<s>
In	O
neuroscience	O
,	O
the	O
N100	B-Algorithm
or	O
N1	B-Algorithm
is	O
a	O
large	O
,	O
negative-going	O
evoked	B-Algorithm
potential	I-Algorithm
measured	O
by	O
electroencephalography	B-Application
(	O
its	O
equivalent	O
in	O
magnetoencephalography	B-Algorithm
is	O
the	O
M100	B-Algorithm
)	O
;	O
it	O
peaks	O
in	O
adults	O
between	O
80	O
and	O
120	O
milliseconds	O
after	O
the	O
onset	O
of	O
a	O
stimulus	O
,	O
and	O
is	O
distributed	O
mostly	O
over	O
the	O
fronto-central	O
region	O
of	O
the	O
scalp	O
.	O
</s>
<s>
It	O
is	O
often	O
referred	O
to	O
with	O
the	O
following	O
P200	B-Algorithm
evoked	B-Algorithm
potential	I-Algorithm
as	O
the	O
"	O
N100-P200	O
"	O
or	O
"	O
N1-P2	O
"	O
complex	O
.	O
</s>
<s>
While	O
most	O
research	O
focuses	O
on	O
auditory	O
stimuli	O
,	O
the	O
N100	B-Algorithm
also	O
occurs	O
for	O
visual	O
(	O
see	O
visual	B-Algorithm
N1	I-Algorithm
,	O
including	O
an	O
illustration	O
)	O
,	O
olfactory	O
,	O
heat	O
,	O
pain	O
,	O
balance	O
,	O
respiration	O
blocking	O
,	O
and	O
somatosensory	O
stimuli	O
.	O
</s>
<s>
The	O
auditory	O
N100	B-Algorithm
is	O
generated	O
by	O
a	O
network	O
of	O
neural	O
populations	O
in	O
the	O
primary	O
and	O
association	O
auditory	O
cortices	O
in	O
the	O
superior	O
temporal	O
gyrus	O
in	O
Heschl	O
's	O
gyrus	O
and	O
planum	O
temporale	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
is	O
preattentive	O
and	O
involved	O
in	O
perception	O
because	O
its	O
amplitude	B-Application
is	O
strongly	O
dependent	O
upon	O
such	O
things	O
as	O
the	O
rise	O
time	O
of	O
the	O
onset	O
of	O
a	O
sound	O
,	O
its	O
loudness	O
,	O
interstimulus	O
interval	O
with	O
other	O
sounds	O
,	O
and	O
the	O
comparative	O
frequency	O
of	O
a	O
sound	O
as	O
its	O
amplitude	B-Application
increases	O
in	O
proportion	O
to	O
how	O
much	O
a	O
sound	O
differs	O
in	O
frequency	O
from	O
a	O
preceding	O
one	O
.	O
</s>
<s>
Neuromagnetic	B-Algorithm
research	O
has	O
linked	O
it	O
further	O
to	O
perception	O
by	O
finding	O
that	O
the	O
auditory	O
cortex	O
has	O
a	O
tonotopic	O
organization	O
to	O
N100	B-Algorithm
.	O
</s>
<s>
N100	B-Algorithm
is	O
decreased	O
when	O
a	O
person	O
controls	O
the	O
creation	O
of	O
auditory	O
stimuli	O
,	O
such	O
as	O
their	O
own	O
voice	O
.	O
</s>
<s>
There	O
are	O
three	O
subtypes	O
of	O
adult	O
auditory	O
N100	B-Algorithm
.	O
</s>
<s>
N100b	O
or	O
vertex	O
N100	B-Algorithm
,	O
peaking	O
at	O
100	O
ms.	O
</s>
<s>
The	O
two	O
T-complex	O
N100	B-Algorithm
evoked	B-Algorithm
potentials	I-Algorithm
are	O
created	O
by	O
auditory	O
association	O
cortices	O
in	O
the	O
superior	O
temporal	O
gyri	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
