.
The participants were then divided into two equal groups:
1. Low anxiety: saw a man walk out a room, carrying a pen, with greasy hands.
2. High anxiety: Saw a man walk out of a room, carrying a knife, covered with blood.
Participants were then asked to identify the man from 50 different photographs.
Participants in low anxiety, were 49 % accurate, whereas
Participants in high anxiety, were 33% accurate.
This proves that too much anxiety, affects memory recall accuracy.
Loftus and Palmer.
Made participants watch car crashes, and then asked them to remember the participants everything about the experiment.
They were asked the speed of the car, however, in each experimental group, they manipulated the way in which they would word the question.
There were 5 different groups. Which were asked the question in a more or less leading way..
They found that the way in which they asked the question, influenced the participants memory of how quickly the car was going.
EXPERIMENT2: A couple weeks later, they asked the participnats,
“Did you see the broken glass”.
Some participants said they did, despite there being no broken glass.
This is a false memory.
This proves that asking leading questions, can influence a persons memory, thus causing them to have false memories.
