input single-state dcm intrinsic (within- region) coupling extrinsic (between- region) coupling...
TRANSCRIPT
u
ijij uBA
input
Single-state DCM
1x
Intrinsic (within-region) coupling
Extrinsic (between-region) coupling
NNNN
N
x
x
x
AA
AA
A
CuxuBAx
1
1
111
)(
Multi-state DCM with excitatory and inhibitory connections
Ex1
IN
EN
I
E
AA
AAA
AA
AAA
u
x
x
x
x
x
ee
eee
ee
eee
A
CuxABx
IINN
IENN
EENN
EENNN
IIIE
NEIEE
1
1
00
0
00
0
)(
1
1111
11111
)exp( ijij uBA
Ix1
)exp( 1111IEIE uBA IEx ,
1
The basic approach
Variational free energy
),(
),,(
xgy
uxfx
u
Fmyp
Fyp
qFyp
m
min)|(
min)|(
min)|(,
),()(
))(),((),|(
Np
gNyp
),(
))|(,()|(ln
ln)|,(ln
q
Nq
ypqKLyp
qypF
Minimise free energy
Make inferences
Define likelihood model
Specify priors
Neural dynamics
Observer function
Extrinsicforward
connections
spiny stellate
cells
inhibitory interneurons
pyramidal cells
4 3
236
746
63
225
1205
52
650
214
014
41
278
038
87
2)(
2))()()((
2))()((
2))()((
iii
i
ee
LB
e
e
ee
LF
e
e
ee
LB
e
e
xxxS
Hx
xx
xxxSxSAA
Hx
xx
xxx
xxCuxSIAA
Hx
xx
xxxSIAA
Hx
xx
1 2)( 0xSAF
)( 0xSAL
)( 0xSABExtrinsic backward connections
Intrinsic connections
neuronal (source) model
Extrinsic lateral connections
State equations
,,uxfx
Output equation
0, Lxxg y
A1 A1
STG
ForwardBackward
Lateral
input
Forward and Backward - FB
STG
IFG
2.4
1 (
10
0%
) 4.5
0 (1
00
%) 5
.40
(1
00
%) 1
.74
(96
%)
1.4
1 (
99
%) 0
.93
(55
%)
mode 1
mode 2
mode 3
A1A1
STGSTG
IFG
Changes in extrinsic connections with ‘oddballs’
FFB
lo
g ev
iden
ce Bayesian Model Comparison
subjects
Forward (F)
Backward (B)
Forward and Backward (FB)
Two subgroups