<s>
The	O
P600	B-Algorithm
is	O
an	O
event-related	B-Algorithm
potential	I-Algorithm
(	O
ERP	O
)	O
component	O
,	O
or	O
peak	O
in	O
electrical	O
brain	B-Application
activity	I-Application
measured	O
by	O
electroencephalography	B-Application
(	O
EEG	B-Application
)	O
.	O
</s>
<s>
It	O
is	O
a	O
language-relevant	O
ERP	O
component	O
and	O
is	O
thought	O
to	O
be	O
elicited	O
by	O
hearing	O
or	O
reading	O
grammatical	O
errors	O
and	O
other	O
syntactic	B-Application
anomalies	O
.	O
</s>
<s>
The	O
P600	B-Algorithm
can	O
be	O
elicited	O
in	O
both	O
visual	O
(	O
reading	O
)	O
and	O
auditory	O
(	O
listening	O
)	O
experiments	O
,	O
and	O
is	O
characterized	O
as	O
a	O
positive-going	O
deflection	O
with	O
an	O
onset	O
around	O
500	O
milliseconds	O
after	O
the	O
stimulus	O
that	O
elicits	O
it	O
;	O
it	O
often	O
reaches	O
its	O
peak	O
around	O
600	O
milliseconds	O
after	O
presentation	O
of	O
the	O
stimulus	O
(	O
hence	O
its	O
name	O
)	O
,	O
and	O
lasts	O
several	O
hundred	O
milliseconds	O
.	O
</s>
<s>
In	O
other	O
words	O
,	O
in	O
the	O
EEG	B-Application
waveform	O
it	O
is	O
a	O
large	O
peak	O
in	O
the	O
positive	O
direction	O
,	O
which	O
starts	O
around	O
500	O
milliseconds	O
after	O
the	O
subject	O
sees	O
or	O
hears	O
a	O
stimulus	O
.	O
</s>
<s>
It	O
is	O
typically	O
thought	O
of	O
as	O
appearing	O
mostly	O
on	O
centro-parietal	O
electrodes	O
(	O
i.e.	O
,	O
over	O
the	O
posterior	O
part	O
of	O
the	O
center	O
of	O
the	O
scalp	O
)	O
,	O
but	O
frontal	O
P600s	B-Algorithm
have	O
also	O
been	O
observed	O
in	O
several	O
studies	O
.	O
</s>
<s>
In	O
EEG	B-Application
,	O
however	O
,	O
this	O
distribution	O
at	O
the	O
scalp	O
does	O
not	O
mean	O
the	O
P600	B-Algorithm
is	O
coming	O
from	O
that	O
part	O
of	O
the	O
brain	O
;	O
a	O
2007	O
study	O
using	O
magnetoencephalography	B-Algorithm
(	O
MEG	O
)	O
speculates	O
that	O
the	O
generators	O
of	O
the	O
P600	B-Algorithm
are	O
in	O
the	O
posterior	O
temporal	O
lobe	O
,	O
behind	O
Wernicke	O
's	O
area	O
.	O
</s>
<s>
The	O
P600	B-Algorithm
was	O
first	O
reported	O
by	O
Lee	O
Osterhout	O
and	O
Phillip	O
Holcomb	O
in	O
1992	O
.	O
</s>
<s>
It	O
is	O
also	O
sometimes	O
called	O
the	O
syntactic	B-Algorithm
positive	I-Algorithm
shift	I-Algorithm
(	O
SPS	O
)	O
,	O
since	O
it	O
has	O
a	O
positive	O
polarity	O
and	O
is	O
usually	O
elicited	O
by	O
syntactic	B-Application
phenomena	O
.	O
</s>
<s>
The	O
P600	B-Algorithm
was	O
originally	O
considered	O
a	O
"	O
syntactic	B-Application
"	O
ERP	O
component	O
,	O
as	O
it	O
is	O
elicited	O
by	O
several	O
types	O
of	O
syntactic	B-Application
phenomena	O
,	O
including	O
ungrammatical	O
stimuli	O
,	O
garden-path	O
sentences	O
that	O
require	O
reanalysis	O
,	O
complex	O
sentences	O
with	O
a	O
large	O
number	O
of	O
thematic	O
roles	O
,	O
and	O
the	O
processing	O
of	O
filler-gap	O
dependencies	O
(	O
such	O
as	O
wh-words	O
that	O
