bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Июнь 13, 2024
A
crucial
challenge
in
neuroscience
involves
characterising
brain
dynamics
from
high-dimensional
recordings.
Dynamic
Functional
Connectivity
(dFC)
is
an
analysis
paradigm
that
aims
to
address
this
challenge.
dFC
consists
of
a
time-varying
matrix
(dFC
matrix)
expressing
how
pairwise
interactions
across
areas
change
with
time.
However,
the
main
approaches
have
been
developed
and
applied
mostly
empirically,
lacking
unifying
theoretical
framework,
general
interpretation,
common
set
measures
quantify
matrices
properties.
Moreover,
field
has
ad-hoc
algorithms
compute
process
efficiently.
This
prevented
show
its
full
potential
datasets
and/or
real
time
applications.
With
paper,
we
introduce
Symmetric
Matrix
framework
(DySCo),
associated
repository.
DySCo
approach
allows
study
signals
at
different
spatio-temporal
scales,
down
voxel
level,
computationally
ultrafast.
unifies
single
most
employed
matrices,
which
share
mathematical
structure.
Doing
so
it
allows:
1)
new
interpretation
further
justifies
use
capture
spatiotemporal
patterns
data
form
easily
translatable
imaging
modalities.
2)
The
introduction
Recurrence
EVD
store
eigenvectors
eigenvalues
all
types
efficent
manner
orders
magnitude
faster
than
naive
algorithms,
without
loss
information.
3)
To
simply
define
quantities
interest
for
dynamic
analyses
such
as:
amount
connectivity
(norm
similarity
between
their
informational
complexity.
methodology
here
validated
on
both
synthetic
dataset
rest/N-back
task
experimental
-
fMRI
Human
Connectome
Project
dataset.
We
demonstrate
proposed
are
highly
sensitive
changes
configurations.
illustrate
computational
efficiency
toolbox,
perform
voxel-level,
very
demanding
afforded
by
RMEVD
algorithm.
Proceedings of the National Academy of Sciences,
Год журнала:
2025,
Номер
122(5)
Опубликована: Янв. 27, 2025
The
preference
for
simple
explanations,
known
as
the
parsimony
principle,
has
long
guided
development
of
scientific
theories,
hypotheses,
and
models.
Yet
recent
years
have
seen
a
number
successes
in
employing
highly
complex
models
inquiry
(e.g.,
3D
protein
folding
or
climate
forecasting).
In
this
paper,
we
reexamine
principle
light
these
technological
advancements.
We
review
developments,
including
surprising
benefits
modeling
with
more
parameters
than
data,
increasing
appreciation
context-sensitivity
data
misspecification
models,
new
tools.
By
integrating
insights,
reassess
utility
proxy
desirable
model
traits,
such
predictive
accuracy,
interpretability,
effectiveness
guiding
research,
resource
efficiency.
conclude
that
are
sometimes
essential
progress,
discuss
ways
which
complexity
can
play
complementary
roles
practice.
PLoS Computational Biology,
Год журнала:
2025,
Номер
21(3), С. e1012795 - e1012795
Опубликована: Март 7, 2025
A
crucial
challenge
in
neuroscience
involves
characterising
brain
dynamics
from
high-dimensional
recordings.
Dynamic
Functional
Connectivity
(dFC)
is
an
analysis
paradigm
that
aims
to
address
this
challenge.
dFC
consists
of
a
time-varying
matrix
(dFC
matrix)
expressing
how
pairwise
interactions
across
areas
change
over
time.
However,
the
main
approaches
have
been
developed
and
applied
mostly
empirically,
lacking
common
theoretical
framework
clear
view
on
interpretation
results
derived
matrices.
Moreover,
community
has
not
using
most
efficient
algorithms
compute
process
matrices
efficiently,
which
prevented
showing
its
full
potential
with
datasets
and/or
real-time
applications.
In
paper,
we
introduce
Symmetric
Matrix
(DySCo),
associated
repository.
DySCo
presents
commonly
used
measures
language
implements
them
computationally
way.
This
allows
study
activity
at
different
spatio-temporal
scales,
down
voxel
level.
provides
single
to:
(1)
Use
as
tool
capture
interaction
patterns
data
form
easily
translatable
imaging
modalities.
