Semantic memory and the meaning of words - BL3 Flashcards
What are concepts in language?
collections of features
What are the 3 models for concepts in language?
- hierarchically structured
- prototype
- embodied concepts
What do hierarchically structured models of language concepts suggest? (2)
- go from a general category all the way down to the specific thing and information about it
- organisation based on basic level categories and superordinate categories
What is some evidence for hierarchically structured models of language concepts? (2)
- category verification tasks (‘canary is an animal’ vs ‘canary is a bird’ yes or no task)
- reaction times increased as a function of nodes going up the hierarchy
What do hierarchically structured models of language concepts not explain?
why ‘a penguin is a bird’ is slower to respond to than ‘a canary is a bird’ (they are on the same level)
What do prototype models of language concepts suggest?
- concepts are made of frequency/typical features of typical category members
- graded internal structure as a function of similarity to prototype
Which thing do prototype models of language concepts explain that hierarchically structured models of language concepts don’t?
‘penguins are birds’ takes longer than canary because canaries are more prototypical birds
What do embodied concepts theories of language concepts suggest?
- ground concepts in body actions and perception
- think about what you can do with the object as well as what it is
What is some evidence for embodied concepts theories of language concepts?
motor aspects of actions can be activated in the brain when processing language, action verbs in particular
What do distributed models of semantic memory in the brain suggest?
- concepts are a distributed network organised about sensory-motor functions
- networks of features make up categories
- no single meaning centre
According to distributed models of semantic memory in the brain, which 3 things are represented in different areas of the brain when processing language?
motor features, motion features, object and animal shape
Patient JRB can name non-living pictures but not living ones: What might this deficit be explained by? (2)
- damage to category knowledge top node (hierarchical models) - living vs non-living
- selective damage of sensory features (distributed models)
Where is damage in semantic dementia and what does it lead to?
- anterior temporal lobe (mainly the left)
- non-category specific semantic impairments
What view of categories is semantic dementia inconsistent with?
distributed
What other thing can affect the anterior temporal lobe (other than semantic dementia)?
herpes simplex encephalitis
What does semantic dementia lead to a progressive loss of?
low level distinctive features
What are relatively preserved in semantic dementia? (5)
- grammar
- articulation
- episodic memory of events
- spatial and geographical knowledge
- executive control
Which concepts tend to be lost first in semantic dementia? (2)
- low frequency/highly specific concepts
- specific distinctions (use a higher up category for a specific object)
What part of objects seems to be lost first when semantic dementia patients are asked to draw something from memory?
distinctive features
What other factors can affect retention or loss of meanings in semantic dementia? (2)
- familiarity/frequency
- age of acquisition
What does the hub and spoke model suggest?
information flows from the sensory areas of the brain into the anterior temporal pole and back to bring information together
What do semantic processing studies involve?
ask participants to perform meaning-related and conceptual tasks
Which brain regions are involved in semantic competition? (2)
- LIFG
- PMTG
How does brain activation differ in high and low selection conditions when thinking of which word goes with another word?
more competition = more LIFG and PMTG activation
Other than high-selection conditions, what else leads to more LIFG and PMTG activation? (5)
- ambiguity
- more words to choose from
- weakly related words
- verbs > nouns
- abstract > concrete concepts
So what is a summary of the left inferior frontal gyrus? (3)
- involved in retrieving, selecting and maintaining semantic information
- typically acts in concert with PMTG
- convergence zone anatomically
What is semantic control?
meaning processes that are not automatic and require more effort and attention to detail
