Amnesia Flashcards
Description of memory
It’s dynamic and malleable, complex in structure and it’s only really noticeable when it doesn’t work
Disorders that affect memory
- Dementia
- Toxic conditions
- Anoxia or hypoxia
- Head injuries
Cookie metaphor for memory
A whole chocolate chip cookie that you crumble over the brain, you can piece it back together from the different places, but you’re never going to have the fixed whole again
Two streams of episodic memory
Autobiographical vs non autobiographical
Define anterograde amnesia
Loss of the ability to encode and learn new information after a defined event
Define retrograde amnesia
The loss of old memories from before a defined event
Explain the case of NA
He had a small lesion in the left dorsomedial nucleus of the thalamus, with complete anterograde amnesia and retrograde amnesia stretching back 2 years before the accident
Three components of conceptual memory system
- Sensory memory
- Short term memory
- Long term memory
Stats for sensory memory
Duration: milliseconds
Capacity: practically unlimited
Stats for short term memory
Duration: seconds, unless info is rehearsed
Capacity: 7 (+- 2) bits
Stats for long term memory
Duration: relatively permanent
Capacity: practically unlimited
Declarative vs non declarative memory
Declarative: accessible to conscious awareness
Non-declarative: demonstrated by performance and generally not accessible to conscious awareness
Explicit vs implicit memory tasks
Explicit: recall or recognition
Implicit: priming tasks
How are memories stored?
Where they are first processed
Description of the functional model of declarative memory
Function: to process info to consolidate it fr storage
New declarative learning occurs –> info filters into neural areas responsible for declarative memory processing –> return pathways take info back to specific cortical areas
Encoding and retrieval laterlization
Episodic encoding (verbal) - left PFC
Episodic encoding (non verbal) - bilateral and right PFC
Episodic retrieval - right hemisphere PFC
Semantic retrieval - left hemisphere PFC
Function and anatomy of consolidation in the medial temporal lobe
It moves new information into storage
It’s centred around the hippocampus, including dentate gyrus and subiculum, as well as adjacent perirhinal, entorhinal and parahippocampal cortices
Anatomy involved in the diencephalon’s role in consolidation of declarative memory
- Specific nuclei of the thalamus
2. Mammillary bodies of the hypothalamus
What happens when there is damage to the dorsal medial thalamic nuclei?
Korsakoff’s disease and cases of special amnesia. There is also mammillary body damage in Korsakoffs.
Which structures of the basal forebrain are used in consolidating declarative memory?
- Nucleus basalis of Meynert
- Medial septal nucleus
- Nucleus of the diagonal band of Broca’s
- Substantia innominata
