The
acoustic
speech
signal
cannot
be
clearly
divided
into
individual
words
and
rather
resembles
a
continuous
stream
of
sounds.
Nevertheless,
there
are
temporal
regularities
that
may
used
in
perception.
duration
language
elements
such
as
phonemes,
syllables,
phrases
is
also
reflected
the
neural
response
patterns
during
Impairments
functions
often
accompanied
by
changes
these
patterns.
Despite
findings,
it
not
clear
whether
causal
relationship
between
quality
This
article
introduces
relevant
components
signal,
describes
neuronal
to
stimuli
healthy
brain
shows
which
neurophysiological
associated
with
dysfunction.
Various
methods
non-invasive
neuromodulation
presented,
first
results
indicate
improved
through
targeted
neuromodulation.
Journal of Cognitive Enhancement,
Год журнала:
2024,
Номер
unknown
Опубликована: Авг. 6, 2024
Abstract
Transcranial
electrical
stimulation
(tES)
has
emerged
as
a
promising
tool
for
neuromodulation,
but
its
application
is
often
limited
by
the
discomfort
associated
with
higher
intensities.
Newer
variants
like
transcranial
temporal
interference
(tTIS)
utilize
high-frequency
alternating
currents
(≥
500
Hz)
to
penetrate
deeper
brain
regions
while
mitigating
perceptual
discomfort.
This
study
sought
examine
sensation
and
pain
thresholds
across
various
frequencies
of
currents,
aiming
explore
boundaries
comfortable
Additionally,
we
evaluate
efficacy
an
anesthetizing
topical
cream
in
increasing
participant
comfort
potentially
extending
range
tolerable
levels.
We
recruited
37
participants
applied
current
head
at
(10
Hz,
20
1000
2000
determine
intensity-dependent
perception
thresholds.
were
determined
under
influence
anesthetic.
Our
findings
confirm
that
frequency
increases,
perceptibility
decreases,
allowing
manyfold
increase
intensity
before
becoming
perceptible
or
causing
pain.
was
efficacious
further
reducing
sensations
all
frequencies.
lays
groundwork
future
research
establishing
limits
intensities,
particularly
context
stimulation.
The
reduced
stimulation,
coupled
effectiveness
creams,
enables
administration
intensities
more
potent
neuromodulatory
interventions
without
International Journal of Yoga,
Год журнала:
2023,
Номер
16(1), С. 42 - 48
Опубликована: Янв. 1, 2023
It
is
hypothesized
that
being
mindfully
aware
a
spontaneous
state
of
being.
imbued
with
joy,
peace
and
happiness.
Such
periodically
revealed
during
restful
attentiveness
or
presence.
also
associated
brain
alpha
activity
8-13
Hz.
In
deep
nonrapid
eye
movement
sleep,
there
synchronous
delta
at
coherent
frequency
0.1
Both
these
brainwave
ground
states
are
spontaneous,
calm
effortless.
When
any
physical
mental
effort
made,
the
rhythm
desynchronized,
it
superposed
by
faster
waves
beta
(13-30
Hz)
gamma
frequencies
(30-150
Hz).
This
stream
dualistic
conscious
experiences
contents.
During
microarousals
resulting
in
dream
experiences.
effortless,
meditative
awareness,
whole
family
synchronized
including
(a)
Occipital-parietal
visual
clarity,
formless
color,
absence
imagery
(b)
Frontal
eye-field
relatively
motionless
eyes,
voluntary
actions
plans
to
move
eyes
some
direction,
along
nonactive
working
memory,
(c)
Somatosensory
Mu
from
somatic
motor-sensory
cortex
resultant
stillness
body
head,
face,
larynx,
spine,
hands
legs,
(d)
Mid-temporal
auditory
vocal
quietness
internal
verbal
silence
(Maunam)
feeling
serenity,
(e)
Cingulate
precuneus
freedom
autobiographical
memories
sense
agency
ego.
The
insular
serves
as
gatekeeper,
hierarchical
controller
switch
between
engagement
disengagement
external
world.
switches
default
mode
network
executive
frontoparietal
networks,
sequential
parallel
modes
functioning.
Mindful
consciousness
local
dualistic,
whereas
mindful
awareness
nonlocal
nondual.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Авг. 6, 2024
Structured
Abstract
Objectives
Research
on
the
influence
of
transcranial
alternating
current
stimulation
over
alpha
functional
connectivity
(FC)
is
scarce,
and
at
same
time
poses
as
a
potential
treatment
for
various
diseases.
This
study
aimed
to
investigate
effects
individualized
frequency
tACS
(IAF-tACS)
FC
within
default
mode
network
(DMN)
in
healthy
individuals,
particularly
focusing
precuneus
(PCU)
major
hub
network.
Materials
Methods
27
participants
were
recruited,
which
underwent
20-minute
IAF-tACS
session
three
magnetoencephalography
(MEG)
recordings:
two
pre-stimulation
one
post-stimulation.
Participants
randomly
assigned
either
or
sham
group.
was
evaluated
through
corrected
imaginary
phase
locking
value
(ci-PLV)
leakage
amplitude
envelope
correlation
(AEC-c).
