lecture 6 - 7 sins of memory Flashcards
Ebbinghaus curve =
forgetting over time
BUT used nonsense syllables - not ecologically valid
permastore
memories not transferred to permastore (analogous to consolidation) are vulnerable to forgetting
‘given 2 associations of the same strength but of different ages…’
the older falls off less rapidly in given length of time (Jost)
half-life of memory trace reflects…
success of initial learning
Brewer et al: magnitude of activations in _________ & in ____________ predicted which photos were later remembered well, less well and forgotten
right PFC & bilateral parahippocampal cortex
1) remembered well = greater activation
2) less well = medium activation
3) forgotten = least activation
accelerated long term forgetting (in some patient groups e.g. temporal lobe epilepsy)
e.g. patient SK: much greater forgetting at later periods after learning
often goes undetected by standard memory tests
normal forgetting in shorter terms
mechanisms of forgetting: 1) decay
important in STM & sensory memory
rapid forgetting in first 12 secs
less likely to be good explanation of LTM
Peterson & Peterson: method for assessing decay = count backward and then recall trigram
Decay = central tenet of ‘Time-Based Resource Sharing Model’
learn something > distractor task (memory decays) > refresher task (memory is recovered)
model assumes that during complex WM span tasks, attention is frequently switched from processing to reactivate decaying memory traces before complete loss
the reactivation process (of the Time-based resource sharing model) is efficient from age _______
7 onward & increases in efficiency until late adolescence
McGeoch criticised decay theory:
improper as a scientific theory - doesn’t specify a mechanism
mechanisms of forgetting: 2) interference
more closely related items = more interference (item-specific)
Factors in retroactive interference: ‘Two-factor inference theory’
1) unlearning = earlier represenations are weakened/destroyed by later learning
2) response competition = earlier representations still remain after later larning but problems arise from response competition at retrieval
retroactive interference as a factor in anterograde amnesia?
if amnesics did any task between learning and response - memory was worse/no memory at all
some of their mempry impairment may be due to RI
interference disrupts memory consolidation in AA patients
recollection memories
driven by hippocampus
strong memories
not much change with interference but length of time (delay) makes more of a difference
familiarity
extra hippocampal areas
not strong
delay has little effect but interference makes more difference
can’t prove that a memory doesn’t exist: availability vs accessibility
not all info that is available is accessible
cues improve accessibility
blocking
e.g. tip-of-the-tongue - better identified in recognition task
may reflect insufficient activation of speech output representations from semantic memory - haven’t reached threshold for speech output
misattribution =
sin of commission
source memory confusions
DRM paradigm: over half of pps say they saw lure word earlier - pps reporting recovered/repressed memories more likely to show DRM effect
suggestibility
50% created false memories as result of fake photo of them in hot air balloon
bias
schemas influence episodic memories but not semantic knowledge
(rationalisation errors develop with longer delays)
Bartlett’s war of the ghosts: change content of story to reflect own culture & schemas
lose accurate detail but essence remains
confabulation
patient AKP (amnesia): faulty attmepts to balance the conflicting demands of accurate & self-serving reality representation similar confabulation when recalling stories after one week delay in healthy pps and few mins delay in krsakoff's & Alzheimer's
persistence
hyperthymestic syndrome
