<s>
Difference	B-Algorithm
due	I-Algorithm
to	I-Algorithm
memory	I-Algorithm
(	O
Dm	B-Algorithm
)	O
indexes	O
differences	O
in	O
neural	O
activity	O
during	O
the	O
study	O
phase	O
of	O
an	O
experiment	O
for	O
items	O
that	O
subsequently	O
are	O
remembered	O
compared	O
to	O
items	O
that	O
are	O
later	O
forgotten	O
.	O
</s>
<s>
It	O
is	O
mainly	O
discussed	O
as	O
an	O
event-related	B-Algorithm
potential	I-Algorithm
(	O
ERP	O
)	O
effect	O
that	O
appears	O
in	O
studies	O
employing	O
a	O
subsequent	O
memory	O
paradigm	O
,	O
in	O
which	O
ERPs	O
are	O
recorded	O
when	O
a	O
participant	O
is	O
studying	O
a	O
list	O
of	O
materials	O
and	O
trials	O
are	O
sorted	O
as	O
a	O
function	O
of	O
whether	O
they	O
go	O
on	O
to	O
be	O
remembered	O
or	O
not	O
in	O
the	O
test	O
phase	O
.	O
</s>
<s>
This	O
paper	O
looked	O
at	O
a	O
subset	O
of	O
the	O
participants	O
 '	O
ERPs	O
at	O
the	O
study	O
phase	O
and	O
found	O
those	O
trials	O
subsequently	O
remembered	O
had	O
a	O
more	O
positive	O
waveform	O
in	O
the	O
time	O
range	O
of	O
the	O
late	B-Algorithm
positive	I-Algorithm
complex	I-Algorithm
(	O
LPC	B-Algorithm
)	O
,	O
approximately	O
450	O
–	O
750	O
ms	O
after	O
stimulus	O
presentation	O
.	O
</s>
<s>
In	O
the	O
early	O
and	O
mid	O
1980s	O
,	O
several	O
studies	O
noted	O
modulation	O
of	O
the	O
P300	B-Algorithm
(	O
P3b	B-Algorithm
)	O
component	O
due	O
to	O
subsequent	O
memory	O
,	O
with	O
items	O
that	O
are	O
remembered	O
having	O
a	O
larger	O
amplitude	O
.	O
</s>
<s>
In	O
1987	O
,	O
Paller	O
,	O
Kutas	O
and	O
Mayes	O
,	O
consistent	O
with	O
previous	O
reports	O
,	O
observed	O
that	O
subsequently	O
remembered	O
items	O
elicited	O
more	O
positivity	O
in	O
the	O
later	O
portions	O
of	O
the	O
waveform	O
compared	O
to	O
items	O
later	O
forgotten	O
;	O
they	O
termed	O
these	O
observed	O
differences	O
at	O
the	O
study	O
phase	O
as	O
"	O
the	O
difference	B-Algorithm
due	I-Algorithm
to	I-Algorithm
memory	I-Algorithm
"	O
or	O
Dm	B-Algorithm
effect	O
.	O
</s>
<s>
Since	O
this	O
seminal	O
paper	O
by	O
Paller	O
,	O
Kutas	O
and	O
Mayes	O
,	O
a	O
wealth	O
of	O
research	O
using	O
ERPs	O
has	O
been	O
conducted	O
using	O
the	O
Dm	B-Algorithm
effect	O
and	O
detailing	O
the	O
multitude	O
of	O
factors	O
that	O
influence	O
the	O
manifestation	O
of	O
the	O
Dm	B-Algorithm
and	O
,	O
by	O
inference	O
,	O
encoding	O
success	O
.	O
</s>
<s>
Additionally	O
,	O
the	O
Dm	B-Algorithm
has	O
been	O
studied	O
using	O
intracranial	O
recordings	O
and	O
in	O
a	O
variety	O
of	O
functional	B-Algorithm
magnetic	I-Algorithm
resonance	I-Algorithm
imaging	I-Algorithm
(	O
fMRI	B-Algorithm
)	O
studies	O
.	O
</s>
<s>
Overwhelmingly	O
,	O
the	O
paradigm	O
used	O
to	O
elicit	O
a	O
Dm	B-Algorithm
effect	O
in	O
ERPs	O
has	O
been	O
the	O
"	O
subsequent	O
memory	O
paradigm.	O
"	O
</s>
<s>
In	O