Statistical
analyses
compared
both
Pre-Post
ratio
between
groups
t-tests
intragroup
changes
repeated
measures
t-tests,
with
FDR
correction
applied
account
multiple
comparisons.
An
additional
analysis
simulated
cortical
folding
effect
FC.
Results
significantly
decreased
AEC-c
PCU
DMN
group
group,
especially
influencing
antero-posterior
links
hubs
DMN.
No
significant
observed
ci-PLV
metrics.
Negative
correlations
found
power
alterations
posterior
areas,
suggesting
complex
interaction
electric
field
direction.
Conclusions
Against
our
initial
hypothesis,
reduced
DMN,
possibly
due
disparities
introduced
by
gyrification.
These
findings
suggest
that
might
modulate
more
manner
than
previously
thought,
highlighting
need
further
research
into
personalized
application
neuromodulation
techniques,
well
its
therapeutic
implications
conditions
like
Alzheimer’s
disease.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Июль 25, 2023
ABSTRACT
Plantarflexors
provide
propulsion
during
walking
(late
stance)
and
receive
input
from
both
corticospinal
tract
(CST)
corticoreticulospinal
(CReST).
Both
descending
motor
tracts
exhibit
some
frequency-specificity,
which
allows
potential
differentiation
of
neural
drive
each
using
intermuscular
coherence
(IMC).
Stroke
may
differentially
affect
tract,
thus
impair
the
function
plantarflexors.
However,
evidence
concerning
this
frequency-specificity
its
relation
to
plantarflexors’
neuromechanics
post-stroke
remains
very
limited.
Here,
we
investigated
coherences
alpha,
beta,
low-gamma
bands
between
Soleus
(SOL),
Lateral
Gastrocnemius
(LG),
Medial
(MG)
muscles
their
relationships
with
walking-specific
measures
(propulsive
impulse;
speed).
Fourteen
individuals
chronic
stroke
walked
on
a
treadmill
at
self-selected
fast
speed
(SSWS
FWS,
respectively).
Inter-limb
IMC
comparisons
revealed
that
beta
LG-MG
(SSWS)
SOL-LG
(FWS)
IMCs
were
degraded
paretic
side.
At
same
time,
within
limb,
IMCs,
significantly
different
surrogate
dataset
denoting
random
coherence,
in
alpha
band
(both
speeds).
Further,
was
positively
correlated
propulsive
impulse
limb
(SSWS).
Findings
suggest
differential
functional
role
beta/low-gamma,
be
related
underlying
drives.
The
persistence
plantarflexors
strong
positive
relationship
suggests
relative
preservation
and/or
upregulation
CReST.
Future
research
should
address
whether
entraining
system
frequencies
via
neuromodulation
can
improve
neuromechanical
subsequently
promote
recovery.
Key
Points
Summary
Cortical
subcortical
drives
frequency-specific,
have
walking,
after
stroke.
Whether
exists
how
it
is
ankle
determined.
bilaterally
for
speed)
post-stroke.
(self-selected
(fast
Alpha
present
across
mainly
non-paretic
side
Paretic
Given
impaired
post-stroke,
frequency
Background:
Transcranial
Alternating
Current
Stimulation
(tACS)
employs
low-intensity
sinusoidal
currents
to
influence
cortical
plasticity
and
motor
function.
Despite
extensive
research,
inconsistent
results
require
a
comprehensive
review
of
tACS
efficacy.
Objective:
This
study
systematically
assesses
effects
on
corticospinal
intracortical
excitability,
function
over
the
cortex
(M1),
focusing
alpha,
beta,
gamma
frequencies.
Methods:
Relevant
studies
were
identified
through
database
searches
citations
tracked
until
July
10,
2023.
The
methodological
quality
included
(29)
was
evaluated
by
Downs
Black.
Data
synthesis
involved
meta-analysis
(n=25)
best
evidence
(n=5).
Results:
Meta-analysis
showed
that
alpha
beta
(>1
mA)
increased
excitability
(CSE).
Alpha,
improved
Sub-analysis
both
≤1
mA
function,
whilst
at
2
Notably,
online
offline
regardless
stimulation
factors.
Conclusion:
modulates
CSE
improves
with
outcomes
dependent
parameters
timing.
The
acoustic
speech
signal
cannot
be
clearly
divided
into
individual
words
and
rather
resembles
a
continuous
stream
of
sounds.
Nevertheless,
there
are
temporal
regularities
that
may
used
in
perception.
duration
language
elements
such
as
phonemes,
syllables,
phrases
is
also
reflected
the
neural
response
patterns
during
Impairments
functions
often
accompanied
by
changes
these
patterns.
Despite
findings,
it
not
clear
whether
causal
relationship
between
quality
This
article
introduces
relevant
components
signal,
describes
neuronal
to
stimuli
healthy
brain
shows
which
neurophysiological
associated
with
dysfunction.
Various
methods
non-invasive
neuromodulation
presented,
first
results
indicate
improved
through
targeted
neuromodulation.
