LECTURE 4-MEMORY DISORDERS Flashcards
What causes poor episodic memory
damage to the hippocampus
what causes poor semantic memory
damage to the para hippocampal cortex
what is retrograde amnesia
Poor recall/accessing for memories formed before onset of amnesia, normally you will have poorer episodic memory. Older memories are less impaired than newer memories. There are 3 explinations for this
- consolidation theory- consolidated memories are stored elsewhere , protecting them from effects of hippocampal damage
- semanticisation= episodic memories become more semantic meaning they are stored elsewhere and so are protected.
- reduced learning opportunity= episodic require a single learned experience but semantic rely on several. older memories have more recall so more robust memory.
What is anterograde amnesia
Loss of ability to form new memories after onset of amnesia
what is global amnesia
poor memory for both before and after - results in lesions in the medial temporal lobe (hippocampus).
severe anterograde , mild retrograde
What is Korsakoff’s syndrome?
Also known as diencephalic amnesia- Due to vitamin B1 deficiency because of chronic alcoholism damaging mammillary bodies in the hyper thalamus.
symptoms= memory impairment, before and after. impairment of STM
what is semantic dementia
severe issues with semantic memory but intact episodic memory. loss of info of meaning of words, concepts, naming pictures, objects.
cause= degeneration of the anterior temporal lobe where semantic memories are stored.
points to a double dissociation= identify that brain damage to one structure distrupts one cognitive process (x) but not another (y)/ also identify that brain damage to different structure disrupts cognitive process y but not x e.g. amnesia and semantic dementia
memory errors= forgetting
easier to remember recent events as we forget due to decay. Memory traces fade over time so less info available for retrieval as time goes on.
can be caused by interference- when similar info can interfere this can be retroactive or proactive.
memory errors- intrusions
mistakes in which elements not part of original memory get mixed up or intrude recall due to associations we make.
associated with DRM paradigm- we recall words semantically associated with a list that weren’t actually on the list
misinformation effect= memories distorted by misleading info given after.
source misattribution= a memory probe activates memory traces with overlapping info- memories from one source resemble those from another.
memory errors- BIAS
memories influenced by prior expectations
conformation bias- tendency to recall info that confirms our re existing beliefs
face recognition= prone to error due to
unconscious transference (misidentify a familiar but innocent face as being responsible)
other race effect (recognition for same race faces generally more accurate than other races)
own age bias (more accurate when culprit is similar age to witness)
KEY STUDY- LOFTUS AND PALMER-
PPTS shown a film of a car accident
Asked how fast the cars were going when they smashed (estimated 42 mph)/hit (estimated 34 mph)
One week later they asked recall later saying ‘did you see any broken glass’ (there was no actual glass)- those who asked smashed said 34% yes there was glass. Those who heard hit 14% said yes
KEY STUDY- TUCKEY AND BREWER
Ppts shown film of stimulated bank robbery- recalled info relevant to bank robber schema e.g. robber was male wearing disguise and demanded money/ less likely to recall info irrelevant to schema e.g. colour of getaway car
how can we avoid memory erros?
Cognitive interview- strategies to aid mental interview- stages include- 1= mental reinstatement of the environment, 2= encouraged to report every detail, 3=describe the incident in several different orders, 4= reporting from different view point (works via encoding specificity principle for 1, 2 and different retrieval routes for 3,4)
