Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Pascal Fries
An overview of research
gamma-band synchronization.
on
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma-band synchronization is everywhere
In the LGN
Neuenschwander and Singer, Nature, 1996.
In the retina
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma-band synchronization is everywhere
Maldonado et al., Cerebral Cortex, 2000.
In the primary visual cortex
20 ms
Fries et al., Science, 2001.
In the fourth visual cortex, V4.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma-band synchronization is everywhere
Brosch et al., Journal of Neurophysiology, 2002.
In the primary auditory cortex
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
-0.2 0 0.2 0.4 0.6 0.840
60
80
100
120
140
160
180
-6
-4
-2
0
2
4
6
Cum
ulat
ive
Z-sc
ore
Time rel. to stim. onset [s]
Freq
uenc
y[H
z]
L RL R A P
STI
MR
IGH
TS
TIM
LEFT
t-valuet-value
Gamma-band: Stimulation effect
Gamma-band synchronization is everywhere
Bauer et al., Journal of Neuroscience, 2006.
In the primarysomatosensory cortex
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Am
plitu
de(m
icro
volts
)
Gamma-band synchronization is everywhere
Barrie et al., Journal of Neurophysiology, 1996.
In the olfactory cortex
Aver
age
pow
ersp
ectra
lden
sity
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma-band synchronization is everywhere
Pesaran et al., Nature Neuroscience, 2002.
In the parietal cortex (LIP)
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma-band synchronization is everywhere
Bragin et al., Journal of Neuroscience, 1995.
In the hippocampus
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma-band synchronization is everywhere
Brown et al., Journal of Neurophysiology, 1998.
In the motor system, between motor cortex, spinal cord and muscle
20
40
60
80
100
120
-300
-200
-100
0
100
200
300
Freq
uenc
y[H
z]
Cha
nge
[%of
base
line]
Subject A
Time [s]0 1 2
Hoogenboom et al., Neuroimage, 2005.
Gamma-band synchronization is individual
Cha
nge
[%of
base
line]
-60
-40
-20
0
20
40
60
Subject B Subject C
Cha
nge
[%of
base
line]
-40
-20
0
20
40
-200
-100
0
100
200
20
40
60
80
100
120
-80
-40
0
40
80
-80
-40
0
40
80
Second measurement, same subjects.
Freq
uenc
y[H
z]
Cha
nge
[%of
base
line]
Time [s]0 1 2
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
1 °
RF
1 °
RF
0 50 100 15020
40
60
0 0.1 0.2 0.3 0.4
20
40
60
0 50 100 150
0 0.1 0.2 0.3 0.4
1020304050
0 50 100 150
0 50 100 150
1020304050
Time [ms] Time [ms]
Freq
uenc
y[H
z]
-50-100-150
-50-100-150
-50-100-150
-50-100-150
Coherence Coherence
Freq
uenc
y[H
z]
Supra-granular layers Infra-granular layers
Targ
etch
ange
Dis
tract
erch
ange
Gamma is restricted to the superficial cortical layers.
Buffalo et al., in preparation.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma drives the BOLD signal.
Niessing et al., Science, 2005.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
45
27<
T-value
SAG COR
TRA
A P R L
R L
72±8 Hz
High- and low-frequency gamma-band activity have overlapping sourcesand localize similar to the BOLD signal but different from alpha- and beta-
supressions.
Hoogenboom et al.,Neuroimage,
2005.
11
7<
T-value
SAG COR
TRA
A P R L
R L
42±3 Hz
Linear correlation0.70
0.35
r(977)p < 1.5597e-029
SAG COR
TRA
A P R L
R L
-8
-14
>T-value
SAG COR
TRA
A P R L
R L
25±5 Hz
-11
-18
>
T-value
SAG COR
TRA
A P R L
R L
10±5 Hz
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Pre-Stimulation versus Sustained Stimulation
Sustained Stimulation Pre-Stimulation
Finding Gamma...in LFP, MUA-LFP coherence and MUA-MUA coherence...
Fries et al., Journal of Neuroscience, 2008.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Finding Gamma...is usually easy in LFP/MEG/EEG recordings...
Fries et al., Neuron, 2008.
25
20
T-va
lues
15
20
T-va
lues
120
100
80
60
40
200 1 2
5
0
-5
Time from stimulus onset (s)
Freq
uenc
y(H
z)
Rel
ativ
ech
ange
120
100
80
60
40
200 1 2
0
1
-1
Time from stimulus onset (s)
Freq
uenc
y(H
z)
Rel
ativ
ech
ange
Monkey V1 microelectrode recording
120
100
80
60
40
200 1 2
0
0.4
-0.4
Time from stimulus onset (s)
Freq
uenc
y(H
z)
Rel
ativ
ech
ange
Human MEG recording
Human EEG recording
A
C
E
B
D
F
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Finding Gamma...is usually difficult among single unit recordings...
Zeitler et al., Neural Computation, 2006.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Finding Gamma...is also difficult among simulated single units...
Zeitler et al., Neural Computation, 2006.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Finding gamma...can sometimes depend on the optimal analysis approach.
Fries et al., Journal of Neuroscience, 2008.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Gamma binds!
Gray et al., Nature, 1989.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
a
S yn c
h ron
y(c
orr .co
eff.)
ANOVA: > 0.2P
0.010
0
0.005
0.015
M1
SameDiff.
M2 M3
31 38
28
37
84
17
Ca s
e s
Peak width (ms)
20
15
10
5
005 0 100 150 >150
b
Gamma binds?
Roelfsema et al., Nature Neuroscience, 2004.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Diff.Diff.
Diff.Diff.
SameSame
SameSame
I III
II IV
1
23
1
23
Gamma binds?
Roelfsema et al., Nature Neuroscience, 2004.
0.04
0.04
0.03
0.03
0.02
0.02
0.01
0.01
0
0–0.01
–0.01Corr. coeff. (diff.)
Cor
r .coef
f.(sa
me)
P>0.1
n =59∆ = 0.0006
0 .02
0
10
20
0
–0 .02
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Conclusions:Gamma is a fundamental emergent property of activated neuronal networks.
It can be observed at many different levels of neuronal recordings. With spike-spikecoherence, optimized analysis techniques can be crucial.
Gamma-band synchronization binds neuronal representations of items that are per-ceptually grouped.
Gamma-band synchronization is modulated by a (low) theta rhythm.
In the visual system, a 3.3 Hz rhythm modulates microsaccades, and thereby gamma-band synchronization and reaction times.
Let’s investigate in my talk tomorrow how gamma might be useful for controlling com-munication in the brain.
Leiden, 27 May 2008 F.C. Donders Centre for Cognitive Neuroimaging
Links: The data analysis software is available in the FieldTrip open source Matlab tool-box: www.ru.nl/fcdonders/fieldtrip.
Positions:Three postdoctoral positions and one PhD position are open in my lab.Details at: www.ru.nl/fcdonders.
Jan-MathijsSchoffelen
ThiloWomelsdorf
WolfSinger(MPI)
BobDesimone(MIT)
RobertOostenveld
Gijs vanElswijk
Thanks to:
NienkeHoogenboom
FemkeMaijDick
Stegemann
ConradoBosman
MarkusBauer