transcript
- Slide 1
- Slide 2
- Putting the Pieces Together: Concept Acquisition and Semantic
Feature Integration Jamie Reilly, Ph.D. Cognition and Language
Laboratory University of Florida jjreilly@phhp.ufl.edu
- Slide 3
- Roadmap for Todays Talk What is semantic memory? Neural
instantiation of semantic memory Competing Theories An overarching
framework Neuropsychological impairment Frontotemporal Dementia,
Alzheimers Disease A different approach to semantic organization
Preliminary evidence from fMRI
- Slide 4
- Semantic Memory Tulving (1972) Semantic memory is the memory
necessary for the use of language. It is a mental thesaurus,
organized knowledge a person possesses about words, their meaning
and referents, about relations among them and about algorithms for
the manipulation of these symbols, concepts and relations. lab
Domesticated Mammal friendly Chase cats
- Slide 5
- Neural Representation of Semantic Memory: Fully Distributed
Theories Object knowledge grounded in perception Feature
decomposition (Freud, 1890; Lissauer, 1892) No CENTRAL organizing
brain region Feature woof color motion visual form tactile Dog =
Co-Activation
- Slide 6
- Neural Representation of Semantic Memory II: Distributed + Hub
Theory (Patterson, 2008) Semantic memory is amodal Features are
bound by anterior temporal cortex woof color motion visual form
tactile Feature Binding
- Slide 7
- A Useful Framework for Understanding Semantic Memory Semantic
memory is a dynamic system Process versus Content Library (feature
storage) and librarian (retrieval) Process: Progressive Nonfluent
Aphasia Content: Semantic Dementia Content and Process: Alzheimers
Disease
- Slide 8
- Semantic Dementia Warrington (1975) Selective impairment of
semantic memory Temporal lobe variant of Frontotemporal Dementia
(Snowden et al., 1988; Neary et al., 1998)
- Slide 9
- Core Diagnostic Criteria for Semantic Dementia (Neary et al.,
1998) Insidious onset Prosopagnosia and/or Associative Agnosia Loss
of word meaning Semantic paraphasias (e.g., ball for apple)
Preserved perceptual matching Preserved single word repetition
Fluent + Empty Spontaneous Speech Asymmetric onset
(Left>Right)
- Slide 10
- Semantic Dementia Lateral Cortical Atrophy Mild (n=4) Moderate
(n=5) Processing of Object Form Phonological and Lexical Processing
Gray matter atrophy (p
- Alzheimers Disease Diagnostic Criteria (NINCDS-ADRA, 1984) Core
Symptoms Dementia Onset between 40 and 90 years Deficits in >2
areas of cognition Progressive memory impairment Preserved
Consciousness No concurrent systemic impairment Supportive Features
Anomia Visuospatial impairment Visual agnosia Altered behavior /
Diminished ADLs Family history Serial observation of cerebral
atrophy
- Slide 21
- Alzheimers Disease: Process and Content Boston Naming Test
(Kaplan, Goodglass & Weintraub, 1983)
- Slide 22
- Naming Accuracy Semantic Dementia, Alzheimers Disease, PNFA
Groups ns different by oneway ANOVA (p>.05) but the devil is in
the details ADn=36 SDn=21 PNFAn=12
- Slide 23
- Behavioral Results Proportion of Semantic Relative to Other
Errors
- Slide 24
- Semantic Error Differences Group x Semantic Error Interaction:
F(5.28, 245)=3.82, p
- Preliminary Naming Results: Auditory > ELSE
- Slide 33
- Preliminary Naming Results: VISUAL > ELSE
- Slide 34
- Preliminary Naming Results: Point Light Motion > ELSE
- Slide 35
- Preliminary Naming Results: Conjunction Analysis
- Slide 36
- Concluding Remarks We have much to learn about the neural
substrates of semantic memory Active debate in cognitive
neuroscience Imaging and neuropsychology Many disparate findings to
reconcile e.g., how to image the anterior temporal lobe? A deeper
understanding of semantic representation is critical toward
providing an informed basis for the treatment of communicative
disorders aphasia and dementia
- Slide 37
- Bruce Crosson Leslie Gonzalez-Rothi Kenneth Heilman Murray
Grossman Nadine Martin Steve Nadeau Cognition and Language Lab on
the Web: Supported by US Public Health Service Grants:
R01-DC001924, K23-DC010197 Acknowledgements
http://phhp.ufl.edu/~jjreilly