Speaker: Tony Tseng, Jimmy Lu Topics: Exploring Complex Networks Date: 2010.05.29 WECO Lab, CSIE, FJU

1. Brian Simulator
(a draft)
Speaker : Tony Tseng, Jimmy Lu
Advisor : Hsing Mei
Web Computing Laboratory(WECO Lab)
Computer Science and Information Engineering Department
Fu Jen Catholic University

2. Outline
 Graph Theoretical Analysis in AD
 Disconnection Syndrome
 Brain Simulator—a draft
 Purpose
 Basic structure
 Brain features
 Proposed brain simulator
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3. Graph Theoretical
Analysis in AD
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4. Introduction
 AD as a Disconnection Syndrome
 Two problems need further attention
 Assessment of functional connectivity with EEG
and MEG can be biased by volume conduction
 Lack a framework to discriminate between
normal and abnormal networks in the brain
 Today’s talk will focus on the theoretical
framework
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5. Graph Analysis
 Brain disease or aging gives rise to a
deviation from the small world
configuration of brain network
 Weighted graph reflects
the strength of the relation
between two vertices.
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6. Network Damage Models
 The Random Failure Model
 Network changes are due to a random decrease
in strength of edges
 The Targeted Attack Model
 Edges connecting hubs will be more vulnerable
to attack
 Our proposed Model
 Aging Model
 Disease-specific network change model
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7. Damage modeling procedure
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8. Result analysis - weighted MEG graphs
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9. Result analysis - Comparison of normalized weighted clustering coefficient (left
panel) and path length (right panel)
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10. Disconnection
Syndrome
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11. Disconnection Syndrome
 The classical associationist era
 Karl Wernicke’s school: associationism
 Fundamental psychic elements or memory
images
 Higher functions were not localized in specific
regions but were the result of associative
connections between motor and sensory
memory image area
 No cortical specializations
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12. The Classical Disconnection Syndrome
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13. Disconnection Syndrome
 Geschwind’s neo-associationism
 Shift away from pure holism
 Flechsig’s rule: association cortex acted, in
effect, as an obligatory relay between different
brain regions and that a lesion to it would serve
to disconnect them
 A comparative phylogenetic perspective to the
development of associations
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14. Geschwind’s view of the evolution of cross-modality associations
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15. Geschwind’s disconnection syndromes
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16. Disconnection Syndrome
 Disconnection syndromes after Geschwind
 Weakness of Geschwind’s theory
 Extended territories composed of many specialized
cortical subregions serving different but related
functions
 Feed-back and parallel pathways
 Hodotopic framwork
 Topological mechanism (place)
 Hodological mechanism (road or path)
 Hyperconnection and cortical hyperfunction
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17. A hodotopic framwork for clinicopathological correlations
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18. Brain simulator
(a draft)
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2010/5/28 18
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19. What is the purpose?
 Short term: Provide an information about
how the Alzheimer’s disease effects brain
structural and functional connectivity
 Medium term: extend the models to brain
diseases
 Long term: whole brain models including
sleep
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20. It is based on...
 Three types of brain network (structure)
 Neural Darwin selection (development)
 Hodotopic framwork (syndrome/function)
 Default-mode network/resting state (state)
 Four stage of Alzheimer’s disease (time)
 Hypothesis of Alzheimer’s disease
 Damage model (topology)
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21. Selection of brain features
 Self-organized
 Degeneracy
 Parallel distributed processing (PDP)
 Small-world, scale free, random topology
 Feed forward and back
 Reconfigurations toward damages
 Balance and Dynamics
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22. How does it work?
fMRI
EEG/
MEG
psycho- Proposed Brain
metrics Simulator
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23. Thalamo- Polysynaptic Diffuse
cortical motif loop structure ascending Space
projections
Network Development Model
Developmental Experiential Reentrant
Selection Selection Mapping
Time
Network Aging Network
Model Damage Model
Decision Making Model Balance
&
Dynamics
Proposed brain simulator
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2010/5/28 23
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24. Reference
 [1] C. J. Stam, W. de Haan, A. Daffertshofer, B. F. Jones, I. Manshanden,
A. M. van Cappellen van Walsum, T. Montez, J. P. A. Verbunt, J. C. de
Munck, B. W. van Dijk, H. W. Berendse and P. Scheltens, “Graph
theoretical analysis of magnetoencephalographic functional
connectivity in Alzheimer’s disease”, Brain 2009: 132; 213–224
 [2] Marco Catani, Dominic H. ffytche, “The rises and falls of
disconnection syndromes”, Brain 2005: 128, 2224–2239
 [3] “Alzheimer's disease ”, Wikipedia
http://en.wikipedia.org/wiki/Alzheimer's_disease
 [4] Gerald M. Edelman, “Wider than the Sky: The Phenomenal Gift of
Consciousness”, Yale University Press (March 10, 2004)
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