memory Flashcards
sensory memory in modal
initial stage that holds all incoming information for fractions of a second
short term memory in modal
holds 5-7 items for about 10-15 seconds
long term memory in modal
holds large amounts of information for years or decades
modal model of memory
input into sensory memory
transfers to short term memory
rehearsal control processes
lost by decay
transfers to long tem memory
control processes in modal model
active processes that can be controlled by the person
allows us to make short term memory more efficient
- rehearsal
- strategies used to make stimuli more memorable
- strategies of attention to help focus
sensory memory
retention of effects of sensory stimulation
information decays very quickly
Sterling measured capacity and duration
Sperling
presented letters flashing quickly onto screen
participants asked to report as many letters as possible
whole report - report as many as they could
partial report - report specific row
best performance
delay partial report - presentation delayed after letter shown
worst performance
short term memory
stores small amounts of information for a brief duration
includes new information received from the sensory memory and information recalled from long term
- that we perceive as the present
duration of short term
15-20 seconds
tested with recalling letter and digit series tasks
can decay = reduction in performance after delay
also due to competing stimuli
poor performance after longer intervals mostly occurred towards end
interference caused forgetting
interference
proactive - previous interferes with new information
retroactive - new information interferes with existing knowledge
capacity of short term
digit span task
- average 5-9 items (7)
chunking
- small units can be combined into larger meaningful units
- effective learning strategy and STM control processes
chunk
- collection of elements strongly associated
- increases capacity
working memory
limited capacity system for temporary storage of information
WM differs from STM
- STM holds for brief period
- WM stores, processes and manipulates information
- active during complex cognition
- related to executive attention (requires information)
parts of working memory
phonological loop
- verbal and auditory information
- only holds information for few seconds
articulatory rehearsal process - rehearsal keeps information from decaying
central executive
- coordinates between them
visuospatial sketchpad
- visual and spatial information
- holds in absence of physical visual stimulus
central executive
acts as the attention controller and accesses long term memory
focuses, divides and switches attention
controls suppression of irrelevant information
capacity of WM
affected by interference
phonological similarity effect
- letters of words that sound similar are comfused
articulator suppression
- speaking prevents one from rehearsing items to be remembered
word length effect
- memory for word lists better for short words
- takes longer to rehearse long words and produce them in recall
episodic buffer
added to WM in 2009
backup store that can hold information longer
has greater capacity than phonological loop or visuospatial sketchpad
uses chunking
communicates with long term and working memory components
neural basis of WM influenced by context
there is not one neural correlate of WM
behaviour of neurons being active while controlled attention mediates different processes
WM not localised
prefrontal cortex
processes incoming visual and auditory information
Funahashi
single cell recording from monkeys prefrontal cortex during delated response task
neurons that responded to stimulus location kept firing for the delay time
monkeys without prefrontal cortex have difficulty holding information in working memory
long term memory
archive of information about past events and knowledge
works closely with working memory
storage 30 seconds ago - forever
more recent memories are more detailed
consolidation = process of moving information from WM to LTM
types of long term memory
explicit (declarative)
- conscious - know you remember
- experiences and events
episodic (experiences) and semantic (facts and knowledge)
implicit (non-declarative)
- unconscious
procedural - how to do things
priming
classical conditioning (associations)
serial position curve
distinction between short and long term memories
read word list - write all words remembered
memory better for words presented at beginning of list - primacy effect
and for those at the end - recency effect
coding
happens on all levels
- auditory, visual and semantic
sensory coding is encoded into mental coding
recognition memory - identification of previously encountered stimulus
patient HM and KF
HM = no hippocampus
retained STM but no new LTM
KF = damage to parental lobe
- impaired STM but good LTM
highlights role of hippocampus for encoding episodic information
and parietal for attention and working memory
double dissociation
occurs if damage to one area of the brain causes function A to be absent while function B is present
and damage to area causes function B to be absent while function A is present
declarative memory
episodic memory
- involves mental time travel
- tied to personal experience
- self knowing
- can overlap with autobiographic memory
semantic memory
- does not involve mental time travel
- general knowledge and facts
- knowing
- often result of episodic memories
autobiographical
- memory for specific experiences from our life, can include both semantic and episodic
- involves mental time travel
- multidimensional
active reconstruction
based on combining episodic, semantic, sensory and self relevant information
what information is remembered the best?