is	O
often	O
known	O
as	O
the	O
"	O
auditory	O
N100	B-Algorithm
"	O
because	O
it	O
is	O
elicited	O
by	O
perception	O
of	O
auditory	O
stimuli	O
.	O
</s>
<s>
During	O
stage	O
2	O
NREM	O
it	O
seems	O
responsible	O
for	O
the	O
production	O
of	O
K-complexes	B-Algorithm
.	O
</s>
<s>
N100	B-Algorithm
is	O
reduced	O
following	O
total	O
sleep	O
deprivation	O
and	O
this	O
associates	O
with	O
an	O
impaired	O
ability	O
to	O
consolidate	O
memories	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
depends	O
upon	O
unpredictability	O
of	O
stimulus	O
:	O
it	O
is	O
weaker	O
when	O
stimuli	O
are	O
repetitive	O
,	O
and	O
stronger	O
when	O
they	O
are	O
random	O
.	O
</s>
<s>
When	O
subjects	O
are	O
allowed	O
to	O
control	O
stimuli	O
,	O
using	O
a	O
switch	O
,	O
the	O
N100	B-Algorithm
may	O
decrease	O
.	O
</s>
<s>
This	O
effect	O
has	O
been	O
linked	O
to	O
intelligence	O
,	O
as	O
the	O
N100	B-Algorithm
attenuation	O
for	O
self-controlled	O
stimuli	O
occurs	O
the	O
most	O
strongly	O
(	O
i.e.	O
,	O
the	O
N100	B-Algorithm
shrinks	O
the	O
most	O
)	O
in	O
individuals	O
who	O
are	O
also	O
evaluated	O
as	O
having	O
high	O
intelligence	O
.	O
</s>
<s>
Indeed	O
,	O
researchers	O
have	O
found	O
that	O
in	O
those	O
with	O
Down	O
syndrome	O
"	O
the	O
amplitude	B-Application
of	O
the	O
self-evoked	O
response	O
actually	O
exceeded	O
that	O
of	O
the	O
machine-evoked	O
potential	O
"	O
.	O
</s>
<s>
Being	O
warned	O
about	O
an	O
upcoming	O
stimulus	O
also	O
reduces	O
its	O
N100	B-Algorithm
.	O
</s>
<s>
The	O
amplitude	B-Application
of	O
N100	B-Algorithm
shows	O
refractoriness	O
upon	O
repetition	O
of	O
a	O
stimulus	O
;	O
in	O
other	O
words	O
,	O
it	O
decreases	O
at	O
first	O
upon	O
repeated	O
presentations	O
of	O
the	O
stimulus	O
,	O
but	O
after	O
a	O
short	O
period	O
of	O
silence	O
it	O
returns	O
to	O
its	O
previous	O
level	O
.	O
</s>
<s>
Paradoxically	O
,	O
at	O
short	O
repetition	O
the	O
second	O
N100	B-Algorithm
is	O
enhanced	O
both	O
for	O
sound	O
and	O
somatosensory	O
stimuli	O
.	O
</s>
<s>
With	O
paired	O
clicks	O
,	O
the	O
second	O
N100	B-Algorithm
is	O
reduced	O
due	O
to	O
sensory	O
gating	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
plays	O
a	O
role	O
in	O
recognizing	O
the	O
difference	O
and	O
categorizing	O
these	O
sounds	O
:	O
speech	O
stimuli	O
with	O
a	O
short	O
0	O
to	O
+30	O
ms	O
voice	O
onset	O
time	O
evoke	O
a	O
single	O
N100	B-Algorithm
response	O
but	O
those	O
with	O
a	O
longer	O
( +30	O
ms	O
and	O
longer	O
)	O
evoked	O
two	O
N100	B-Algorithm
peaks	O
and	O
these	O
are	O
linked	O
to	O
the	O
consonant	O
release	O
and	O
vocal	O
cord	O
