Journal of Neuroscience,
Год журнала:
2023,
Номер
43(23), С. 4352 - 4364
Опубликована: Май 9, 2023
Cognitive
demand
is
thought
to
modulate
two
often
used,
but
rarely
combined,
measures:
pupil
size
and
neural
α
(8-12
Hz)
oscillatory
power.
However,
it
unclear
whether
these
measures
capture
cognitive
in
a
similar
way
under
complex
audiovisual-task
conditions.
Here
we
recorded
power
(using
electroencephalography),
while
human
participants
of
both
sexes
concurrently
performed
visual
multiple
object-tracking
task
an
auditory
gap
detection
task.
Difficulties
the
tasks
were
manipulated
independent
each
other.
Participants'
performance
decreased
accuracy
speed
with
increasing
demand.
Pupil
increased
difficulty
for
In
contrast,
showed
diverging
dynamics:
parietal
task,
not
Furthermore,
difficulty,
within-participant
trial-by-trial
fluctuations
negatively
correlated
Difficulty-induced
changes
power,
however,
did
correlate,
which
consistent
their
different
cognitive-demand
sensitivities.
Overall,
current
study
demonstrates
that
dynamics
neurophysiological
indices
associated
effort
are
multifaceted
potentially
modality-dependent
Fluctuations
in
brain
and
behavioral
state
are
supported
by
broadly
projecting
neuromodulatory
systems.
In
this
study,
we
use
mesoscale
two-photon
calcium
imaging
to
examine
spontaneous
activity
of
cholinergic
noradrenergic
axons
awake
mice
order
determine
the
interaction
between
arousal/movement
transitions
across
dorsal
cortex
at
distances
separated
up
4
mm.
We
confirm
that
GCaMP6s
within
axonal
projections
both
basal
forebrain
locus
coeruleus
neurons
track
arousal,
indexed
as
pupil
diameter,
changes
engagement,
reflected
bouts
whisker
movement
and/or
locomotion.
The
broad
coordination
even
distant
segments
indicates
these
systems
can
communicate,
part,
through
a
global
signal,
especially
relation
state.
addition
coordinated
activity,
also
find
evidence
subpopulation
may
exhibit
heterogeneity
appears
be
independent
our
measures
By
monitoring
interneurons
cortex,
found
cells
state-dependent
(arousal/movement)
activity.
These
results
demonstrate
provide
prominent
synchronized
signal
related
state,
therefore
contribute
cortical
excitability.
Brain stimulation,
Год журнала:
2024,
Номер
17(2), С. 233 - 244
Опубликована: Фев. 28, 2024
BackgroundTranscutaneous
auricular
vagus
nerve
stimulation
(tVNS
or
taVNS)
is
a
non-invasive
method
of
electrical
the
afferent
pathway
nerve,
suggested
to
drive
changes
in
putative
physiological
markers
noradrenergic
activity,
including
pupil
dilation.ObjectiveHowever,
it
unknown
whether
different
taVNS
modes
can
map
onto
phasic
and
tonic
activity.
The
effects
on
dilation
humans
are
inconsistent,
largely
due
differences
protocols.
Here,
we
attempted
address
these
issues.MethodsWe
investigated
under
(1
s)
(30
taVNS,
pre-registered,
single-blind,
sham-controlled,
within-subject
cross-over
design,
absence
behavioural
task.ResultsPhasic
induced
rapid
increase
size
over
baseline,
significantly
greater
than
sham
stimulation,
which
rapidly
declined
after
offset.
Tonic
similarly
(and
larger
sham)
returning
baseline
within
5
s,
despite
ongoing
stimulation.
Thus,
both
active
closely
resembled
effect.
There
were
no
size,
sustained
size.ConclusionsThese
results
suggest
that
phasic-
tonic-like
standard
parameters
may
modulate
primarily
mode
as
indexed
by
evoked
dilation,
above
somatosensory
effects.
This
result
sheds
light
temporal
profile
with
implications
for
their
applicability
further
research.
Neuron,
Год журнала:
2024,
Номер
112(20), С. 3381 - 3395
Опубликована: Июнь 25, 2024
Pupil
size
is
a
widely
used
metric
of
brain
state.
