Lecture 20 - Amnesia Flashcards
(43 cards)
What is anterograde amnesia?
Inability to encode, store, or retrieve new information for future use
What is retrograde amnesia?
Inability to access information or events that happened in the past
Which type of memory is affceted in anterograde amnesia?
Future-orientated memory (new learning)
Which type of memory is affceted in retrograde amnesia?
Past-orientated memory (pre-existing events)
Name 4 common causes of amnesia
1) Alzheimer’s Disease (AD)
2) Korsakoff Syndrome
3) Herpes Simplex Encephalitis
4) Temporal lobe surgery
Why is Alzheimer’s not considered a pure amnesia?
It also involves other cognitive impairments associated with dementia
What causes Korsakoff Syndrome, and what characterises it?
- Chronic alcoholism
- Characterised mainly by memory impairment
Who is Clive Wearing, and what caused his amnesia?
A musician with severe amnesia due to Herpes Simplex Encephalitis
What part of the brain was removed in H.M’s surgery?
Medial temporal lobe (MTL), including the hippocampus
What was the result of H.M.’s surgery?
Seizures stopped, but he developed profound anterograde amnesia and some retrograde amnesia
How far back did H.m>’s retrograde amnesia extend?
Up to 11 years before the surgery (age 16)
What types of memory were preserved in H.M.?
STM, procedural memory, and some implicit memory
What did Baddeley & Warrington (1970) find about STM in amnesic?
STM (e.g., digit span) was intact
What task showed preserved procedural memory in H.M.?
- Mirror drawing (Corkin, 1968)
- Mirror reading (Cohen & Squire, 1980)
What is implicit memory?
Influence of past experience on behaviour without conscious awareness
What did Claparede (1911) show about implicit memory?
A patient refused to shake his hand after being pricked previously, despite not remembering the event, showing implicit memory
What did Warrington & Weiskrantz (1968) find using degraded images?
Amnesic patients showed marked improvement in identifying degraded pictures/words over time, despite not recalling having seen them, showing preserved implicit memory
How did H.M perform in implicit memory tasks like those in MIlner et al. (1968)?
Like other amnesics, H.M. improved on tasks over time despite no conscious recollection, showing intact implicit memory
What did Graf et al. (1984) find about implicit vs explicit memory in amnesia?
Amnesics performed poorly on explicit recall tasks but showed normal performance in implicit word-stem completion tasks
What types of tasks typically assess episodic memory?
Free recall or recognition tasks
According to dual-process models, what are the two bases for memory performance?
1) Recollection (detailed, conscious recall)
2) Familiarity (feeling of knowing without details)
What did the Doors and People test (Baddeley et al., 2001) reveal about Jon?
- Jon had much lower recall than controls, especially for visual info
- Jon’s recognition performance was slightly better but still below controls
What difficulty did Jon have with the Remember/Know (R/K) distinction?
Though he used R/K terms like controls, he couldn’t explain his “remember” responses and relied on strength of familiarity instead
What did Duzel et al. (2001) find about Jon’s memory in ERP studies?
Jon lacked a normal ERP signature for “remember” responses, indicating impaired recollection
