memory and amnesia Flashcards
the stages of memory process
- encoding
- storage
- retrieval
what is encoding stage
the processing of information into the memory system
what is storage stage
the retention of encoded material over time
what is retrieval stage
the process of getting the information out of memory storage
how is the hippocampus related to memory
it is the main structure for memory (embedded in both temporal lobes)
neurogenesis (plasticity)
cells can regenerate, so the more cells that are generated the harder it is to remember
it explains how we continually reconstruct memories (it cannot be full)
rejects the myth that we only use 10% of our brain
adaptive reasons for forgetting
it is not useful to maintain detailed, veridical information in our memory indefinitely
memories that are retrieved less and less over time become less accessible to allow new more relevant information to take precedence
the loss of access to information through design is not seen as a failure of the system but an adaptive feature that facilitates updating (Bjork, 1978: Roediger III et al., 2010)
it is impossible to live at all without forgetting (Nietzsche)
how do we know memory is unreliable
error in eyewitness testimonies - the brain reconstructs event because it is an organ or re-presentation
different people reconstruct the same event to reflect own experience
what is the information deficit model and how does it relate to memory
relying on imprecise memories leads to the reconstruction of memories as our own narrative
system develops so we can make mistakes which are functional to survival
cognitive offloading
the google effect (Sparrow et al., 2011) - the cognitive consequences of having info at fingertips
people who rely on having information stored elsewhere leads to poorer remembering of information
why does rewatching lectures not benefit learning
watching passively results in poorer learning and rapid forgetting
knowing a lecture is recorded results in cognitive offloading and poorer exam performance
also results in poorer attendance at live lectures
benefits of self testing
if you self test after a lecture, it slows down forgetting (ebbinghaus curve)
recalling what you remember leads to more efficient learning than re-reading or watching
subsequent self testing at various periods after leads to better learning, better and less stressful exam performance and revision takes a lot less time (Thomas et al., 2018)
how to increase memory in the learning period
retrieve the to-be-remembered information
why do expectations influence our perceptions
because we process what we expect to process and we fill in gaps of information with expectations
Frederick Bartlett insight into memory
his central insight was that memory does not faithfully play back our experiences but reconstructs them imaginatively
what are melting memories
memories that mix with what we know from the past
what could go wrong in memory
we could
- not notice
- notice but not encode
- encode but not consolidate
- consolidate but not retrieve
- retrieve but wrongly
- retrieve correctly but forget fast
instances of failures of memories which become pathological after a given level
change blindness (Simons and Levins ,1987)
while participants were distracted doing a task, the actor they were with changed to someone else when they were not looking and went unnoticed by participant
what does change blindness mean for our memory
false information can be misconstrued and believed as fact - demonstrates how malleable memory can be
what are the 2 traditions of human neuropsychology and what approach do they take
what functions are disrupted by damage to region X (classical neuropsychology approach)
can a particular functions be spared/impaired relative to other cognitive functions (cognitive neuropsychological approach)
what questions does the classical neuropsychology approach address and what study methods are typically used
questions of function specialisation, converging evidence to functional imaging
tends to be used in group study methods
what questions does the cognitive neuropsychological approach address and what methods are typically used
questions of what the building blocks of cognition are irrespective of location
tends to be used in single case methodology
phrenology
when different parts of the cortex serve different functions
what is the structure of the neuropsychological assessment (Cubelli and Della Salla, 2011)
interviewing
screening
full blown neuropsychological exams
experimental tests, ad hoc devised or literature derived
what is the interview stage in the neuropsychological assessment
stage 1 - exploring the symptoms
what is the screening stage in the neuropsychological assessment
stage 2 - do a test to identify areas of problems
what is the neuropsychological examination stage in the neuropsychological assessment
stage 3 - reaching a clinical labelling
what is the experimental testing stage in the neuropsychological assessment
stage 4 - making the diagnosing precise
why would we use single cases rather than group study
for real individual data that helps us understand how the mind works instead of an average/pattern performance
what does cognitive neuropsychology states about deficits in the brain and how are these theories derived and used
the deficits that arise as a result of brain damage can be used to explore how the ‘normal’ brain works
theories are derived from models of normal cognitive functions can make precise the questions asked in examination, diagnosis and rehabilitation training of people with cognitive impairments
what are the main questions in neuropsychology from the 2 domians
clinical/classical neuropsychology - what has happened to cause these particular symptoms
answer - the deficits shown are because of damage to a particular area/network/system in the brain (function localisation)
cognitive neuropsychology - what does the pattern of impaired and intact abilities teach us about the way that the ‘normal’ mind and brain work
answer - the deficits shown are because of damage to psychological processes which mediate the impaired functions (cognitive models)
what is HARKing
hypothesising after results are known
double dissociations
when observed, we can assume that the 2 relevant memory systems involve different cognitive systems possible mapped onto different neuronal networks