It
one
the
few
signals
originating
from
that
can
be
readily
monitored
with
low-cost
devices
in
basic
science,
clinical,
and
home
settings.
is,
therefore,
important
to
investigate
generate
well-defined
theories
related
specific
interpretations
this
metric.
What
exactly
does
it
tell
us
about
brain?
Pupils
constrict
response
light
dilate
during
darkness,
but
also
controls
pupil
irrespective
luminosity.
fluctuations
resulting
ongoing
"brain
states"
are
as
arousal,
what
pupil-linked
arousal
how
should
interpreted
neural,
cognitive,
computational
terms?
Here,
we
discuss
some
recent
findings
these
issues.
We
identify
open
questions
propose
answer
them
through
combination
tasks,
neurocomputational
models,
neurophysiological
probing
interconnected
loops
causes
consequences
size.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Фев. 28, 2025
Abstract
Recent
animal
research
has
revealed
the
intricate
dynamics
of
arousal
levels
that
are
important
for
maintaining
proper
sleep
resilience
and
memory
consolidation.
In
humans,
changes
in
level
believed
to
be
a
determining
characteristic
healthy
pathological
but
tracking
fluctuations
been
methodologically
challenging.
Here
we
measured
pupil
size,
an
established
indicator
levels,
by
safely
taping
right
eye
open
during
overnight
tested
whether
size
affects
cortical
response
auditory
stimulation.
We
show
change
as
function
events
across
different
temporal
scales.
particular,
our
results
inversely
related
occurrence
spindle
clusters,
marker
resilience.
Additionally,
found
prior
stimulation
influence
evoked
response,
most
notably
delta
power,
several
restorative
regenerative
functions
sleep.
Recording
provides
insights
into
interplay
between
oscillations.
A
variety
of
psychological
and
physical
phenomena
elicit
variations
in
the
diameter
pupil
eye.
Changes
size
are
mediated
by
relative
activation
sphincter
pupillae
muscle
(decrease
diameter)
dilator
(increase
diameter),
innervated
parasympathetic
sympathetic
branches,
respectively,
autonomic
nervous
system.
The
current
guidelines
intended
to
inform
guide
psychophysiological
research
involving
measurement
(1)
summarizing
important
aspects
concerning
physiology
pupil,
(2)
providing
methodological
data-analytic
recommendations,
(3)
briefly
reviewing
that
modulate
pupillary
reactivity.
Because
increased
ease
tractability
measurement,
goal
these
is
promote
accurate
recording,
analysis,
reporting
data
research.
The
pupil
dilates
and
reconstricts
following
task
events.
It
is
popular
to
model
this
task-evoked
response
as
a
linear
transformation
of
event-locked
impulses,
whose
amplitudes
are
used
estimates
arousal.
We
show
that
incorrect
propose
an
alternative
based
on
the
physiological
finding
common
neural
input
drives
saccades
size.
arousal
from
our
agreed
with
key
predictions:
Arousal
scaled
difficulty
behavioral
performance
but
was
invariant
small
differences
in
trial
duration.
Moreover,
offers
unified
explanation
for
wide
range
phenomena:
entrainment
size
timing,
modulation
amplitude
noise
difficulty,
reaction
time-dependent
timing
amplitude,
constrictory
time-locked
saccades,
task-dependent
distortion
saccade-locked
response.
Journal of sport and health science/Journal of Sport and Health Science,
Год журнала:
2023,
Номер
12(5), С. 568 - 591
Опубликована: Май 5, 2023
There
is
a
growing
interest
to
understand
the
neurobiological
mechanisms
that
drive
positive
associations
of
physical
activity
and
fitness
with
measures
cognitive
performance.
To
better
those
mechanisms,
several
studies
have
employed
eye-based
(e.g.,
eye
movement
such
as
saccades,
pupillary
pupil
dilation,
vascular
retinal
vessel
diameter)
deemed
be
proxies
for
specific
mechanisms.
However,
there
currently
no
systematic
review
providing
comprehensive
overview
these
in
field
exercise-cognition
science.
Thus,
this
aimed
address
gap
literature.
identify
eligible
studies,
we
searched
5
electronic
databases
on
October
23,
2022.
