Memory Flashcards
Define coding
The format in which information is stored
Who did research on coding?
Baddeley
Outline Baddeley’s procedure
Four groups were given lists to remember
A) acoustically similar words
B) acoustically dissimilar words
C) semantically similar words
D) semantically dissimilar words
They were asked to recall the words some had to immediately(STM) others had to wait 20 minutes (LTM)
Result of Baddeley’s experiment for STM
Acoustically dissimilar words were recalled more accurately than acoustically similar words
Results of Baddeley’s experiment for LTM
Semantically dissimilar words were recalled more accurately than semantically similar words
Conclusions for Baddeley’s experiment
STM - acoustic confusion, coded acoustically
LTM - semantic confusion, codes semantically
Negative evaluation of Baddeley’s experiment
The words used had no personal meaning to the participants so the stimuli was artificial
What is capacity?
Amount of information that can be held
Research for capacity
Jacobs and Miller
Method for Jacob’s study
Aim - see how much info STM can hold at one time (digit span)
Procedure: gave a certain number of digits then the participants recalled in correct order. If recalled correctly, amount of digits increased. Determines individuals digit span/STM capacity
Results of Jacob’s study
Participants had a mean score of 7 letters in order and 9 numbers in order
Negative evaluation of Jacob’s study
This was conducted a long time ago so there was a lack of control on extraneous variables. This could mean the results were not valid as there was confounding variables that were not controlled
What did Miller’s study discover?
Instead as keeping the information as individuals, he unit of information can be increased by chunking
What is duration?
Length of time information can be held
Who conducted STM duration research?
Peterson and Peterson
Method for Peterson and Peterson’s study
24 students were given a trigram, as well as a 3 digit number to remember. The student had to count backwards from this number(prevents mental reversal) told to stop counting at different seconds(eg. 3,9,18)
Results for Peterson and Peterson’s study
Amount recalled correctly:
3 seconds - 90%
18 seconds - 5%
(Significant difference between them)
Conclusion for Peterson and Peterson’s study
STM has a very short duration unless it is repeated over and over again(verbal rehearsal)
Negative evaluation of Peterson and Peterson’s study
Contains an artificial stimulus trying to remember constant syllabus’s does not happen in real life so lacks ecological validity
Who did a study on long term duration?
Bahrick et al
What is the duration of sensory memory?
250ms
How is information encoded in the sensory memory?
Sense specific
What is the capacity of sensory memory?
Unlimited
What is the duration of short term memory?
18-30 seconds
How is information encoded in short term memory
Acoustically
What is the capacity of short term memory?
7 +/- 2 items
What is the duration of the long term memory?
Potentially a lifetime
How is information encoded in the long term memory ?
Semantically
What is the capacity of the long term memory?
Unlimited
What did Sperling do?
Studied the sensory memory for vision by using a device that can flash pictorial stimuli onto a blank screen for very brief instances. Using this device, Sperling was able to ask subjects to remember as many letters as they could from a grid of 12 symbols that he was going to display for 50ms. He found that while they could only recall around 4 of the symbols before the grid faded from their sensory memory, they typically reported seeing a lot more than they had time to report
Who is used for duration of the long term memory?
Bahrick et al
What did Bahrick et al do?
Investigated the duration of LTM used a sample of 392 American ex-high school students aged between 17 and 74. The time since leaving high school was up to 48 years. The participants were tested in several ways: free recall, a photo recognition test. The participants were asked to identify their former classmates from a set of 50 photos
What were the findings of Bahrick’s study on the duration of long term memory?
He found that the recognition group was 90% accurate after 14 years and 60% after 47 years
Who is used to evaluate the capacity of long term memory?
Wagenaar
What did Wagenaar do?
Creates a diary of 2400 events over 6 years and tested himself in recall of events rather than dates, finding he too had excellent recall, again suggesting the capacity of LTM is extremely large
How is information encoded in the phonological loop?
Acoustically
What is the capacity of the phonological loop?
Limited
What are the 4 memory retrieval technique used in the cognitive interview?
- Context reinstatement
- Report everything
- Change perspective
- Change order
What does context reinstatement involve?
Interviewed should instruct witness to mentally return to place of the event and recall the environment and emotional context
What does report everything involve?
Interviewer should instruct witness to recall maximum amount of information as possible, even if it seems trivial
What does change perspective involve?
Interviewer should instruct witness to describe events from the perspective of someone else involved
What does change order involve?
Interviewer should ask the witness to recount the event in a different chronological order
What does the phonological loop do?
Deals with spoken and written material
What are the two parts of the phonological loop?
- Phonological store
2. Articulatory control process
What does the phonological store do?
Processes speech perception and stores spoken words we hear for 1-2 seconds
What does the articulatory control process do?
Processes speech production, and rehearses and stores verbal information from the phonological store
How is information encoded in the Visio-spatial sketch pad?
Visually
What does the Visuo spatial sketch pad do
Used for navigation
What is evidence for the visuo spatial sketch pad
Todd and Markus
What did Todd and Marois do?
Found more activity in the left half of the brain of people carrying out visual working memory tasks, but more in the right half of the brain during spatial tasks, suggesting the visuo spatial sketch pad having distinct visual and spatial components
How is information encoded into the episodic buffer?
Modality free
What is the capacity of the episodic buffer?
Limited
What is the episodic buffer?
A temporary store that integrates information from the other components and maintains a sense of time, so that events occur in a continuing sequence
How is information endowed into the central executive?
Modality free
What is the capacity of the central executive?
Limited
What does the central executive do?
- monitors and coordinates the operation of the space systems
What did D’Esposito et al find?
Found using fMRI scans that the prefrontal cortex was activated when verbal and spatial tasks were performed simultaneously, suggesting the brain area to be associated with the workings of the CE
If you imagine yourself favourite song, which part of the working memory are you using?
Phonological loop
What is the cognitive interview technique?
It is a questioning technique used by the police to enhance retrieval of information from witnesses’ memory
