Intro Takin scann proba betw direc regio cingu Meth The s More The

The Basa
al Ganglia Cou
upling during
g Social Interaaction Revealeed by Dyadic ffMRI
1
Ray Lee1
Neurosciencee Institute, Princetton University, Priinceton, NJ, Uniteed States
Introoduction
Takinng advantage of emerging dyadic fMRII (dfMRI) (1), a study on tw
wo human-brrain interactioons inside onee MRI
scannner was condu
ucted. Besidees confirmed most
m of the prrevious resultts regarding B
BOLD effect in social cognnition, the
probaabilistic indep
pendent comp
ponent analyssis (PICA) (2)) results of ouur dfMRI dataa reveal that tthe basal gangglia coupling
betw
ween two brain
ns could be an
n essential staage in social cognition,
c
as ssuggested in R
Ref. (3). Thiss is the first tiime that fMRII
direcctly shows thaat a special region of brain becomes cou
upled during ssocial interacttion, while m
most other BOLD active
regioons due to soccial cognition, such as med
dial prefrontall cortex (fPFC
C), temporal pparietal junctiion (TPJ), or posterior
cinguulate cortex (P
PCC), are on
nly coherent within
w
each in
ndividual brainn.
Meth
hod
The sstudy was con
nducted with a custom-maade dual-head coil system oon a Siemens 3T Skyra scaanner, as show
wn in Fig. 1.
Moree than 20 dfM
MRI studies were
w
conducteed with subject-pairs lyingg on their sidees, face-to-facce, inside thee magnet boree.
The ppulse sequence used for the
t functionall studies is EPI with TR 22000ms, TE 30ms, FOV 5500mm×250m
mm, sampling
g
matriix 128×64, slice thickness 4mm, voxel size 4mm×4m
mm×4mm, annd flip angle 80°. The fielld map is acquuired by GRE
E
sequeence with thee same resolu
ution and slices as in the functional
f
EP
PI sequence. T
The anatomiccal images arre acquired by
y
MPR
RAGE sequen
nce with vox
xel size 2mm
m×2mm×2mm
m. Each run has 200 meeasurements in which the subject-paiir
perioodically open and close theeir eyes, eitheer simultaneou
usly or alternaately. Each peeriod has 20 m
m
measurementts; ten of them
are dduring open ey
ye intervals and
a another teen are during closed eye inntervals. The functional daata was post-pprocessed with
h
softw
ware package FSL (Oxford University, UK).
U
Resu
ults
All ddata sets were post-processsed with both GLM and PIC
CA with thre shold Z=3.0 aand P=0.05, hhigh pass filteer cutoff=90s
M. However
and sspatial smooth
hing FWHM=
=5mm. Fig. 2 shows BOLD
D activation dduring mutuaal gazing calcuulated by GLM
the activation at PCC
P
in right and
a TPJ in left
ft person are not
n correlatedd at all. Fig. 3 is the same ddata set but prrocessed with
h
PICA
A. Both basal ganglia from
m both subjects are clearly coupled
c
into oone componeent, which hass 1.52% of exxplained
variaance and 1.03% of total varriance. Note that
t among alll 52 componeents, this is onne of a few inn which both brains are
coupled.
Fig. 1
Fig. 1
Fiig. 3
Concclusions
T
The dfMRI op
pens up a new
w field of stud
dying human brain
b
interactiion directly aand quantitativvely. Its first significant
resullt suggests thaat the basal gaanglia, especiially caudate nucleus,
n
coul d be in couplled mode duriing social inteeraction.
Given the role of the
t basal gang
glia in impliccit learning, qu
uantifying suuch coupling ccould be essenntial for both social
nd diagnosis of
o autism.
cognnition study an
Referrences
1.
Lee RF, et al. A Twin-Heead Coil for Stu
udying Two Brain Interactionn with fMRI. P
Proceeding of IInternation Socciety of
Magnetic Resonance
R
in Medicine
M
18th Annual Meetin
ng. Stockholm,, Sweden; 20100. p 1513.
2.
Beckmann
n CF, Smith SM
M. Probabilisticc Independent Component
C
Annalysis for Funnctional Magneetic Resonancee Imaging.
IEEE transs on Medical Im
maging 2004;2
23(2):137.
3.
Lieberman
n MD. Intuition
n: A Social Cog
gnitive Neurosscience Approaach. Psychologgical Bulletin 22000;126(1):1009.
Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
2897