significant events
emotional events
transition points
not all information remembered the same
almost nothing before 5
childhood remembered well
fewer memories encoded in middle of life
recent events remembered better
exceptional stimuli
emotional events - more easily and vividly remembered
emotion improves memory
becomes greater with time eg weapon focus
flashbulb memories
memories for hr circumstances surrounding shocking, important events
culturally important communal memories
highly affected by rehearsal (eg talking and media) and personal emotion
non declarative memories
implicit - procedural, priming and conditioning
procedural - skills
priming - unconscious, implicit, pre activation of relevant features by an unattended stimulus
conditioning - associating two not naturally related things via experience
implicit memories
occurs when learning from experience is not accompanied by conscious remembering of acquisition
Patient HM and procedural
no new episodic or semantic
but could make procedural
engrams
first physical traces of memory
recycled for new memories when they have been encoded
consolidation
transforms new memories from fragile state to more permanent state 9change over time)
initiate in hippocampus and distributed in different parts of the cortex
getting information into LTM
encoding
- acquiring information and transforming it into memory
retrieval
- transferring information from LTM to working memory
maintenance rehearsal
- repetition of stimuli that maintains information but does not transfer it to LTM
elaborative rehearsal
- using meanings and connections to help transfer information to LTM
levels of processing theory
memory depends on how much information is encoded (depth of processing)
shallow processing
- little attention to meaning
- focus on physical features
- results in poor memory
deep processing
- close attention to meaning
- connecting new information to existing
- results in better memory
factors that aid encoding
visual imagery
self reference effect (memory better if you can relate it to something)
generation effect (generating relevant information)
organising to be remember information
retrieval practise
drawing
retrieval
process of transferring information from LTM back into WM
most vulnerable process of memory
due to:
- many memory failures are failures of retrieval
- not done properly or correctly
emotion interferes
- positive easier than negative
context interferes
- easier to retrieve information in a similar situation or mood compared to when information is learnt
facts that aid retrieval
cues
matching conditions
encoding specificity - context dependant
mood matching - state dependant
memory consolidation
transforms new memories from fragile stat into more permanent state
synaptic - rapid, occurs at synapses (faster)
systems - gradual, reorganisation of neural circuits (slow)
synaptic consolidation
Hebb
- learning and memory represent in brain by physiological changes at synapse
- neural record of experience
long term potentiation
- strengthening of synaptic transmission by enhanced firing of neurons after repeated stimulation
- structural changes and enhanced responding
system consolidation
gradual reorganisation of neural connections over time
after encoding, activity of the hippocampus fades with time
connections between the cortex and the hippocampus are initially strong
as time passes, activity occurs between the hippocampus and the cortex
= reactivation
over time, connections formed between cortical areas
connections between hippocampus and cortex weakened and vanish
= cross cortical consolidation
factors affecting consolidation
memory consolidation enhanced during sleep
- stops interference from environmental stimuli
some memories are consolidated more than others
retrieved memories become fragile and are consolidated again = reonsolidation
memory constantly constructed and remodelled in response to learning and current conditions
retrograde amnesia
loss of memory for events prior to trauma
graded amnesia
memory for recent events more fragile than for remote
anterograde amnesia
inability to form new long term memories for events after trauma
effects of time on memories
semantic - increases infill 6- then slowly decreases
implicit - not effected much
episodic - deteriorates rapidly after 60
- recognition performance better than free recall
constructive nature of memory
memory = what happened + persons knowledge, experiences and expectations
memory influenced by inferences based on peoples experiences and knowledge
Bartlett
participants remember a story from a different culture
repeated reproduction
over time reproduction became shorter and less accurate
changed story to make more consistent with own culture and stereotypes
scripts and schemas
concept of a sequence of actions that usually occurs during a particular experience
schema - knowledge about some aspect of the environment
effect of scripts and schemas on memory
memory can include information not actually experienced but inferred
because it is expected and consistent with schema
can lead to errors and false memories
source monitoring
source memory - process of determining origins of our memories
source monitoring error - misidentifiying source of memory
enhanced probability of evaluating a statement as true after repeated presentation
based on familiarity
cryptoamnesia
unconscious plagiarism of another work due to lack of recognition of its original source
power of suggestion
misinformation effect
- misleading information presented after someone witnesses an event can change how that person later describes it
errors in eyewitness testimony
mistaken identity
errors due to attention or arousal
errors due to familiarity (source monitoring)
constructive nature (inference)
suggestive questioning (misinformation)
inaccurate memories and inequalities
social hierarchy in who we believe
making inferences based on biased beliefs
face memory worse for groups we don’t interact with as much
people trust own memories
