remembering brain 2 Flashcards
working memory
information currently in mind is manipulated
decision making and goal-directed behaviour relies on WM
Baddeley’s model of working memory components
separate STM stores central executive - controls slave systems visuospatial sketchpad phonological loop - verbal episodic buffer - later addition
episodic buffer
later addition
slave system to central executive
retains episodic info from LTM for limited time - e.g., social rules
central executive
refreshes info in the stores and manipulates that info
in prefrontal cortex
phonological store brain region
parietal lobe
phonological loop and visuospatial sketch pad are __ (independent/cooperative)
behavioural and brain scan evidence
independent
if do 2 tasks involved one = worse
verbal = left hemisphere
visuospatial = right hemisphere
digit span test
read back numbers
increase by 1
stop when 2 mistakes in a row
make harder - read out backwards
operation span
maths equations between words recall words dual task predicts verbal abilities in reading comprehension - make harder - harder maths Qs
capacity of phonological STM
Milner (1956) - 5-9 items - chunking
other claim lower - around 4
why is chunking critisised
required LTM
less capacity for longer words - not chunking
span length = lower for phonologically similar words - capacity = based on phonological characteristics
factor which may limit span of verbal STM =
opportunity to rehearse
when hold word in mind and mouth irrelevant speech - WM capacity = lower
components of phonological loop
phonological store
rehearsal system
brain locations of components of phonological loop
phonological store = left supramarginal gyrus (inferior parietal lobe)
rehearsal system = broca’s areas (inferior frontal cortex)
models of visuospatial STM capacity
slot model
resource model
slot model
small number of memory slots
each responsible for storing a single visual object with fixed precision
resource model
no upper limit
additional items = less precise memory for the array
additional support over slot model
Luck and Vogel - supporting slot model
Ps able to retain info for 4 objects
able to retain 16 individual features - provided distributed across the 4 objects
bays, catalao and hussain - evidence for resource model
the more items held in memory the less precisely each could be recalled
neural correlates of visuospatial STM
- face information
fusiform face area
neural correlates of visuospatial STM
- place information
parahippocampal place area
what happens to WM in delay period
even though info not visible - engaged brain regions that usually represent this info
brain region with critical role in WM tasks
prefrontal cortex
delay response task - PFC in WM
PFC lesions affect performance in retaining food location info
- no damage with associative memory task - specific to PFC
response of PFC neurons
hold info in WM
sustained activation during delay period
same neurons active for different tasks
interaction between PFC and posterior cortex
goal - remains in WM (PFC)
directs activation within posterior parts of brain to gain knowledge
Petrides model - divisions of PFC
dorsal lateral PFC = manipulates info + monitors accuracy
ventral lateral PFC = maintenance of info - finds right representation in posterior brain for current goal
modal model
sensory > STM > LTM
neuropsychological evidence for separate STM and LTM
HM - damage to LTM/intact STM
KF - damage to STM/intact LTM
unitary model of WM/STM - cowan model
WM is temporary activation of LTM
capacity limitations cannot be explained (interferences increases)
cowan model - focus of attention
activates relevant portions of the LTM
some are more relevant to goal - enter focus of attention
cog neuro evidence for cowan model
WM entails temporary activations in parts of the brain involved in LT storage
role of PFC in LTM
- maintenance and active control of info
- encoding and retrieval
lateralisation of PFC encoding
encoding words or semantic materials = left PFC
encoding spatial info or faces = right PFC
PFC and retrieval
PFC aids the organisation, selection, monitoring and evaluation of processing that occurs at retrieval
PFC retrieval brain region
DLPFC
increased activity in free recall, recall vs recognition and low confidence judgement tests
PFC free recall
PFC damage impacts free recall more than recognition
as PFC engaged in free recall via connection with MTL - strategic search of memory
recognition = search not required to same extent
PFC source monitoring
PFC is involved in placing an event in context
requires active evaluation before able to access origin of memory
PFC damage = difficulty with this
confabulating
damage in PFC
narratives that include false memories
