Flashcards in Lecture 7 Deck (27):
What did William James (1890) propose?
A dual system view
Primary memory: the contents of memory that are immediately available
Secondary memory: much larger and is the repository of all our previous experiences
Definition of capacity
How much information can be stored
Definition of duration
How long the information is available in the store
What are saccades
Rapidly moving eyes in small movements
4 main points of sensory storage
- all sensory information that enters the senses is held in a form of memory called the sensory buffer
- sensory storage provides a continuity in our perception so we are not shocked when we re-enter a room with the people we just saw
- sensory buffer provides storage for the incoming information until attention can act on it
- it is a hidden memory system, as it works without you being consciously aware of it
Saccadic suppression is...
When the brain suppresses visual processing for a brief period of time
Iconic memory is a system for what..
Echoic memory is a sensory system for what..
What did George Sperling (1960) do?
- displayed cards with various numbers of letters (between 2 and 12) for 50 milliseconds
- because the letters were only shown for shorts amounts of time, the ppts didn't have time to scan the image so had to use their memory
- ppts were asked to report as many items as they could
- most ppts could report the displays if there were less than 5 items
What was Sperlings partial report?
- same experiment as whole report
- but after seeing letters there would be a high, medium or low tone sounded
- this would indicate what row of letters he wanted ppts to recall
- concluded there was no limit to sensory memory, the limit is the speed with which you can report the items
How quickly is information lost?
- Sperling used his experiment as done before but altered the time between showing the letters and signalling which line needed to be recalled
- after a delay of 300 milliseconds participants had already forgotten half the items available
- after 1 second participants were no better with partial report than whole report
Key feature of iconic memory
Information decays rapidly, meaning attention needs to act on the relevant information before it decays
What has been found through masking studies?
- info held in sensory memory can be overwritten
- if a target and a mask are very close in time, they merge in iconic memory
- this could lead to problems identifying the target
What did Haber and Standing (1969) do?
- alternated a word a circle in quick succession
- at 250-300 milliseconds the circle and word appeared together
- meaning there can be a small delay between visual images and you don't lose continuity
What did Murdoch (1962) do?
- free recall task
- presented a list of words (10-40) and asked to memorise them
- ppts asked to recall the list immediately after finishing hearing it
- they were likely to get words correct based on their position in the list e.g. Beginning, middle, end
What is the primacy effect?
First section of recall is rehearsed and therefore is in memory longer so can be recalled better
Thought to represent long term memory
What is the recency effect?
Recall is better at the end of the list because the words are fresh in your memory and don't decay as quickly as the ones in the middle
Thought to represent short term memory
What did Postman and Phillips (1965) do?
- ppts given words to learn
- ppts either immediately recalled as many items as they could or counted backwards at the end of the trial before recalling as many as they could
- counted back in 3s for either 15 or 30 seconds
- suggested recency part is eliminated by counting as it stops rehearsal, representing info in STM
What did Peterson and Peterson (1959) do?
- ppts shown 3 nonsense syllables and after a few seconds a number appeared
- they had to count down in 3s from that number until told to stop
- majority could remember syllables after 8 seconds
- 2% could remember after 18 seconds
- suggested STM has a maximum duration of 18 seconds without rehearsal
What did Waugh and Norman (1965) do?
- used a design where ppts had to recall a specific number from a sequence
- asked to report the item that came after the probe number
- act of determining the next letter prevented rehearsal and eliminated recency effect
What did Ebbinghaus do?
- anticipation method used to try and determine how much info can be retained over a short period of time
- 1 to 6 nonsense syllables took one time to recall, but after 6 it took several times to recall
- number of readings increased when he got to around 6-7 items
What did Miller (1956) do?
- used digit span task
- asked participants to repeat back the sequence they were shown in the correct order
- found people can remember between 5 to 9 items
- where the 7 +/- 2 items came from
What is chunking?
Dividing information into 'meaningful chunks'
Like a phone number
- our working memory will find information we already have in our long term memory to send feedback to our STM and divide our information into efficient chunks
What is STM duration for forgetting?
STM has a duration that lasts no more than 10 seconds without active rehearsal
- Peterson and Peterson experiment used all the letters of the alphabet in their syllables which could have caused interference because after several trials the combinations of syllables will start to look the same
Two types of interference
Retroactive interference: when information you are storing makes it hard to remember something from previously
Proactive interference: when information previously stored makes it harder to remember something new e.g. remembering a new boyfriend/friend name
What did Conrad (1964) do for encoding?
- 6 letter sequences that sounded similar or dissimilar e.g. PBD or LKT
- recall accuracy dropped when letters were phonologically/acoustically similar because confusion was caused
- repeated the experiment and presented items visually
- found the same effect
- this is called acoustic confusion