(2)
Provide
comprehensive
set
quantify
properties
evolution
time:
amount
connectivity,
similarity
between
matrices,
their
informational
complexity.
By
combining
it
possible
perform
analysis.
(3)
Leverage
Temporal
Covariance
EVD
algorithm
(TCEVD)
store
eigenvectors
values
then
also
EVD.
Developing
eigenvector
space
orders
magnitude
faster
more
memory
than
naïve
space,
without
loss
information.
The
methodology
here
validated
both
synthetic
dataset
rest/N-back
task
experimental
fMRI
Human
Connectome
Project
dataset.
We
show
all
proposed
are
sensitive
changes
configurations
consistent
time
subjects.
To
illustrate
computational
efficiency
toolbox,
performed
level,
demanding
but
afforded
by
TCEVD.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Март 20, 2024
Task
errors
are
used
to
learn
and
refine
motor
skills.
We
investigated
how
task
assistance
influences
learned
neural
representations
using
Brain-Computer
Interfaces
(BCIs),
which
map
activity
into
movement
via
a
decoder.
analyzed
cortex
as
monkeys
practiced
BCI
with
decoder
that
adapted
improve
or
maintain
performance
over
days.
The
dimensionality
of
the
population
neurons
controlling
remained
constant
increased
learning,
counter
expected
trends
from
learning.
Yet,
time,
information
was
contained
in
smaller
subset
modes.
Moreover,
ultimately
stored
modes
occupied
small
fraction
variance.
An
artificial
network
model
suggests
adaptive
decoders
contribute
forming
these
compact
representations.
Our
findings
show
assistive
manipulate
error
for
long-term
learning
computations,
like
credit
assignment,
informs
our
understanding
has
implications
designing
real-world
BCIs.
The
preference
for
simpler
explanations,
known
as
the
parsimony
principle,
has
long
guided
development
of
scientific
theories,
hypotheses,
and
models.
Yet
recent
years
have
seen
a
number
successes
in
employing
highly
complex
models
inquiry
(e.g.,
3D
protein
folding
or
climate
forecasting).
In
this
paper,
we
re-examine
principle
light
these
technological
advancements.
We
review
developments,
including
surprising
benefits
modeling
with
more
parameters
than
data,
increasing
appreciation
context-sensitivity
data
misspecification
models,
new
tools.
By
integrating
insights,
reassess
utility
proxy
desirable
model
traits,
such
predictive
accuracy,
interpretability,
effectiveness
guiding
research,
resource
efficiency.
conclude
that
are
sometimes
essential
progress,
discuss
ways
which
complexity
can
play
complementary
roles
practice.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Ноя. 8, 2023
Neural
activity
in
awake
organisms
shows
widespread
and
spatiotemporally
diverse
correlations
with
behavioral
physiological
measurements.
We
propose
that
this
covariation
reflects
part
the
dynamics
of
a
unified,
multidimensional
arousal-related
process
regulates
brain-wide
physiology
on
timescale
seconds.
By
framing
interpretation
within
dynamical
systems
theory,
we
arrive
at
surprising
prediction:
single,
scalar
measurement
arousal
(e.g.,
pupil
diameter)
should
suffice
to
reconstruct
continuous
evolution
multidimensional,
spatiotemporal
measurements
large-scale
brain
physiology.
To
test
hypothesis,
perform
multimodal,
cortex-wide
optical
imaging
monitoring
mice.
demonstrate
neuronal
calcium,
metabolism,
blood-oxygen
can
be
accurately
parsimoniously
modeled
from
low-dimensional
state-space
reconstructed
time
history
diameter.
Extending
framework
electrophysiological
Allen
Brain
Observatory,
ability
integrate
experimental
data
into
unified
generative
model
via
mappings
an
intrinsic
manifold.
Our
results
support
hypothesis
spontaneous,
spatially
structured
fluctuations
physiology-widely
interpreted
reflect
regionally-specific
neural
communication-are
large
reflections
process.
This
enriched
view
has
broad
implications
for
interpreting
observations
brain,
body,
behavior
as
measured
across
modalities,
contexts,
scales.