Research Square (Research Square),
Год журнала:
2022,
Номер
unknown
Опубликована: Авг. 3, 2022
Abstract
Recent
studies
have
shown
that
functional
connectivity
can
be
decomposed
into
its
exact
framewise
contributions,
revealing
short-lived,
infrequent,
and
high-amplitude
time
points
referred
to
as
``events.''
Although
events
contribute
disproportionately
the
time-averaged
pattern,
improve
identifiability
brain-behavior
associations,
been
linked
endogenous
hormonal
fluctuations
autism,
their
origins
remain
unclear.
Here,
we
address
this
question
using
two
independently-acquired
imaging
datasets
in
which
participants
passively
watched
movies.
We
find
synchronize
across
individuals
based
on
level
of
synchronization,
categorized
three
distinct
classes:
those
at
boundaries
between
movies,
during
do
not
all.
boundary
events,
compared
other
categories,
exhibit
greater
amplitude,
co-fluctuation
patterns,
temporal
propagation.
show
underlying
is
a
specific
mode
involving
activation
control
salience
systems
alongside
deactivation
visual
systems.
Finally,
strong
positive
relationship
similarity
time-locked
patterns
propensity
for
frames
involve
synchronous
events.
Collectively,
our
results
suggest
spatiotemporal
properties
are
non-random
locked
time-varying
stimuli.
Proceedings of the National Academy of Sciences,
Год журнала:
2023,
Номер
120(30)
Опубликована: Июль 19, 2023
The
standard
approach
to
modeling
the
human
brain
as
a
complex
system
is
with
network,
where
basic
unit
of
interaction
pairwise
link
between
two
regions.
While
powerful,
this
limited
by
inability
assess
higher-order
interactions
involving
three
or
more
elements
directly.
In
work,
we
explore
method
for
capturing
dependencies
in
multivariate
data:
partial
entropy
decomposition
(PED).
Our
decomposes
joint
whole
into
set
nonnegative
atoms
that
describe
redundant,
unique,
and
synergistic
compose
system's
structure.
PED
gives
insight
mathematics
functional
connectivity
its
limitation.
When
applied
resting-state
fMRI
data,
find
robust
evidence
synergies
are
largely
invisible
analyses.
can
also
be
localized
time,
allowing
frame-by-frame
analysis
how
distributions
redundancies
change
over
course
recording.
We
different
ensembles
regions
transiently
from
being
redundancy-dominated
synergy-dominated
temporal
pattern
structured
time.
These
results
provide
strong
there
exists
large
space
unexplored
structures
data
have
been
missed
focus
on
bivariate
network
models.
This
structure
dynamic
time
likely
will
illuminate
interesting
links
behavior.
Beyond
brain-specific
application,
provides
very
general
understanding
variety
systems.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Фев. 8, 2024
Abstract
Brain
dynamic
functional
connectivity
characterises
transient
connections
between
brain
regions.
Features
of
dynamics
have
been
linked
to
emotion
and
cognition
in
adult
individuals,
atypical
patterns
associated
with
neurodevelopmental
conditions
such
as
autism.
Although
reliable
networks
consistently
identified
neonates,
little
is
known
about
the
early
development
connectivity.
In
this
study
we
characterise
magnetic
resonance
imaging
(fMRI)
first
few
weeks
postnatal
life
term-born
(
n
=
324)
preterm-born
66)
individuals.
We
show
that
a
landscape
already
established
by
time
birth
human
brain,
characterised
six
states
neonatal
changing
through
period.
The
pattern
infants,
social,
sensory,
repetitive
behaviours
measured
Quantitative
Checklist
for
Autism
Toddlers
(Q-CHAT)
scores
at
18
months
age.
NeuroImage,
Год журнала:
2022,
Номер
252, С. 118993 - 118993
Опубликована: Фев. 19, 2022
Resting-state
functional
connectivity
is
typically
modeled
as
the
correlation
structure
of
whole-brain
regional
activity.
It
studied
widely,
both
to
gain
insight
into
brain's
intrinsic
organization
but
also
develop
markers
sensitive
changes
in
an
individual's
cognitive,
clinical,
and
developmental
state.
Despite
this,
origins
drivers
connectivity,
especially
at
level
densely
sampled
individuals,
remain
elusive.
Here,
we
leverage
novel
methodology
decompose
its
precise
framewise
contributions.
Using
two
dense
sampling
datasets,
investigate
individualized
focusing
specifically
on
role
brain
network
"events"
-
short-lived
peaked
patterns
high-amplitude
cofluctuations.
a
statistical
test
identify
events
empirical
recordings.
We
show
that
cofluctuation
expressed
during
are
repeated
across
multiple
scans
same
individual
represent
idiosyncratic
variants
template
group
level.
Lastly,
propose
simple
model
based
event
cofluctuations,
demonstrating
group-averaged
cofluctuations
suboptimal
for
explaining
participant-specific
connectivity.
Our
work
complements
recent
studies
implicating
brief
instants
primary
static,
extends
those
studies,
individualized,
positing
dynamic
basis
Network Neuroscience,
Год журнала:
2023,
Номер
7(3), С. 1181 - 1205
Опубликована: Янв. 1, 2023
Abstract
Many
studies
have
shown
that
the
human
endocrine
system
modulates
brain
function,
reporting
associations
between
fluctuations
in
hormone
concentrations
and
connectivity.
However,
how
hormonal
impact
fast
changes
network
organization
over
short
timescales
remains
unknown.
Here,
we
leverage
a
recently
proposed
framework
for
modeling
co-fluctuations
activity
of
pairs
regions
at
framewise
timescale.
In
previous
showed
time
points
corresponding
to
high-amplitude
disproportionately
contributed
time-averaged
functional
connectivity
pattern
these
co-fluctuation
patterns
could
be
clustered
into
low-dimensional
set
recurring
“states.”
assessed
relationship
states
quotidian
variation
concentrations.
