memory and amnesia Flashcards
three main processes of memory
encoding
storage
retrieval
why might our memory fail us (Rs)
they are represented, reconstructed, rebuilt
the testing effect
a long term memory is increased if some of the learning period is spent on retrieval
big increases regardless of age / even seen in dementia patients
how would cognitive neuroscience look at exploring memory problems
functional localisation - functional imaging is used to locate where specific damage is in the brain
how would cognitive psychology look at exploring memory problems
how cognitive models work and how the psychological processes may be damaged
two traditions of human neuropsychology
classical - group study & functional imaging
cognitive neuropsych - single case studies and WHAT the cognitive architecture is, not WHERE
what is the modern version of phrenology
functional specialisation
example of a single case study helping to falsify inductive psych claims
black swans
lucy – remains found of a primate who could walk upright with a SMALL brain
double dissociation
when two related mental processes are shown to function independently
often found using brain damage pairs who are impaired in different tasks & diff brain areas
case study of HM
had temporal lobectomy (= included hippocampus) to treat epilepsy
suffered from both anterograde amnesia and retrograde amnesia
semantic and episodic deficits
anterograde amnesia
decreased ability to retain new information and memories
retrograde amnesia
impaired ability to recall memories that happen before the amnesia
global amnesia
impaired LTM but can carry out STM digit span tasks
what is a double dissociation pair used to distinguish different STM/LTM memory impairments
HM & KF
HM = temporal damage, could carry out STM digit spans but not LTM
KF = parietal lobe damage, normal LTM but impaired on digit span tasks
serial position effect
in free recall, items are recalled most from the start of the list (PRIMACY EFFECT) and the end of the list (RECENCY EFFECT)
how does the double dissociation of KF and HM work with the serial position effect
LTM amnesiacs like HM show no primacy effect
STM amnesiacs like KF show no recency effect
why is defining normality important for memory?
in order to to diagnose pathological memory deficits, we need a comparison to normality
bartlett and memory experiment
one of the first psychologists to define mem as unreliable
war of the ghosts; ppts asked to recall a story – they forgot unfamiliar details and rationalised other parts
change blindness & what this shows
confederate asked random ppts for directions; half way through an obstruction passes and the confederates switch actors; ppt doesnt notice change in actor
=== shows that encoding is mediated by expectations
change blindness - eyewitness testimonies
loftus & palmer car accident study
- when described as ‘smashed’, 32% falsely remembered broken glass
- when ‘hit’, 14% remembered glass
disneyland memory deficit
asked at disneyland exit if they’d shaken hands with bugs bunny; some people said yes; bugs bunny is not a disney character
why is memory often unreliable as an organ
its an organ of representation; used to plan the future rather than exactly record the past
information deficit model
when given myths and facts, people often forget which one was which when they are later tested as the memories merge together
definition of forgetting
a normal function of memory; manifests as errors in retrieval
two theories of forgetting
trace decay theory - the memory trace fades, it is no longer AVAILABLE
interference - some memory traces interfere with the retrieval of others, it is no longer ACCESSIBLE
role of consolidation in remembering/forgetting
consolidation allows memories to move from STM to LTM
study; US football players with concussion could recall events clearly when asked immediately but after 20 mins had completely faded = consolidation was interrupted / impaired
interference study
ppts had to recall info after an interference task or no task at all; all ppts including amnesiacs had much lower recall after interference task
= interference is an integral part of forgetting, even in pathological cases
adaptive reasons for forgetting
brain cannot function without forgetting - patient S could not reason or generalise because memories were too overwhelming
transient epileptic amnesia
seizures cause intense amnesia episodes, within which all other brain function is normal
what is amnesia
memory omissions, intrusions, or inaccessibility
how is alzheimers represented in a brain scan
deterioration of tissue in the hippocampus
amnesia case study LC
intact procedural, general knowledge but severely impaired anterograde LTM - could not remember going to same cafe 3 times in a row with 1 hr between
implicit memory
unconscious/automatic, learned info is retrieved and used without awareness of learning or remembering it
explicit memory
conscious, intentional recollection of episodic or semantic memory
how can the implicit memory system be tested
word completion - filling in gaps to form words
repetition priming - presenting ppt with a question along with a previously presented cue to evoke words related to the cue
implicit / explicit double dissociation
medial temporal lobe amnesia have impaired explicit memory (can’t create new ones) and intact implicit
MS had intact explicit and impaired implicit
what has damage to the hippocampus shown about the specific areas
hippocampal region = episodic mem
parahippocampal region = semantic mem
damage/lesions to ________ causes disorganised memory
prefrontal cortex
what is a key sign of disorganised memory
confabulation; when memory gaps are filled in with fabricated and distorted information