appear	O
at	O
the	O
beginning	O
of	O
a	O
sentence	O
in	O
English	O
but	O
are	O
actually	O
interpreted	O
somewhere	O
else	O
)	O
.	O
</s>
<s>
A	O
P600	B-Algorithm
may	O
be	O
elicited	O
by	O
several	O
kinds	O
of	O
grammatical	O
errors	O
in	O
sentences	O
,	O
such	O
as	O
problems	O
in	O
agreement	O
,	O
such	O
as	O
"	O
the	O
child	O
*	O
throw	O
the	O
toy	O
"	O
.	O
</s>
<s>
In	O
addition	O
to	O
this	O
sort	O
of	O
subject-verb	O
disagreement	O
,	O
P600s	B-Algorithm
have	O
also	O
been	O
elicited	O
by	O
disagreements	O
in	O
tense	O
,	O
gender	O
,	O
number	O
,	O
and	O
case	O
,	O
as	O
well	O
as	O
phrase	O
structure	O
violations	O
.	O
</s>
<s>
A	O
2009	O
study	O
has	O
suggested	O
that	O
these	O
errors	O
elicit	O
stronger	O
P600s	B-Algorithm
than	O
the	O
other	O
syntactic	B-Application
stimuli	O
that	O
have	O
been	O
implicated	O
.	O
</s>
<s>
P600s	B-Algorithm
are	O
also	O
known	O
to	O
occur	O
when	O
a	O
sentence	O
contains	O
no	O
outright	O
grammatical	O
error	O
,	O
but	O
must	O
be	O
parsed	O
in	O
a	O
different	O
way	O
than	O
the	O
reader	O
originally	O
expects	O
.	O
</s>
<s>
For	O
example	O
,	O
found	O
P600s	B-Algorithm
elicited	O
by	O
the	O
word	O
to	O
in	O
sentences	O
such	O
as	O
The	O
broker	O
persuaded	O
to	O
sell	O
the	O
stock	O
was	O
tall	O
.	O
</s>
<s>
P600s	B-Algorithm
are	O
also	O
elicited	O
by	O
errors	O
in	O
musical	O
harmony	O
,	O
such	O
as	O
when	O
a	O
chord	O
is	O
played	O
out	O
of	O
key	O
with	O
the	O
rest	O
of	O
a	O
musical	O
phrase	O
.	O
</s>
<s>
This	O
implies	O
that	O
P600s	B-Algorithm
are	O
not	O
"	O
language-specific	O
,	O
"	O
but	O
"	O
can	O
be	O
elicited	O
in	O
nonlinguistic	O
(	O
but	O
rule-governed	O
)	O
sequences.	O
"	O
</s>
<s>
Some	O
studies	O
have	O
found	O
a	O
P600	B-Algorithm
elicited	O
by	O
words	O
where	O
there	O
is	O
no	O
grammatical	O
error	O
and	O
no	O
"	O
garden	O
path	O
"	O
(	O
i.e.	O
,	O
where	O
the	O
word	O
is	O
exactly	O
what	O
the	O
reader	O
would	O
expect	O
)	O
,	O
but	O
when	O
the	O
sentence	O
is	O
complex	O
because	O
there	O
are	O
a	O
number	O
of	O
noun	O
phrases	O
active	O
.	O
</s>
<s>
"	O
)	O
;	O
several	O
studies	O
have	O
found	O
that	O
after	O
the	O
reader	O
sees	O
the	O
word	O
imitate	O
he	O
or	O
she	O
has	O
a	O
P600	B-Algorithm
response	O
,	O
possibly	O
as	O
a	O
result	O
of	O
re-activating	O
who	O
.	O
</s>
<s>
These	O
sorts	O
of	O
P600s	B-Algorithm
get	O
stronger	O
as	O
the	O
number	O
of	O
noun	O
phrases	O
active	O
in	O
the	O
sentences	O
increases	O
,	O
suggesting	O
that	O
the	O
P600	B-Algorithm
generator	O
is	O
sensitive	O
to	O
the	O
level	O
of	O
complexity	O
in	O
a	O
sentence	O
.	O
</s>
<s>
demonstrated	O
a	O
so-called	O
"	O
semantic	O
P600	B-Algorithm
"	O
in	O
sentences	O
that	O
are	O
grammatically	O
correct	O
but	O
semantically	O
anomalous	O
,	O
and	O
in	O
which	O
syntactic	B-Application
reanalysis	O
is	O
more	O
appealing	O
than	O