vibration	O
onset	O
.	O
</s>
<s>
Traditionally	O
,	O
50	O
to	O
150	O
ms	O
evoked	B-Algorithm
potentials	I-Algorithm
were	O
considered	O
too	O
short	O
to	O
be	O
influenced	O
by	O
top-down	O
influences	O
from	O
the	O
prefrontal	O
cortex	O
.	O
</s>
<s>
Research	O
also	O
finds	O
that	O
the	O
modulation	O
effects	O
upon	O
N100	B-Algorithm
are	O
affected	O
by	O
prefrontal	O
cortex	O
lesions	O
.	O
</s>
<s>
These	O
higher-level	O
areas	O
create	O
the	O
attentive	O
,	O
repetition	O
,	O
and	O
arousal	O
modulations	O
upon	O
the	O
sensory	O
area	O
processing	O
reflected	O
in	O
N100	B-Algorithm
.	O
</s>
<s>
Another	O
top-down	O
influence	O
upon	O
N100	B-Algorithm
has	O
been	O
suggested	O
to	O
be	O
efference	O
copies	O
from	O
a	O
person	O
's	O
intended	O
movements	O
so	O
that	O
the	O
stimulation	O
that	O
results	O
from	O
them	O
are	O
not	O
processed	O
.	O
</s>
<s>
A	O
person	O
's	O
own	O
voice	O
produces	O
a	O
reduced	O
N100	B-Algorithm
as	O
does	O
the	O
effect	O
of	O
a	O
self-initiated	O
compared	O
to	O
externally	O
created	O
perturbation	O
upon	O
balance	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
is	O
a	O
slow-developing	O
evoked	B-Algorithm
potential	I-Algorithm
.	O
</s>
<s>
From	O
one	O
to	O
four	O
years	O
of	O
age	O
,	O
a	O
positive	O
evoked	B-Algorithm
potential	I-Algorithm
,	O
P100	O
,	O
is	O
the	O
predominant	O
peak	O
.	O
</s>
<s>
Older	O
children	O
start	O
to	O
develop	O
a	O
negative	O
evoked	B-Algorithm
potential	I-Algorithm
at	O
200	O
ms	O
that	O
dominates	O
evoked	B-Algorithm
potentials	I-Algorithm
until	O
adolescence	O
;	O
this	O
potential	O
is	O
identical	O
to	O
the	O
adult	O
N100	B-Algorithm
in	O
scalp	O
topography	O
and	O
elicitation	O
,	O
but	O
with	O
a	O
much	O
later	O
onset	O
.	O
</s>
<s>
The	O
magnetic	O
M100	B-Algorithm
(	O
measured	O
by	O
MEG	B-Algorithm
rather	O
than	O
EEG	B-Application
)	O
is	O
,	O
likewise	O
,	O
less	O
robust	O
in	O
children	O
than	O
in	O
adults	O
.	O
</s>
<s>
An	O
adult-like	O
N100-P200	O
complex	O
only	O
develops	O
after	O
10	O
years	O
of	O
age	O
.	O
</s>
<s>
The	O
various	O
types	O
of	O
N100	B-Algorithm
mature	O
at	O
different	O
times	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
may	O
be	O
used	O
to	O
test	O
for	O
abnormalities	O
in	O
the	O
auditory	O
system	O
where	O
verbal	O
or	O
behavioral	O
responses	O
cannot	O
be	O
used	O
,	O
such	O
with	O
individuals	O
in	O
coma	O
;	O
in	O
such	O
cases	O
,	O
it	O
can	O
help	O
predict	O
the	O
probability	O
of	O
recovery	O
.	O
</s>
<s>
High	O
density	O
mapping	O
of	O
the	O
location	O
of	O
the	O
generators	O
of	O
M100	B-Algorithm
is	O
being	O
researched	O
as	O
a	O
