bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2023,
Volume and Issue:
unknown
Published: July 19, 2023
There
is
rich
variety
in
the
activity
of
single
neurons
recorded
during
behaviour.
Yet,
these
diverse
neuron
responses
can
be
well
described
by
relatively
few
patterns
neural
co-modulation.
The
study
such
low-dimensional
structure
population
has
provided
important
insights
into
how
brain
generates
Virtually
all
studies
have
used
linear
dimensionality
reduction
techniques
to
estimate
population-wide
co-modulation
patterns,
constraining
them
a
flat
“neural
manifold”.
Here,
we
hypothesised
that
since
nonlinear
and
make
thousands
distributed
recurrent
connections
likely
amplify
nonlinearities,
manifolds
should
intrinsically
nonlinear.
Combining
recordings
from
monkey,
mouse,
human
motor
cortex,
mouse
striatum,
show
that:
1)
are
nonlinear;
2)
their
nonlinearity
becomes
more
evident
complex
tasks
require
varied
patterns;
3)
manifold
varies
across
architecturally
distinct
regions.
Simulations
using
network
models
confirmed
proposed
relationship
between
circuit
connectivity
nonlinearity,
including
differences
Thus,
underlying
generation
behaviour
inherently
nonlinear,
properly
accounting
for
nonlinearities
will
critical
as
neuroscientists
move
towards
studying
numerous
regions
involved
increasingly
naturalistic
behaviours.
Current Opinion in Neurobiology,
Journal Year:
2021,
Volume and Issue:
70, P. 137 - 144
Published: Oct. 1, 2021
Advances
in
experimental
neuroscience
have
transformed
our
ability
to
explore
the
structure
and
function
of
neural
circuits.
At
same
time,
advances
machine
learning
unleashed
remarkable
computational
power
artificial
networks
(ANNs).
While
these
two
fields
different
tools
applications,
they
present
a
similar
challenge:
namely,
understanding
how
information
is
embedded
processed
through
high-dimensional
representations
solve
complex
tasks.
One
approach
addressing
this
challenge
utilize
mathematical
analyze
geometry
representations,
i.e.,
population
geometry.
We
review
examples
geometrical
approaches
providing
insight
into
biological
networks:
representation
untangling
perception,
geometric
theory
classification
capacity,
disentanglement
abstraction
cognitive
systems,
topological
underlying
maps,
dynamic
motor
dynamical
cognition.
Together,
findings
illustrate
an
exciting
trend
at
intersection
learning,
neuroscience,
geometry,
which
provides
useful
population-level
mechanistic
descriptor
task
implementation.
Importantly,
descriptions
are
applicable
across
sensory
modalities,
brain
regions,
network
architectures
timescales.
Thus,
has
potential
unify
networks,
bridging
gap
between
single
neurons,
populations
behavior.
Science,
Journal Year:
2022,
Volume and Issue:
375(6581), P. 632 - 639
Published: Feb. 10, 2022
How
the
brain
stores
a
sequence
in
memory
remains
largely
unknown.
We
investigated
neural
code
underlying
working
using
two-photon
calcium
imaging
to
record
thousands
of
neurons
prefrontal
cortex
macaque
monkeys
memorizing
and
then
reproducing
locations
after
delay.
discovered
regular
geometrical
organization:
The
high-dimensional
state
space
during
delay
could
be
decomposed
into
sum
low-dimensional
subspaces,
each
storing
spatial
location
at
given
ordinal
rank,
which
generalized
novel
sequences
explain
monkey
behavior.
rank
subspaces
were
distributed
across
large
overlapping
groups,
integration
information
occurred
collective
level
rather
than
within
single
neurons.
Thus,
simple
representational
geometry
underlies
memory.
Trends in Cognitive Sciences,
Journal Year:
2024,
Volume and Issue:
28(7), P. 662 - 676
Published: April 23, 2024
Beta
oscillations
are
linked
to
the
control
of
goal-directed
processing
sensory
information
and
timing
motor
output.
Recent
evidence
demonstrates
they
not
sustained
but
organized
into
intermittent
high-power
bursts
mediating
timely
functional
inhibition.
This
implies
there
is
a
considerable
moment-to-moment
variation
in
neural
dynamics
supporting
cognition.
thus
offer
new
opportunities
for
studying
how
inputs
selectively
processed,
reshaped
by
inhibitory
cognitive
operations
ultimately
result
actions.
method
advances
reveal
diversity
beta
that
provide
deeper
insights
their
function
underlying
circuit
activity
motifs.
We
propose
brain-wide,
spatiotemporal
patterns
bursting
reflect
various
nonlinear
aspects
cortical
processing.
