Imaging Neuroscience,
Journal Year:
2024,
Volume and Issue:
2, P. 1 - 22
Published: Jan. 1, 2024
Abstract
Dynamic
Causal
Models
(DCMs)
in
functional
Magnetic
Resonance
Imaging
(fMRI)
decipher
causal
interactions,
known
as
Effective
Connectivity,
among
neuronal
populations.
However,
their
utility
is
often
constrained
by
computational
limitations,
restricting
analysis
to
a
small
subset
of
interacting
brain
areas,
typically
fewer
than
10,
thus
lacking
scalability.
While
the
regression
DCM
(rDCM)
has
emerged
faster
alternative
traditional
DCMs,
it
not
without
its
including
linearization
terms,
reliance
on
fixed
Hemodynamic
Response
Function
(HRF),
and
an
inability
accommodate
modulatory
influences.
In
response
these
challenges,
we
propose
novel
hybrid
approach
named
Transformer
encoder
decoder
(TREND),
which
combines
with
state-of-the-art
physiological
(P-DCM)
decoder.
This
innovative
method
addresses
scalability
issue
while
preserving
nonlinearities
inherent
equations.
Through
extensive
simulations,
validate
TREND’s
efficacy
demonstrating
ability
accurately
predict
effective
connectivity
values
dramatically
reduced
time
relative
original
P-DCM
even
networks
comprising
up
to,
for
instance,
100
regions.
Furthermore,
showcase
TREND
empirical
fMRI
dataset
superior
accuracy
and/or
speed
compared
other
variants.
summary,
amalgamating
Transformer,
introduce
pioneering
determining
regions,
extending
applicability
seamlessly
large-scale
networks.
Journal of Neural Engineering,
Journal Year:
2023,
Volume and Issue:
20(4), P. 046007 - 046007
Published: June 20, 2023
Abstract
Objectives
.
Recent
event-based
analyses
of
transient
neural
activities
have
characterized
the
oscillatory
bursts
as
a
signature
that
bridges
dynamic
states
to
cognition
and
behaviors.
Following
this
insight,
our
study
aimed
(1)
compare
efficacy
common
burst
detection
algorithms
under
varying
signal-to-noise
ratios
event
durations
using
synthetic
signals
(2)
establish
strategic
guideline
for
selecting
optimal
algorithm
real
datasets
with
undefined
properties.
Approach.
We
tested
robustness
simulation
dataset
comprising
multiple
frequencies.
To
systematically
assess
their
performance,
we
used
metric
called
‘detection
confidence’,
quantifying
classification
accuracy
temporal
precision
in
balanced
manner.
Given
properties
empirical
data
are
often
unknown
advance,
then
proposed
selection
rule
identify
an
given
validated
its
application
on
local
field
potentials
basolateral
amygdala
recorded
from
male
mice
(n=8)
exposed
natural
threat.
Main
Results.
Our
simulation-based
evaluation
demonstrated
is
contingent
upon
duration,
whereas
accurately
pinpointing
onsets
more
susceptible
noise
level.
For
data,
chosen
based
exhibited
superior
accuracy,
although
statistical
significance
differed
across
frequency
bands.
Notably,
by
human
visual
screening
one
recommended
rule,
implying
potential
misalignment
between
priors
mathematical
assumptions
algorithms.
Significance.
Therefore,
findings
underscore
precise
fundamentally
influenced
algorithm.
The
algorithm-selection
suggests
potentially
viable
solution,
while
also
emphasizing
inherent
limitations
originating
algorithmic
design
volatile
performances
datasets.
Consequently,
cautions
against
relying
solely
heuristic-based
approaches,
advocating
careful
studies.
Brain Communications,
Journal Year:
2023,
Volume and Issue:
6(1)
Published: Dec. 28, 2023
Motor
recovery
is
still
limited
for
people
with
stroke
especially
those
greater
functional
impairments.
In
order
to
improve
outcome,
we
need
understand
more
about
the
mechanisms
underpinning
recovery.
Task-unbiased,
blood
flow-independent
post-stroke
neural
activity
can
be
acquired
from
resting
brain
electrophysiological
recordings
and
offers
substantial
promise
investigate
physiological
mechanisms,
but
behaviourally
relevant
features
of
resting-state
sensorimotor
network
dynamics
have
not
yet
been
identified.
Thirty-seven
subcortical
ischaemic
unilateral
hand
paresis
any
degree
were
longitudinally
evaluated
at
3
weeks
(early
subacute)
12
(late
after
stroke.
