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"A call to arms" for Computational Cognitive Neuroscience.
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Dr. Brian J. Spieringemail: [email protected]
website: brianspiering.com
The Theory & Practice of
Computational Cognitive Neuroscience
Oblate Spheroid
Oblate Spheroidwith unequal mass distribution
Choose the modelbased on the task
OverviewI) Context
II) Theory
III) Practice
1) ContextA) How to Buy a Science model
B) Validating Models
C) Hierarchy of Models
D) The First Step
What to look for when “buying” a science model ...
1) Accounts for previously accounted for data
2) Accounts for previously unaccounted for data
3) Makes novel, falsifiable predictions
Validating Models
It is easy to account for behavioral data
so add constraints ...
- wider (more tasks)
- deeper (more methodologies)
- neuroscience
Hierarchy of Models
No Model
Modules
Circles & Lines
CCN
Why is CCN on the top?
Can predict in these domains:
- Behavioral
- fMRI
- MEG & EEG
- Single-unit recording
Why is CCN on the top?Can predict account for these factors:
- Experimental Manipulation
- Drugs
- Disease
- Genes
- Focal Lesions (injury, ablation, & TMS)
Where do you start?
Model ➜ Brain
or
Brain ➜ Model
II) Theory of ModelingA) Ideals
B) Modeling individual units
C) Learning
D) Behavior
E) Other Issues
A) Ideals1) Neuroscience
2) Simplicity
3) Set-in-Stone
4) Goodness-of-Fit
1) Neurosciencea) Use only found connections
b) Specify excitatory or inhibitory
c) Account for qualitative behavior in units
d) Agree with neuroscience of learning
2) Simplicity
Use enough but not any more
3) Set-in-Stone
Always use the same players and play by
the same rules in the modeling game.
4) Goodness-of-Fit
a) Behavioral
b) Neuroscience
B) Modeling Units1) Leaky integrate-and-fire model
2) Izhikevich model
3) Axon & synaptic delays
C) Learning1) LTP vs. LTD
2) Role of Dopamine
3) Discrete vs. Continuous
4) Local vs. Global
D) Behavior
1) Choose control region
2) Choose function
E) Other Issues1) Overconnectioning
2) Other?
III) Practice of ModelingSPEED Model:
A) Idea
B) Inception
C) Instantiations
A) SPEED Model IdeaAn Contrarian Model of Procedural Expertise
F. Greg Ashby John Ennis
SPEEDAn Contrarian Model of Procedural Expertise
Previous Notions
“It has been widely held that although memory traces are at first formed in the cerebral cortex, they are finally reduced or transferred by long practice to subcortical levels” (p. 466)
Karl Lashley (1950) In search of the engram.
Previous Notions
“Routine, automatic, or overlearned behavioral sequences, however complex, do not engage the PFC and may be entirely organized in subcortical structures” (p. 323)
Joaquin Fuster (2001). The prefrontal cortex – an update.
SPEEDAn Contrarian Model of Procedural Expertise
SPEED Model
Procedural learning is striatum dependent.
Procedural expertise is striatum independent.
SPEED (Subcortical Pathways Enable Expertise Development)
B) Inception
aka, How we built the model.
SensoryAssociation
Cortex
Response
BA
B
A-B difference
A B
A BA
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:
SensoryAssociationA Response
A
A
AA
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
ExcitatoryInhibitory
SPEED Model:Single Subcortical
SensoryAssociation
Cortex
Response
BA
B
A-B difference
A B
A BA
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:Subcortical
SensoryAssociation
Cortex
StriatumSNpc
Dopamine
Excitatory
SPEED Model:Subcortical Learning
SensoryAssociation
Cortex
Response
BA
B
A-B difference
A B
A BA
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:Subcortical
SensoryAssociation
Cortex
Response
BA
A-B difference
SPEED Model:Cortical
SensoryAssociation
Cortex
Response
BA
B
A-B difference
A B
A BA
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:Cortical Learning
SensoryAssociation
Cortex
A
A
A A
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:1st Trial
SensoryAssociation
Cortex
A
A
A A
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:Early Learning
SensoryAssociation
Cortex
A
A
A A
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:Middle Learning
SensoryAssociation
Cortex
A
A
A A
Premotor Area(Cortex)
Thalamus
Globus PallidusStriatum
SPEED Model:Mature Performance
C) Instantiations
See MATLAB code ...
Summary1) Context
II) Theory
III) Practice
?