semantic	O
reanalysis	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
P600	B-Algorithm
may	O
be	O
elicited	O
in	O
the	O
following	O
sentence	O
:	O
The	O
hearty	O
meal	O
was	O
devouring	O
the	O
kids.This	O
suggests	O
that	O
the	O
reader	O
would	O
rather	O
interpret	O
the	O
sentence	O
as	O
containing	O
a	O
morphosyntactic	O
error	O
(	O
saying	O
"	O
devouring	O
"	O
instead	O
of	O
"	O
devoured	O
by	O
"	O
)	O
rather	O
than	O
a	O
semantic	O
one	O
(	O
meals	O
ca	O
n't	O
devour	O
kids	O
,	O
but	O
can	O
be	O
devoured	O
by	O
them	O
)	O
.	O
</s>
<s>
The	O
interpretation	O
of	O
"	O
semantic	O
P600s	B-Algorithm
"	O
has	O
attracted	O
considerable	O
attention	O
and	O
controversy	O
in	O
the	O
literature	O
.	O
</s>
<s>
There	O
are	O
several	O
theories	O
about	O
what	O
computational	O
processes	O
the	O
P600	B-Algorithm
may	O
be	O
triggered	O
by	O
.	O
</s>
<s>
Because	O
it	O
often	O
happens	O
in	O
response	O
to	O
grammatical	O
violations	O
or	O
garden	O
path	O
sentences	O
,	O
one	O
theory	O
is	O
that	O
the	O
P600	B-Algorithm
reflects	O
processes	O
of	O
revision	O
(	O
i.e.	O
,	O
trying	O
to	O
"	O
rescue	O
"	O
the	O
interpretation	O
of	O
a	O
sentence	O
that	O
ca	O
n't	O
be	O
processed	O
normally	O
because	O
of	O
structural	O
errors	O
)	O
and	O
reanalysis	O
(	O
i.e.	O
,	O
trying	O
to	O
rearrange	O
the	O
structure	O
of	O
a	O
sentence	O
that	O
has	O
been	O
interpreted	O
incorrectly	O
because	O
of	O
a	O
garden	O
path	O
)	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
other	O
models	O
suggest	O
that	O
the	O
P600	B-Algorithm
may	O
not	O
reflect	O
these	O
processes	O
in	O
particular	O
,	O
but	O
just	O
the	O
amount	O
of	O
time	O
and	O
effort	O
in	O
general	O
it	O
takes	O
to	O
build	O
up	O
coherent	O
structure	O
in	O
a	O
sentence	O
,	O
or	O
the	O
general	O
processes	O
of	O
creating	O
or	O
destroying	O
syntactic	B-Application
structure	O
(	O
not	O
specifically	O
because	O
of	O
repair	O
)	O
.	O
</s>
<s>
Another	O
proposal	O
is	O
that	O
the	O
P600	B-Algorithm
does	O
not	O
necessarily	O
reflect	O
any	O
linguistic	O
processes	O
per	O
se	O
,	O
but	O
is	O
similar	O
to	O
the	O
P300	B-Algorithm
in	O
that	O
it	O
is	O
triggered	O
when	O
a	O
subject	O
encounters	O
"	O
improbable	O
"	O
stimulisince	O
ungrammatical	O
sentences	O
are	O
relatively	O
rare	O
in	O
natural	O
speech	O
,	O
a	O
P600	B-Algorithm
may	O
not	O
be	O
a	O
linguistic	O
response	O
but	O
simply	O
an	O
effect	O
of	O
the	O
subject	O
's	O
"	O
surprise	O
"	O
upon	O
encountering	O
an	O
unexpected	O
stimulus	O
.	O
</s>
<s>
Another	O
account	O
is	O
that	O
the	O
P600	B-Algorithm
reflects	O
error/surprisal	O
propagation	O
due	O
to	O
learning	O
processes	O
that	O
take	O
place	O
during	O
linguistic	O
adaptation	O
and	O
this	O
account	O
has	O
been	O
implemented	O
in	O
a	O
connectionist	O
model	O
that	O
explains	O
several	O
P600/N400	O
results	O
.	O
</s>
