Chapter 18 Flashcards
What part of H. M’s brain was removed?
-bilateral medial-temporal-lobe and part of the hippocampus
Varieties of amnesia
- infantile amnesia
- fugue state
- transient global amnesia
What lobe is most strongly involved in memory?
Temporal lobe
Define amnesia:
The partial or total loss of memory. Umbrella term.
Infantile amnesia
We do not consciously remember our early years of life. Likely due to memory systems maturing at different rates and not being developed.
Fugue state
The temporary repression of the medial temporal love memory system
Transient global amnesia
Acute form of amnesia with a sudden onset and a usually a short course. Loss of old memories and inability to form new.
Possible causes of transient global amnesia
Concussion, migraine, hypoglycemia, epilepsy and stroke
What causes memory loss similar to transient global amnesia
Electroconvulsive therapy
What occurs in Alzheimer’s disease?
Loss of neurons begins in the medial Temporal lobe (resulting in anterograde amnesia) and later damage to the temporal association areas and frontal cortex (related to retrograde amnesia)
Anterograde amnesia
Inability to acquire new memories
Retrograde amnesia
loss of memories that were accessible prior to surgery. Typically presurgical memory is typically much better for events earlier in life
Time dependent retrograde amnesia
Severity of injury determines how far back in time the amnesia extends.
“Islands of Memory”
Isolated events that are retained as memories in retrograde amnesia
What are the three theories of Retrograde Amnesia
Consolidation Theory
Multiple Trace Theory
Reconsolidation Theory
Consolidation theory
The role of the hippocampus is to consolidate new memories and make them permanent. Once consolidation takes place they move elsewhere in the brain. Explains why old memoris are preserved in cases of hippocampal damage
Multiple trace theory
Proposes three kinds of memory:
-Autobiographical memory (personal involvement)
-Factual Semanitic
-General semanitic (unrelated to time or place)
Different types of memory because there are different areas of the brain involved in maintaining memory. Memories change with the passage of time as they are recalled
Why are old memories preserved according to each model?
Consolidation Theory: stored in a different area
Multiple Trace: Recalled, reevaluated and restored more therefore stored in more forms in different locations
Reconsolidation Theory: Many different traces for the same event as it is reconsolidated
According to Multiple trace theory what type of memory is a) language
b) Going to be on this test
c) the memory of studying at thode
a) General semantic
b) Factual Semantic
c) autobiographical
Reconsolidation theory
Proposes that memories will rarely consist of a single trace or neural substrate. Each time a memory is used it is reconsolidated making it a new memory.
What do all the three theories suggest contributes to the temporal gradient of retrograde amnesia
Either:
storage, type of memory or number of times it is used
Where are autobiographical memories located according to Multiple trace theory?
Hippocampus
Where are factual semantic memories located
adjacent TL structures
What are the three different types of memory?
Explicit, Implicit and Emotional
Define Explicit Memory
Conscious intentional, top down process of remembering fact based semantic memories and personal experiences.
What is recall of explicit memory influence by?
How the info was originally processed
Define Implicit Memory
Unconscious, unintentional, bottom up process of remembering. It does not actively use cognitive capacity
Define Emotional Memory
Arousing, vivid and available on prompting. Relies on bottom up processing as well as top down elements. Uses parts of the brain from implicit and explicit memory
What type of memory did H. M have trouble with?
Explicit not implicit. He had a normal learning curve on tasks but couldn’t remember performing them
What type of memory does priming use?
Implicit
Do amnesic subjects perform well on priming tasks?
Yes as well as controls