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From YouTube: Numenta Research Meeting - Feb 5, 2020
Description
Some discussion of Local Field Potential (LFP) from Florian, probably some random discussion of other things.
https://discourse.numenta.org/t/numenta-research-meeting-feb-5-2020/7147
A
A
A
Anyway,
so
the
point
was
just
to
quickly
break
down
an
understanding
of
that,
and
could
we
switch
to
the
other
paper
which
is
going
to
be
the
most
important
one?
So
I
went
through
this
review
by
which
is
probably
the
most
authoritative
review
on
a
piece
given
that's
been
cited
over
2,000
times
in
2300
citations
or
something
like
that.
It's
not.
B
A
A
A
B
A
B
B
A
D
D
A
E
F
F
A
A
The
forward
properties
of
the
local
field
potential
are
ever
perfectly
understood
or
very
near
perfectly
understood,
is
not
really
much
of
a
mystery.
So
we
can
trust
these
simulation
models
and
what
you
see
there
with
the
lines
is,
essentially
you
see
the
drop-off
and
the
extracellular
fluid
near
the
excitation
at
that
blue
dot
there,
where
we
emulate
in
the
air
and
the
epical
temperate.
F
A
D
A
Of
sodium
ions
right,
you
have
of
course,
a
return
current
over
the
entire
norm,
because
it's
internally
connected
so
the
amplitude
closer
to
the
soma
is
actually
the
other
way
around,
which
is
not
to
be
confused
with
the
fact
that
this
is
still
an
excitatory
current.
So
if
you
were
to
record
the
the
intracellular
membrane
potential,
of
course,
an
excitation
at
the
synapse
will
have
a
positive
effect
throughout
the
cell
internally,
but
the
field
effect
is
different
because
you
have
an
extra
cellular,
ionic
flux.
A
F
A
Importantly,
figure
to
see
which
is
sort
of
the
opposite
of
this.
This
is
inhibition
so
and
in
this
case
there
don't
use
stimulating
current,
but
they
simply
make
basket
cells
fire
near
a
pyramidal
neuron
in
hippocampus.
And
what
you
see
is
that
because,
as
you
probably
know,
these
pasta
Purcell's
tend
to
provide
para
somatic
inhibitions
like
very
close
to
the
soma
and
when
you
record
the
field
potential
across
the
depth
of
this
neuron.
So
you
can
imagine
a
long
long,
needle
with
lots
of
electrodes
along
the
step
passing
by
the
neuron.
A
B
A
E
A
So
the
staff
that
is
close
to
the
site,
where
you
inhibit,
sees
a
positive
deflection
of
the
field
potential
where
it's
far
away.
You
see
the
return
current
because,
of
course,
the
neuron
is
internally
connected
and
somehow
a
charge
needs
needs
to
come
from
somewhere.
So
that
is
just
to
show
that
these
neurons
form
poles
right,
dipole,
quadrupole,
and
so
that
the
geometry
is
important,
particularly
when
it
comes
to
this
effect
of
the
synaptic
membrane.
F
Just
going
back
to
the
sodium
spike,
you
mentioned
earlier
large
effect,
where
the
reason
they
say
it
doesn't
show,
because
it's
short
yes
like
less
than
two
milliseconds,
so
it's
not
like
an
action
potential
doesn't
make
a
big
effect.
It's
just
short
when
you're
averaging
out
these
things
doesn't
work
for
a
well
I'm,
just
jumping
and
you
another
clue.
This
whole
dipole
thing
doesn't
seem
to
be
very
important
in
terms
of
usefulness,
for
our
work
I'm
going
to
point
out,
they
promote
self
will.
F
F
F
A
The
question
is
across:
why
would
we
care
about
the
LP,
anyways
and
one
of
the
reasons,
but
we
kept
talking
about
the
LP
was
because
of
its
signature
defect
in
the
whole
navigation
system.
So
the
fact
that
the
whole
hippocampal
entorhinal
cortex
loop
has
light
dominant
sita
and
you
know
it
that
plays
some
role,
and
so
the
question
was,
you
know:
do
we
need
to
properly
understand
that
and
that's
how
we
originally
got
into
this
hope.
A
A
E
F
Yes
and
the
sentence
is
the
temple,
the
corner,
D
coordinated,
silent
down,
stood
nearby,
not
just
in
for
Grandma
there's
a
negative
in
the
super
granulator,
so
they're
basically
saying
there
was
an
effect
here
of
opposite
polarity
in
the
upper
layers
and
the
lower
layers
of
cortex,
and
that
was
sounded
like
that
was
a
persistent
of
fact.
It's
there
all
the
time
and
sort
of
these
up
and
down
state.
So
it's
almost
like
the
dormant
up
and
down
states.
That's
what
the
after
plant
polarization
word
is
a
long
word
for
something.
F
So
this
idea
that
the
alternating
positive
and
negative
effects
on
the
upper
and
lower
layers-
you
know-
maybe
that's
something
that
useful,
maybe
there's
different
cycling-
that
you
know
we're
doing
firing
up
here,
don't
find
idea
by
firing
up
here
in
firing
gun.
Yet
so
the
down
states
alternate
being
upper
and
lower
layers.
F
A
If
you
scroll
down
a
little
bit,
there
is
a
figure
like.
Oh,
this
is
already
interesting
just
to
quickly
look
at
it.
So
the
fact
that
that
the
theta
reverses
its
polarity
reverses
its
face,
there's
a
full
phase
reversal
along
the
depth
right
off
this
electrode.
So
this
is
just
the
rat
ca1
probe.
So
you
have
all
these
different
electrode
sites
along
that
depth,
and
you
see
that
the
field
switches
around.