Specifically,
were
interested
whether
frequency
with
which
occurred
was
related
concentration.
We
addressed
this
question
using
dense-sampling
dataset
(N
=
1
brain).
dataset,
single
individual
sampled
course
two
states:
natural
menstrual
cycle
while
subject
underwent
selective
progesterone
suppression
via
oral
contraceptives.
During
each
cycle,
30
daily
resting-state
fMRI
scans
blood
draws.
Our
analysis
imaging
data
revealed
repeating
states.
found
state
scan
sessions
significantly
correlated
follicle-stimulating
luteinizing
also
constructed
representative
networks
session
only
“event
frames”—those
when
an
event
determined
occurred.
weights
specific
subsets
connections
robustly
concentration
not
hormones,
but
estradiol.
Trends in Cognitive Sciences,
Год журнала:
2023,
Номер
27(11), С. 1068 - 1084
Опубликована: Сен. 15, 2023
Network
neuroscience
has
emphasized
the
connectional
properties
of
neural
elements
-
cells,
populations,
and
regions.
This
come
at
expense
anatomical
functional
connections
that
link
these
to
one
another.
A
new
perspective
namely
emphasizes
'edges'
may
prove
fruitful
in
addressing
outstanding
questions
network
neuroscience.
We
highlight
recently
proposed
'edge-centric'
method
review
its
current
applications,
merits,
limitations.
also
seek
establish
conceptual
mathematical
links
between
this
previously
approaches
science
neuroimaging
literature.
conclude
by
presenting
several
avenues
for
future
work
extend
refine
existing
edge-centric
analysis.
NeuroImage,
Год журнала:
2022,
Номер
260, С. 119476 - 119476
Опубликована: Июль 14, 2022
Recent
work
identified
single
time
points
("events")
of
high
regional
cofluctuation
in
functional
Magnetic
Resonance
Imaging
(fMRI)
which
contain
more
large-scale
brain
network
information
than
other,
low
points.
This
suggested
that
events
might
be
a
discrete,
temporally
sparse
signal
drives
connectivity
(FC)
over
the
timeseries.
However,
different,
not
yet
explored
possibility
is
differences
between
are
driven
by
sampling
variability
on
constant,
static,
noisy
signal.
Using
combination
real
and
simulated
data,
we
examined
relationship
structure
asked
if
this
was
unique,
or
it
could
arise
from
alone.
First,
show
discrete
-
there
gradually
increasing
cofluctuation;
∼50%
samples
very
strong
structure.
Second,
using
simulations
predicted
static
FC.
Finally,
randomly
selected
can
capture
about
as
well
events,
largely
because
their
temporal
spacing.
Together,
these
results
suggest
that,
while
exhibit
particularly
representations
FC,
little
evidence
unique
timepoints
drive
FC
Instead,
parsimonious
explanation
for
data
but
noisy,
Communications Biology,
Год журнала:
2024,
Номер
7(1)
Опубликована: Янв. 24, 2024
Abstract
Previous
studies
have
adopted
an
edge-centric
framework
to
study
fine-scale
network
dynamics
in
human
fMRI.
To
date,
however,
no
applied
this
data
collected
from
model
organisms.
Here,
we
analyze
structural
and
functional
imaging
lightly
anesthetized
mice
through
lens.
We
find
evidence
of
“bursty”
events
-
brief
periods
high-amplitude
connectivity.
Further,
show
that
on
a
per-frame
basis
best
explain
static
FC
can
be
divided
into
series
hierarchically-related
clusters.
The
co-fluctuation
patterns
associated
with
each
cluster
centroid
link
distinct
anatomical
areas
largely
adhere
the
boundaries
algorithmically
detected
brain
systems.
then
investigate
connectivity
undergirding
patterns.
induce
modular
bipartitions
inter-areal
axonal
projections.
Finally,
replicate
these
same
findings
dataset.
In
summary,
report
recapitulates
organism
many
phenomena
observed
previously
analyses
data.
However,
unlike
subjects,
murine
nervous
system
is
amenable
invasive
experimental
perturbations.
Thus,
sets
stage
for
future
investigation
causal
origins
co-fluctuations.
Moreover,
cross-species
consistency
reported
enhances
likelihood
translation.
Human Brain Mapping,
Год журнала:
2024,
Номер
45(5)
Опубликована: Март 23, 2024
Abstract
Blood‐level
oxygenation‐dependent
(BOLD)
functional
magnetic
resonance
imaging
(fMRI)
is
the
most
common
modality
to
study
connectivity
in
human
brain.
Most
research
date
has
focused
on
between
pairs
of
brain
regions.
However,
attention
recently
turned
towards
involving
more
than
two
regions,
that
is,
higher‐order
connectivity.
It
not
yet
clear
how
can
best
be
quantified.
The
measures
are
currently
use
cannot
distinguish
pairwise
(i.e.,
second‐order)
and
We
show
genuine
quantified
by
using
multivariate
cumulants.
explore
cumulants
for
quantifying
performance
block
bootstrapping
statistical
inference.
In
particular,
we
formulate
a
generative
model
fMRI
signals
exhibiting
it
assess
bias,
standard
errors,
detection
probabilities.
Application
resting‐state
data
from
Human
Connectome
Project
demonstrates
spontaneous
organized
into
networks
distinct
second‐order
networks.
clinical
cohort
patients
with
multiple
sclerosis
further
used
classify
disease
groups
explain
behavioral
variability.
Hence,
present
novel
framework
reliably
estimate
which
constructing
hyperedges,
finally,
readily
applied
populations
neuropsychiatric
or
cognitive
neuroscientific
experiments.