means	O
of	O
presurgical	O
neuromapping	O
needed	O
for	O
neurosurgery	O
.	O
</s>
<s>
Many	O
cognitive	O
or	O
other	O
mental	O
impairments	O
are	O
associated	O
with	O
changes	O
in	O
the	O
N100	B-Algorithm
response	O
,	O
including	O
the	O
following	O
:	O
</s>
<s>
There	O
is	O
some	O
evidence	O
that	O
the	O
N100	B-Algorithm
is	O
affected	O
in	O
those	O
with	O
dyslexia	O
and	O
specific	O
language	O
impairment	O
.	O
</s>
<s>
The	O
sensory	O
gating	O
effect	O
upon	O
N100	B-Algorithm
with	O
paired	O
clicks	O
is	O
reduced	O
in	O
those	O
with	O
schizophrenia	B-Application
.	O
</s>
<s>
In	O
individuals	O
with	O
tinnitus	O
,	O
those	O
with	O
smaller	O
N100	B-Algorithm
are	O
less	O
distressed	O
than	O
those	O
with	O
larger	O
amplitudes	B-Application
.	O
</s>
<s>
Migraine	O
is	O
associated	O
with	O
an	O
increase	O
rather	O
than	O
decrease	O
in	O
N100	B-Algorithm
amplitude	B-Application
with	O
repetition	O
of	O
the	O
high-intensity	O
stimulation	O
.	O
</s>
<s>
The	O
N100	B-Algorithm
is	O
10	O
to	O
20%	O
larger	O
than	O
normal	O
when	O
the	O
auditory	O
stimulus	O
is	O
synchronized	O
with	O
the	O
diastolic	O
phase	O
of	O
the	O
cardiac	O
blood	O
pressure	O
pulse	O
.	O
</s>
<s>
The	O
Mismatch	B-Algorithm
negativity	I-Algorithm
(	O
MMN	O
)	O
is	O
an	O
evoked	B-Algorithm
potential	I-Algorithm
that	O
occurs	O
at	O
roughly	O
the	O
same	O
time	O
as	O
N100	B-Algorithm
in	O
response	O
to	O
rare	O
auditory	O
events	O
.	O
</s>
<s>
It	O
differs	O
from	O
the	O
N100	B-Algorithm
in	O
that	O
:	O
</s>
<s>
The	O
MMN	O
occurs	O
too	O
late	O
to	O
be	O
an	O
N100	B-Algorithm
.	O
</s>
<s>
The	O
MMN	O
,	O
unlike	O
N100	B-Algorithm
,	O
may	O
be	O
elicited	O
by	O
stimulus	O
omissions	O
(	O
i.e.	O
,	O
not	O
hearing	O
a	O
stimulus	O
when	O
you	O
expect	O
to	O
hear	O
one	O
)	O
.	O
</s>
<s>
Pauline	O
A	O
.	O
Davis	O
at	O
Harvard	O
University	O
first	O
recorded	O
the	O
wave	O
peak	O
now	O
identified	O
with	O
N100	B-Algorithm
.	O
</s>
<s>
The	O
present	O
use	O
of	O
the	O
N1	B-Algorithm
to	O
describe	O
this	O
peak	O
originates	O
in	O
1966	O
and	O
N100	B-Algorithm
later	O
in	O
the	O
mid	O
1970s	O
.	O
</s>
<s>
Due	O
to	O
magnetoencephalography	B-Algorithm
,	O
research	O
is	O
increasingly	O
done	O
upon	O
M100	B-Algorithm
,	O
the	O
magnetic	O
counterpart	O
of	O
the	O
electroencephalographic	B-Application
N100	B-Algorithm
.	O
</s>
<s>
New	O
techniques	O
,	O
such	O
as	O
event-related	O
beam-forming	O
with	O
magnetoencephalography	B-Algorithm
,	O
allow	O
sufficiently	O
accurate	O
location	O
of	O
M100	B-Algorithm
sources	O
to	O
be	O
clinically	O
useful	O
for	O
preparing	O
surgery	O
upon	O
the	O
brain	O
.	O
</s>
