Disorders of Memory Flashcards
What are the 2 primary types of amnesia?
- retrograde amnesia (forgets past memories from before amnesia, can make new memories)
- anterograde amnesia (cannot form new memories after amnesia, remember past)
What brain structures were removed from patient HM’s brain?
medial temporal lobes: hippocampus, amygdala, and nearby cortex (highly connected to hippocampus)
What was patient HM’s performance on short-term & long-term memory tasks?
short-term/working memory intact
impairment in long-term memory
therefore, 2 types of memory supported by different brain mechanisms
Recall the diagram of the 3 forms of memory & state how information is lost from each.
sensory input -> SENSORY MEMORY -> attention -> SHORT-TERM MEMORY -> encoding -> LONG-TERM MEMORY
sensory = unattended
short-term = unrehearsed
long-term = over time
What are the divisions of long-term memory?
- explicit memory (requires conscious awareness)
- implicit memory (does not require conscious awareness)
What are the subtypes of EXPLICIT memory?
- Semantic Memory (facts & general knowledge)
- Episodic Memory (personally experienced events)
What are the subtypes of IMPLICIT memory?
- Procedural Memory (motor & cognitive skills)
- Priming (enhanced identification of objects/words)
- Learning through classical conditioning
What is the role of the hippocampus in memory consolidation?
- hippocampus temporarily stores and links new memories
- repeated reactivation strengthens memory connections in the cortex, making them independent of the hippocampus
- consolidated memories stored in neocortex and can recalled without hippocampal involvement (sleep helps reinforce)
What is a difference in the memory performance of patient HM & patient KC?
patient KC experienced anterograde amnesia following motorcycle accident –> could not form memories for personal events
BUT could learn new information such as famous names & internet terms (=preserved semantic memory)
What is Korsakoff’s Syndrome?
result of brain damage due to vitamin B1 deficiency, often linked to heavy alcohol consumption
symptoms: confusion, abnormal eye movements, hypothermia, coordination problems, coma
What are the degree of amnesia in korsakoff syndrome?
severe anterograde amnesia & mild retrograde amnesia (limited to explicit memory)
often confabulate (“honest lying”) = inaccurate stories abt events
What are the damaged structures & treatment for Korsakoff Syndrome?
damaged structures: thalamus & hippocampus (medial diencephalic structures) & diffuse damage to cortex, hippocampus, cerebellum
treatment: thiamine supplements & nutrition, address alcohol use if relevant
