T1 L10 Neuropsychology of memory Flashcards
What is amnesia?
Intelligence is intact
Attentional span is intact
Personality is unaffected
Ability to take in new information is severely & usually permanently affected
Verbal & visual short-term memory is intact
What happened to HM?
Underwent surgery for treatment of severe epilepsy
Surgery involved bilateral removal of his medial temporal lobes including the hippocampus
Completely lost his memory for events after surgery
What is amnesia usually caused by?
Damage to the medial temporal lobe or anatomically connected regions
What conditions can amnesia occur in?
Head injurys
Alzheimer’s disease
Epilepsy
Stroke
What is anterograde amnesia?
After the brain injury
Anterograde episodic memories are severely affected
What is procedural memory?
Learning of motor skills, which is distinct from explicit long-term memory
What is the evidence that amnesiacs can learn new skills?
Mirror tracing - Corkin (1968)
Mirror reading - Cohen & Squire (1980)
What were the results of Butters study in 1990?
Healthy controls & patients with Alzheimer’s disease showed normal learning (implicit memory)
Patients with Huntingdon’s disease were impaired
Evidence for independent procedural memory system
What are the dedicated brain systems for procedural memory?
Basal ganglia
What happens when a skill becomes automatic?
It can operate in the absence of awareness
What is the declarative memory theory?
All declarative memories (episodic & semantic) depend on medial temporal lobes for their acquisition & short-term retention
Describe Tulving’s definitions in 1971
Episodic memory - Memory for events & occurrences that are specific in time & place
Semantic memory - knowledge of facts, concepts, word meanings. Can be retrieved without knowledge about where & when information was acquired
According to Bayley in 2008, can new semantic memories be formed despite amnesia?
No
Tested new vocabulary in 2 adult amnesiacs
Poor episodic & semantic memory
Supports Squire’s declarative memory theory
Can new semantic memories be formed despite amnesia when testing patients with damage after birth?
3 typical amnesiacs who had damage to the hippocampus just after birth
Have grossly impaired episodic memory
They can form new semantic memories
What did Sharon test in 2011?
New learning in adult amnesiacs
When learning was incidental, amnesiacs could learn the names of objects
New semantic memories can be formed
Doesn’t support Squire’s declarative memory theory
What is retrograde amnesia?
Before brain injury
Some degree is almost always present
What is the standard model of consolidation?
Over time, declarative memories become consolidated to other brain regions
What are the retrograde (long-before lesion) memories affected in a typical amnesiac patient?
Episodic - okay
Semantic - okay
Supports Squire’s standard model of consolidation
?What did Viskontas do in 2000
Tested 25 patients with unilateral temporal lobe epilepsy
Found poor episodic memory & okay semantic memory
Doesn’t support Squire’s standard model of consolidation
Describe impairment of semantic memory
Semantic dementia
Poor knowledge of meaning of words or concepts
Naming difficulties
Not confined to one modality
What is semantic knowledge associated with?
The lateral temporal cortex on the left side of the brain
What did Janowsky investigate in 1989?
7 patients with frontal lobe lesions Learned 20 trivial facts 6-8 day interval Tested 40 questions Patients were only impaired on their ability to identify where they had learnt the information
What are the types of confabulation?
Erroneous memories
Provoked
Spontaneous
Describe provoked confabulation?
Normal response to a demand for information which is not available
What is erroneous memories confabulation?
Memories either false in themselves or resulting from true memories misplaced in context or inappropriately retrieved or interpreted
What is spontaneous confabulation?
Person acts on their erroneous memories
Usually a result of frontal lobe damage
Not due to a damage to memory storage
What causes spontaneous confabulation?
Breakdown in memory by control processes such as monitoring whether retrieved memories are relevant to now