Two
researchers
independently
extracted
data
assessed
risk
bias
using
modified
version
Tool
assEssment
Study
qualiTy
reporting
EXercise
(TESTEX
scale,
interventional
studies)
critical
appraisal
tool
from
Joanna
Briggs
Institute
(for
cross-sectional
studies).
Our
(n
=
35
offers
following
main
findings:
(a)
insufficient
evidence
available
draw
solid
conclusions
concerning
gaze-fixation-based
measures;
(b)
pupillometric
measures,
which
are
proxy
noradrenergic
system,
can
explain
effect
acute
exercise
cardiorespiratory
performance
mixed;
(c)
training-
or
fitness-related
changes
cerebrovascular
system
(operationalized
via
vasculature)
are,
general,
positively
associated
improvements;
(d)
chronic
exercises
show
based
an
oculomotor-based
measure
executive
function
antisaccade
tasks);
(e)
association
between
partly
mediated
by
dopaminergic
spontaneous
eye-blink
rate).
This
confirmation
provide
valuable
insight
into
may
due
limited
number
utilizing
methods
obtaining
pupillometry,
analysis,
blink
rate)
investigating
possible
dose–response
relationship,
further
research
necessary
before
more
nuanced
drawn.
Given
economical
non-invasive,
hope
will
foster
future
application
Neuromodulatory
nuclei
that
are
part
of
the
ascending
arousal
system
(AAS)
play
a
crucial
role
in
regulating
cortical
state
and
optimizing
task
performance.
Pupil
diameter,
under
constant
luminance
conditions,
is
increasingly
used
as
an
index
activity
these
AAS
nuclei.
Indeed,
task-based
functional
imaging
studies
humans
have
begun
to
provide
evidence
stimulus-driven
pupil-AAS
coupling.
However,
whether
there
such
tight
coupling
during
rest
not
clear.
To
address
this
question,
we
examined
simultaneously
acquired
resting-state
fMRI
pupil-size
data
from
74
participants,
focusing
on
six
nuclei:
locus
coeruleus,
ventral
tegmental
area,
substantia
nigra,
dorsal
median
raphe
nuclei,
cholinergic
basal
forebrain.
Activation
all
was
optimally
correlated
with
pupil
size
at
0-2
s
lags,
suggesting
spontaneous
changes
were
almost
immediately
followed
by
corresponding
BOLD-signal
AAS.
These
results
suggest
occur
states
can
be
noninvasive
general
Importantly,
nature
appears
vastly
different
relatively
slow
canonical
hemodynamic
response
function
has
been
characterize
task-related
Alzheimer s Research & Therapy,
Год журнала:
2025,
Номер
17(1)
Опубликована: Фев. 27, 2025
Abstract
Background
Alzheimer’s
disease
(AD)
is
the
leading
cause
of
dementia,
and
early
detection
disease-associated
changes
allows
interventions.
The
locus
coeruleus
(LC)
has
been
reported
to
be
first
brain
region
develop
tau
pathology
in
AD.
However,
functional
network
LC
both
healthy
aging
AD
largely
unknown
due
technical
difficulties
associated
with
small
size
LC.
In
this
study,
we
used
measurement
spontaneous
pupil
constriction/dilation
as
a
surrogate
for
activity
study
during
aging.
Methods
Thirty-seven
younger
thirty-nine
older
adults
were
included
from
Emory
Healthy
Brain
Study
underwent
resting-state
MRI
while
simultaneously
tracking
diameter.
measurements
diameter
dynamics
reference
signals
connectivity
analysis.
identified
networks
was
then
compared
between
participants.
Correlations
regions
neuropsychological
assessments
cerebrospinal
fluid
(CSF)
biomarkers
also
evaluated.
Results
A
20
clusters
identified,
including
well
functionally
connected
found
positively
correlate
salience
negatively
central
executive
network.
Functional
decreased
within
memory,
executive,
visuospatial
functioning.
CSF
total
closely
correlated
Conclusions
Pupil
provide
valuable
insights
into
LC-related
processes.
While
they
are
not
solely
influenced
by
activity,
constrictor/dilatory
shows
promise
non-invasive
approach
probe
warrants
further
studies
evaluate
its
value
an
biomarker