Semantic dementia Flashcards
Semantic dementia
Progressive loss of semantic knowledge.
- Doesn’t seem to be anything wrong, but then entire categories/concepts fall away
- Gets worse over time
- Starts with word-finding problems, progresses to losing whole categories/ocncepts
- Difficulty with comprehennsion
- No problem with new learning
The hippo remains intact, but the bilateral damage arises at the infero-lateral temporal cortex (subtype of FT dementia
Typical symptoms
What appears to be semantic knowledge is often episodic
- They remember concepts limited by the active memory they have of it. NO generalization
- Context dependent (toothbrush in the bathroom is recognized, but it the kitchen its not
When asked to draw, distracted and then finish the drawing
- The delayed copy of what they saw (eg camel) turns into weird shit
Picture naming
- More and more specific concepts fall away. First they might recognize ‘bird’, but later just ‘ animal’
Deteriation pattern
The superordinate categories go last,
The subordinates go first
Deteriation is similar to the structure of the quillann’s hierarchical model
high frequency words remain longer than low