Resting-state
magnetoencephalography
clinical
scores
motor
function
recorded
compared
matched
controls.
Magnetoencephalography
data
decomposed
using
a
data-driven
hidden
Markov
model
into
10
time-varying
networks.
People
showed
statistically
significantly
improved
Action
Research
Arm
Test
Fugl-Meyer
upper
extremity
between
(both
Neural
activity
contains
rich
spatiotemporal
structure
that
corresponds
to
cognition.
This
includes
oscillatory
bursting
and
dynamic
span
across
networks
of
brain
regions,
all
which
can
occur
on
timescales
tens
milliseconds.
While
these
processes
be
accessed
through
recordings
imaging,
modeling
them
presents
methodological
challenges
due
their
fast
transient
nature.
Furthermore,
the
exact
timing
duration
interesting
cognitive
events
are
often
a
priori
unknown.
Here,
we
present
OHBA
Software
Library
Dynamics
Toolbox
(osl-dynamics),
Python-based
package
identify
describe
recurrent
dynamics
in
functional
neuroimaging
data
as
At
its
core
machine
learning
generative
models
able
adapt
learn
timing,
well
spatial
spectral
characteristics,
with
few
assumptions.
osl-dynamics
incorporates
state-of-the-art
approaches
be,
have
been,
used
elucidate
wide
range
types,
including
magneto/electroencephalography,
magnetic
resonance
invasive
local
field
potential
recordings,
electrocorticography.
It
also
provides
novel
summary
measures
inform
our
understanding
cognition,
behavior,
disease.
We
hope
will
further
function,
ability
enhance
processes.
Predicting
an
individual's
cognitive
traits
or
clinical
condition
using
brain
signals
is
a
central
goal
in
modern
neuroscience.
This
commonly
done
either
structural
aspects,
such
as
connectivity
cortical
thickness,
aggregated
measures
of
activity
that
average
over
time.
But
these
approaches
are
missing
aspect
function:
the
unique
ways
which
unfolds
One
reason
why
dynamic
patterns
not
usually
considered
they
have
to
be
described
by
complex,
high-dimensional
models;
and
it
unclear
how
best
use
models
for
prediction.
We
here
propose
approach
describes
functional
amplitude
Hidden
Markov
model
(HMM)
combines
with
Fisher
kernel,
can
used
predict
individual
traits.
The
kernel
constructed
from
HMM
mathematically
principled
manner,
thereby
preserving
structure
underlying
model.
show
here,
fMRI
data,
HMM-Fisher
accurate
reliable.
compare
other
prediction
methods,
both
time-varying
time-averaged
connectivity-based
models.
Our
leverages
information
about
has
broad
applications
neuroscience
personalised
medicine.
Imaging Neuroscience,
Journal Year:
2024,
Volume and Issue:
2, P. 1 - 22
Published: Jan. 1, 2024
Abstract
Dynamic
Causal
Models
(DCMs)
in
functional
Magnetic
Resonance
Imaging
(fMRI)
decipher
causal
interactions,
known
as
Effective
Connectivity,
among
neuronal
populations.
However,
their
utility
is
often
constrained
by
computational
limitations,
restricting
analysis
to
a
small
subset
of
interacting
brain
areas,
typically
fewer
than
10,
thus
lacking
scalability.
While
the
regression
DCM
(rDCM)
has
emerged
faster
alternative
traditional
DCMs,
it
not
without
its
including
linearization
terms,
reliance
on
fixed
Hemodynamic
Response
Function
(HRF),
and
an
inability
accommodate
modulatory
influences.
In
response
these
challenges,
we
propose
novel
hybrid
approach
named
Transformer
encoder
decoder
(TREND),
which
combines
with
state-of-the-art
physiological
(P-DCM)
decoder.
This
innovative
method
addresses
scalability
issue
while
preserving
nonlinearities
inherent
equations.
Through
extensive
simulations,
validate
TREND’s
efficacy
demonstrating
ability
accurately
predict
effective
connectivity
values
dramatically
reduced
time
relative
original
P-DCM
even
networks
comprising
up
to,
for
instance,
100
regions.
Furthermore,
showcase
TREND
empirical
fMRI
dataset
superior
accuracy
and/or
speed
compared
other
variants.
summary,
amalgamating
Transformer,
introduce
pioneering
determining
regions,
extending
applicability
seamlessly
large-scale
networks.