attentional selection through pascal fries - lorentz center fileattentional selection selective...

Leiden, 26 May 2008 F.C. Donders Centre for Cognitive Neuroimaging

Pascal Fries

Attentional selection

selective synchronization.

through


Selective attention implementsselective interactions among neuronal groups.

V4 (“lower” visual area)




PFC

TEO (“higher” visual area)

?

?





PFC


“Higher” (visual) area

“Lower” visual area Time

Fries, TICS, 2005.

The Communication Through Coherence (CTC) hypothesis:

Selective interaction is implemented mechanistically by selective synchronization.


Fries et al., Science, 2001.

Attention enhances local gamma-band synchronization.




20 40 60 80 1000

100

200

300

Frequency (Hz)

Coh

eren

cez

Attended


20 40 60 80 1000

100

200

300

Frequency (Hz)

Coh

eren

cez



Unattended

Attended


Bar touch

Time0 ms-2000 ms 500-5000 ms

Prestimulusinterval

Stimulus interval Responseinterval

Stimulus

The monkey attention paradigm

+ + +

Fixation

Womelsdorf et al., Nature, 2006.

Gamma-band activity in monkey V4 predicts change detection efficiency.

Womelsdorf et al.,Nature, 2006.

+

x10-3

2.6

2.2

1.8

fast

Time (ms)-150-450 150-300 0

RF stim. is attended

Gam

ma

pow

er

slow

Time (ms)

0.18

0.16

0.20

-150-450 150-300 0

Gam

ma

SFC

Time (ms)

0.7

0.5Firin

gra

te

-150-450 150-300 0

0.6

0.4

0.8

-150 150-300 0

+

x10-3 slowfast

2.6

2.2

1.8

-150-450 150-300 0

RF stim. is ignored

0.18

0.16

0.20

-150-450 150-300 0

Time (ms)-150-450 150-300 0

0.7

0.5Firin

gra

teG

amm

apo

wer

Gam

ma

SFC


+ *

Time0 ms-1000 ms 50-3000 ms

Prestimulusinterval

Stimulus interval Responseinterval

Stimulus

The visual MEG paradigm

Hoogenboom et al., Neuroimage, 2005.


The spatial selective tactile delayed matching to sample task.

Bauer et al., JNS, 2006.

A B C D E

The different tactilepatterns used:

Time

D

D A D

EAB

C

C

E

35m

s

1000m

s

500m

s

200m

s500

ms

1000m

s

35m

s

1000m

s

35m

s

1000m

s

35m

s

1000m

s

35m

s

1000m

s

35m

s

1000m

s

35m

s

1000m

s

35m

s

Button

press(both

thumbs)

unattended non-targets

attended non-targets


-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]

Tactile stimulation leads to an increase of gamma-band activity mainly in contralateral S1.


L RL R A P

STI

MR

IGH

TS

TIM

LEFT

t-valuet-value

Gamma-band: Stimulation effect


Attention enhances the somatosensory gamma-increase.

Time rel. to stim. onset [s]

Cum

ulat

ive

Z-sc

ore

0 0.2 0.4 0.6 0.8

0

1

2

Left attended

Right unattended

Left unattended

Right attended


L RL R A P

STI

MR

IGH

TS

TIM

LEFT

t-valuet-value

Gamma-band: Attention effect


+ *

Time0 ms-1000 ms 50-3000 ms

Stimulus interval

Stimulus

Force

Desiredforcelevel

Prestimulusinterval

Responseinterval

The MEG/EMG paradigm

Schoffelen et al., Science, 2005.


0

2.5

5

0 1 2

Haz

ard

rate

(%)

8

6

4

2

0

0 1 2

UP-schedule DOWN-schedule

The hazard rate modulates reaction times.

Time rel. to stim. onset (s) Time rel. to stim. onset (s)


Rea

ctio

ntim

e(m

s)

410

390

370

350

400

380

360


0 1 2

20

40

60

80

Freq

uenc

y(H

z)

-40-200204060Coherence change (%)

Time (s)0 1 2

20

40

60

80

Freq

uenc

y(H

z)

-40-200204060Coherence change (%)

Time (s)


The hazard rate modulatescortico-spinal coherence.



0 1 2-10

0

10

20

30

Time rel. to stim. onset (s)

Gam

ma

-coh

eren

cech

ange

(%)

0

20

40

0 1 2Time rel. to stim. onset (s)


The hazard rate modulates cortico-spinalgamma-band coherence.



20 40 60 80

1

-1

0

Frequency (Hz)

Cro

ssco

rrela

tion

coef

ficie

nt(C

oher

ence

XH

azar

dra

te)

20 40 60 80

1

-1

0

Frequency (Hz)

The hazard rate selectively correlateswith cortico-spinal gamma-coherence.





Time

Towards a direct test of “Communication Through Coherence”.

Womelsdorf et al.,Science, 2007.

0π

0π

“Good” phase relation

“Bad” phase relation

0π


Neuronal interaction depends on neuronal synchronization.

MUA-MUAphaserelations


Time

0.4

0.2

0

0 π−πMUA-MUA Phase relation

MU

A-M

UA

Am

plitu

deco

rrela

tion

0 π−π

Time


Neuronal interaction depends on neuronal synchronization.

MUA - MUAamplitude correlation

Phase relation(0 = “good”)


MUA - LFPamplitude correlation

Phase relation(0 = “good”)


CC (phase relation X amplitude corr.):

Good phase relation precedes strong amplitude correlation.


Peak lag = -5 ms (p < 0.001)


General summary

Gamma-band synchronization is dynamically modulated and predicts behavior.

This suggests an important functional role. Synchronization seems to be one mecha-nism through which cognitive operations like attention control neuronal interactions.

Neuronal synchronization has an mechanistic influence on neuronal interactions.

Groups of neurons influence each other stronger when they are synchronized as com-pared to when they are out of synchrony.

Mechanistically, this is likely due to the fact that rhythmic synchronization within a neu-ronal group implements rhythmic changes in input gain to that group.


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

attentional selection through pascal fries - lorentz center fileattentional selection selective...

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