how do you know if behaviour is normal
we collect data from people who do not have a brain lesion and observe the range of normality
if it falls within the range - normal performance
if it falls outwith the range - abnormal performance
which area of the brain lights up when a face is recognised
the fusiform gyrus
what is apperceptive prosopagnosia
inability to perceive or cognitively process a face
what is associative prosopagnosia
inability to recognise or apply meaning to the face despite being able to perceive the face
what are the 2 paths of facial recognition
emotional processing
cognitive processing
what are causes of amnesia
head injury, stroke, poison, substance abuse, hypoxia (lack of oxygen), AD, drugs, vitamin deficiency, malnutrition, encephalitis (attacks hippocampus/executive functions), alcohol, shock therapy, stress, neurosurgery
- each can result in a deficit of memory but may all be different to each other depending on location in the brain
what is amnesia
acquired impairment of explicit long term memory
- remembering anything must first refer to something which has already been learned
- can impair encoding, retention, and retrieval
anterograde amnesia
when it concerns the period AFTER the onset of the disease (organic or psychogenic)
- describes impaired encoding, retention, or retrieval of episodic memory
difficulty acquiring new memories
retrograde amnesia
when it concerns the period BEFORE the onset of the disease
- describe impaired autobiographic memory
- short term memory and implicit learning and memory are preserved
- other components of long term memory may be spared such as procedural memory, whereas others may be mildly affected, such as semantic memory
difficulty remembering evenst from before the injury
why was global amnesia introduced
to refer to combined verbal and non-verbal memory disorder
- does not refer to severity
what does pure amnesia refer to
the absence of associated cognitive impairments and affects recall and recognition
what happens to the hippocampus when a patient has Alzheimer’s disease
it is very small
short term memory
for information currently in the mind
has limited capacity
long term memory
stored information that need not be presently accessed or even consciously accessible
has virtually unlimited capacity ( all info is in there until it is brought to mind when it enters STM)
what are the two divisions of long term memory
declarative - explicit memory
non declarative - implicit memory
declarative memory
events - specific personal experiences from a particular time and place
facts - world knowledge, object knowledge, language knowledge, and conceptual priming
non declarative memory
procedural memory - motor and cognitive skills
perceptual representation system - perceptual priming
classical conditioning - conditioned responses between two stimuli
non associative learning - habituation sensitisation
why do we need to study patients who have impaired LTM and spared STM and vice versa
to determine the effects on the different functions
e.g. damage to hippocampus impacts LTM
serial positioning effects
in free recall, more items from the start of the list (primacy) and end of the list (recency) are recalled
why are words at the start of a list more likely to be recalled (primacy effect)
because they have entered the long term memory
why are words at the end of the list likely to be recalled (recency effect)
because they are still in our short term memory
how did the serial positioning effect work with patients like HM
recency effect was intact
primacy effect impaired - no encoding benefit
how did the serial positioning effect work with patients like KF
primacy effect intact
recency effect imapired
characteristics of global amnesia (like HM)
have a normal digit span
impaired long term memory
damage to medial temporal lobe
characteristic of patients KF
had a normal long term memory for word lists
impaired digit span
damage to the left parietal lobe
what kind of dissociation did patient KC have after a lesion in right and left hippocampus
a sharp dissociation between intact semantic memory but impaired episodic memory
evidence for KC’s selective retrograde loss
cannot recollect personally experiences events from birth, but knowledge from before the trauma such as maths, history, geography and general knowledge was well preserved
what did it mean for HM to have impaired semantic and episodic memory
semantic - language did not progress, was stuck in 1950s style
episodic - poor at remembering events
what impairment do lesions to hippocampal formation lead to
episodic memory impairment
what impairment do lesions to parahippocampal region lead to
semantic memory imapirment
declarative and non-declarative memory systems - how are these tested for impairment
declarative - tested by recall/recognition
non-declarative - tested by priming tasks
episodic memory characteristics
memory for individual autobiographical experiences and objects that have a contextual tag
semantic memory characteristics
general and conceptual knowledge abstracted from experience
memory of information (general knowledge) with no contextual tag
what is confabulation and how does it occur
false and sometimes self-contradictory memories the patient believes to be true
- associated with damage to a different region than in classical amnesia
occurs following PFC damage (prefrontal conrtex)
what is operant conditioning (positive reinforcement)
when you are unaware of what you are learning
pavlov’s classical conditioning explained
repeated exposure to danger, experiencing some consequence and you learn what to fear
conditioned emotional response leads to emotional state
builds associations which regulates others behaviours
how did Milner at al., (1968) know HM had implicit memory
while amnesiacs will forget when/how they learned, the implicit memory is retained
hm could recognise a drawing as a fish (implicit memory) but forget how he knows it is a fish
patient MS
had intractable epilepsy, surgery removed BA 17, 18 and part of 19
hemianopia (blind in left field)
performed well in a word recognition task compared to amnesiacs
implicit memory
any content of memory that is independent of the modality of learning
information that unintentionally memorised and stored
how do interferences affect memory
forces quicker forgetting