F
A
F
F
At
the
between
10
and
14,
or
something
like
that
is
pretty
strong
that
that's
the
little
words
I'm
interpreting
that
because
you
might
be
seeing
this
shift
govern
artists
on
too
late,
and
so,
like
you
know,
like
moving
across
columns
on
the
cortex
or
something
like
that
right.
So
I
guess.
You
already
said
that
this
is
a
reliable
effect.
Yeah.
A
F
A
A
So
this
was
the
little
thing
that
got
mentioned
also
that
wasn't
commented
on
YouTube
so
that
these
Broca's
area,
what
so
called
the
MSS
MSTP,
is
the
medial
septal
diagonal
band
night
near
near
near
Broca's
area
and
where
this
so-called
pacemaker
neurons
as
I
say
that
in
quotation
marks,
because
that's
here
is
still
highly
contested.
But
the
idea
is
that
you
can
nicely
explained
this
reversal
of
the
polarity.
If
you
assume
that
the
pyramidal
neurons
at
C,
a1
or
driven
by
two.
A
Oscillators
one
that
drives
inhibitory
at
the
source
so
close
to
the
soma
and
one
that
is
at
the
down
at
the
dendrites
there.
There
is
an
excitatory
source
through
the
perfect
path
from
intranet
cortex
and
what
you
would
get
in
that
kind
of
a
model,
then
is
you
would
get
an
inversion
of
the
face
along
the
depth
of
this
and
you
will
get
very
nice
reliable,
theta
synchronization.
A
A
F
F
F
A
F
F
Right,
okay-
and
this
is
where
it's
talking
about
in
the
middle
of
that
paragraph-
is
a
sentence.
It
says
for
intracellular.
Depolarization
is
sufficiently
strong.
The
rezident
property
of
the
membrane
can
give
way
to
a
self-sustained
oscillation
of
the
voltage
in
oscillations
that
theta
frequency
have
been
described
exactly.
F
The
question
I'm
saying
it
was
so
it
was
in
this
previous
paper,
so
the
question
was
sort
of
curious
about
this
night
night
I
needed
to
read
more
about
this
and
said
it
always
had
her
somatic
inhibitory,
neurons
haven't
progressed
into
camera
frequency,
wasn't
it
it
wasn't
clear.
These
occur
naturally
or
under
these
experimental
conditions
where
they
they
said
you
have
to
have
sufficient.
You
know
that
you
are
saying:
there's
some
manipulating
the
neuron
to
get
these
things
to
do
this,
so
I
needed
to
be
these
papers,
but
it
wasn't
clear.
F
F
F
So
residence
is
not
self-sustaining,
oscillation!
No,
it's
not
a
cookie
to
run
well.
That
was
the
big
question.
I
guess.
The
big
question
was
that
was
a
big
distinction
where,
whether
they
do
these
things
actually
oscillate
on
their
own
or
do
they
just
have
this
resident,
which
is
like
a
preferred
frequency?
So
if
you
bang
them
they'll,
you
know
they'll
eventually
die
out,
mean
you
keep
going
by
keeping
pumping
right.
So
I
that
wasn't
clear
to
me
whether
neurons
actually
create
these
oscillations
self-sustaining
oscillations.
F
A
I
made
these
things
are
always
complicated
in
vivo,
but
what
is
well-known,
for
example,
is
that
when
you
change
these
ih
currents,
which
is
known
that
they
are
more
strong,
what
is
it
along
with
also
ventral
or
gradient
of
entry
on
cortex,
where
the
grid
scales
and
the
theta
changes?
You
can
show
that
the
these
recorded
threshold
number
oscillations
change
in
frequency
and
they.
F
And
you
had
a
bunch
of
cells
that
are
fine
connect
to
each
other.
They
will
more
likely
end
up
filing
and
firing
at
the
resonant
frequencies,
because
anyways
a
little
often
is
that
often
a
news
but
later
was
back
end
up
doing
that,
and
so
the
the
fate
of
oscillation
that
would
come
about
because
of
neurons
would
naturally
try
to
fire
together
in
that
residence,
as
opposed
to
it,
seems
less
likely.
That
would
be
a
self-sustaining
oscillation
in
the
dendrite
right.
So
I'm
gonna
go
with
that.
F
A
F
B
F
F
F
B
F
A
Thousand
eleven
cells-
hey
I,
talked
about
that
there
well
a
2011
paper
which
showed
exactly
these
properties
that
they
were
looking
for
cells
at
how
many?
Yes,
when
I'm
talking
about
my
tea
and
I,
show
the.
If
you
remember
the
vco
law,
I've
talked
about
the
fact
and
then
there's
that
they
specifically
went
out
to
find
that
speeds
up.
A
D
D
A
C
F
A
A
B
F
F
F
F
F
E
F
No
papi.
No.
We
talked
last
time
about
the
idea
that
perhaps
cortex
is
unique
in
the
fact
that
it
has
one
of
the
makes
it
different
than
the
older
temporal
regions
is
that
the
evolution
I
discovered
that
you
needed
a
way
of
adjusting
time
and
and
if
we
need
a
centralized
timing
signal
where
you
don't.
That's
Cal
its
timing
scaling.
But
you
may
not
need
that
in
the
end,
because
if
you're
mapping
out
environments,
they
generally
don't
have
to
do
a
scaling.
F
F
A
D
D
B
D
C
D
A
Mediator,
liner
cortex
as
targets,
but
not
necessarily
you
know,
cochon
with
head
Direction
cells,
but
wider
context.
It
was
yeah
because
those
targets
of
those
cells
are
then
putative
core
clear
itself.
You
know
so
that
you
ghost
was
chasing
after
the
smaller
pollicis,
which
I
would
okay,
so
yeah
I
hope
everybody's
a
little
less
confused
a
lot
of
peace.
Now
we're
done
yeah,
that's
good.