memory part 1 Flashcards
memory
process of using information that was obtained in the past in order to generate some cognitive function
encoding
initial processing of information so that it is represented in the nervous system
storage
when the information encoded by the nervous system remains encoded in some form for a longer duration than immediate processing
retriveal
brain accessing stored memory for some cognitive purpose
capacity
how much information a memory system can hold - different types of memory have different capacities
duration
how long information remains in memory - again. de[ends on the type of information and type of memory
modal model of memory
model of memory proposed by atkinson and shiffrin in 1968
highly influential because they suggested the theory that there are three basic kinds of memory, each with its own capacity and duration
what is the first step in the modal model
sensory memory - large capacity (takes in a lot of sensory info before it can be processed) and short duration (around 1 second max)
its purpose is to hold information in place so that it may be processed. Only a fraction of information ends up being processed, a selection process determined by attention
what is the second step in the modal model of memory
information that ends up being processed from sensory memory flows into short term memory, which has a smaller capacity than sensory memory, but a longer duration in the range of 15-30 seconds
unlike sensory memory, stm is capable of producing a behavioural output - like repeating back a phone number
what is the third step in the modal model of memory
a small fraction of information in short term memory goes to long term memory (ltm) via encoding processes (rehearsal)
there is no limit on duration or capacity of ltm (as far as we know)
why is the modal model of memory often called an information processing model
because it likens our processing of information to encoding and storing information into a computer
persistence of vision
we can sometimes directly see information that entered our eye moments ago - think waving a sparkler back and forth
partial report experiment
an experiment designed by george sperling (1960) in order to test how much information is retained in sensory memory
ps presented with stimuli consisting of three words of letters - a grid of letters
two conditions:
whole report:
ps asked to report as many letters as they could- found that they generally reported letters from one of the rows, suggesting that whichever row they happened to be paying attention to was the row that was available to report
partial report:
ps asked to report letters from a specific line, but only after they had seen the grid paired with an auditory tone which indicated which row ps had to report
what were the findings of the partial report experiment
when the tone was presented very soon after the grid disappeared, ps could still remember all of the letters in the indicated row
suggests that ps had the entire letter grid present in their sensory memory, and, for a brief moment, could decided which rows to pay attention to in order to bring them into short term memory to report them
capacity of sensory memory is quite high?
increased delay = capacity to accurately report rows decreases
after 1 second, ps couldn’t remember anything
suggests duration of sensory memory is around 1 second
iconic memory
sperling’s name for the high capacity/short duration form of visual memory he found in his study
it is based on the fact that the memory is something like a photographic image or ‘icon’
echoic memory
similar to iconic memory but is an auditory instead of visual form of sensory memory
what sort of information does short term memory hold?
information that has been selected by attention for processing - its function is to hold information in place until it can be used for some behavioural task
what is the capacity of short term memory
auditory domain: around 7 items (give or take 2)
visual domain: around 4 items
how was the capacity of auditory stm discovered
miller (1956) presented ps with lists of letters, numbers and works, and asked them to repeat, in order
the magical number seven plus or minus two
stm auditory capacity - seems stable across tests and years - fixed feature of our brains
chunk
a combination of letters, numbers or sounds that constitute a meaningful whole
we remember information in stm in chunks
the capacity to chunk information into larger units depends on engaging long term memory
how do we measure visual short term memory? (vstm)
change detection tasks - images shown one after the other - either identical or with some property changed
memory expertise
depends on chunking, not better memory
rehearsal
repetition of information in short term memory which reactivates initial encoding, and keeps things in stm
brown peterson task
short term memory task in which ps are told to remember three letters (trigram)
but right after being presented with the letters they are told to count backwards by 3s from a 2 digit number
under this conditions, trigram memory fades after 15 to 18 seconds
suggests that duration of stm in the absence of rehearsal is about 15 seconds
decay model of forgetting
forgetting occurs simply becayse of the passage of time
interference model of forgetting
new information that comes into memory serves to displace older information
proactive interference
information causes you to forget something you learn in the future
ex. reading a book then studying bio - info in book causes memory for bio to be inhibited
retroactive interfere
information causes you to forget something from the past
ex. reading a book and studying for bio - studying for bio causes you to forget book
peterson and peterson reanalysis
some letters from previous trials interfere with memory in current trials - suggest that in the brown peterson task both interference and decay contribute to loss of memory in stm
carried out by keppel and underwood
working memory modal
baddeley (1974) - updated addition to short term memory in stm
short term memory isn’t just a storage buffer, instead it is an active system that can be used to mentally manipulate information as needed based on current tasks
short term memory consists of three units
- visual sketch pad
- phonological loop
- central executive
visual sketch pad
visual portion of stm - can be used to analyze and manipulate information in memory - for example, mentally rotating an object
phonological loop
auditory portion of stm - allows information to be repeated so that it may be used or analyzed
central executive
determines what information makes it into working memory and toggles between visual and auditory memory stores
acoustic confusions
people have a hard time memorizing letters that sound similar to each other than letters that sound different
its because when we replay sounds we have just heard, they have the same auditory properties as the original
visual and auditory buffers in WM model
separate and don’t interfere with each other
what are the two roles of the central executive
coordinating between the phonological loop and the visual sketchpad and determining which information makes it to the stm
research suggests that individual differences in memory may be due to differences in ability to filter out irrelevant information