the	O
study	O
phase	O
,	O
a	O
series	O
of	O
items	O
is	O
displayed	O
to	O
the	O
participant	O
,	O
usually	O
one	O
at	O
a	O
time	O
;	O
these	O
items	O
are	O
most	O
often	O
words	O
but	O
pictures	O
and	O
abstract	O
figures	O
have	O
also	O
been	O
used	O
(	O
though	O
with	O
less	O
consistent	O
Dm	B-Algorithm
effects	O
;	O
see	O
"	O
Functional	O
Sensitivity	O
"	O
)	O
.	O
</s>
<s>
Critically	O
for	O
the	O
Dm	B-Algorithm
effect	O
,	O
the	O
responses	O
a	O
participant	O
makes	O
to	O
the	O
old	O
items	O
in	O
the	O
test	O
phase	O
are	O
used	O
to	O
backsort	O
trials	O
in	O
the	O
study	O
phase	O
as	O
either	O
"	O
subsequently	O
remembered	O
"	O
or	O
"	O
subsequently	O
forgotten.	O
"	O
</s>
<s>
The	O
neural	O
activity	O
elicited	O
by	O
the	O
first	O
presentation	O
of	O
"	O
car	O
"	O
and	O
"	O
frog	O
"	O
at	O
the	O
study	O
phase	O
is	O
then	O
compared	O
and	O
the	O
Dm	B-Algorithm
effect	O
is	O
derived	O
from	O
this	O
comparison	O
.	O
</s>
<s>
A	O
"	O
continuous	O
recognition	O
paradigm	O
"	O
has	O
also	O
been	O
known	O
to	O
elicit	O
a	O
Dm	B-Algorithm
effect	O
.	O
</s>
<s>
The	O
neural	O
activity	O
for	O
subsequently	O
remembered	O
and	O
forgotten	O
trials	O
is	O
then	O
compared	O
for	O
the	O
first	O
presentation	O
of	O
the	O
items	O
,	O
and	O
a	O
Dm	B-Algorithm
effect	O
is	O
computed	O
.	O
</s>
<s>
Broadly	O
speaking	O
,	O
the	O
Dm	B-Algorithm
ERP	O
effect	O
is	O
any	O
difference	O
in	O
neural	O
activity	O
recorded	O
during	O
the	O
study	O
phase	O
of	O
an	O
experiment	O
that	O
differentiates	O
subsequently	O
remembered	O
items	O
and	O
subsequently	O
forgotten	O
items	O
.	O
</s>
<s>
The	O
timing	O
of	O
this	O
enhanced	O
positivity	O
suggests	O
that	O
the	O
Dm	B-Algorithm
may	O
be	O
a	O
modulation	O
of	O
several	O
ERP	O
components	O
,	O
including	O
the	O
N400	B-Algorithm
component	O
,	O
with	O
subsequently	O
remembered	O
items	O
eliciting	O
a	O
less	O
negative	O
amplitude	O
,	O
as	O
well	O
as	O
the	O
P300	B-Algorithm
or	O
an	O
LPC	B-Algorithm
,	O
where	O
items	O
that	O
are	O
later	O
remembered	O
yield	O
a	O
more	O
positive	O
amplitude	O
in	O
this	O
waveform	O
.	O
</s>
<s>
In	O
terms	O
of	O
scalp	O
topography	O
,	O
the	O
Dm	B-Algorithm
effect	O
is	O
generally	O
largest	O
over	O
centro-parietal	O
recording	O
sites	O
.	O
</s>
<s>
However	O
,	O
a	O
Dm	B-Algorithm
effect	O
with	O
a	O
more	O
anterior	O
distribution	O
can	O
be	O
observed	O
by	O
varying	O
the	O
instructions	O
participants	O
receive	O
;	O
this	O
is	O
discussed	O
further	O
below	O
.	O
</s>
<s>
The	O
canonical	O
characteristics	O
described	O
above	O
of	O
the	O
Dm	B-Algorithm
effect	O
give	O
a	O
general	O
description	O
of	O
the	O
component	O
;	O
however	O
,	O
the	O
strength	O
,	O
timing	O
,	O
topographical	O
distribution	O
and	O
even	O
whether	O
or	O
not	O
the	O
effect	O
is	O
seen	O
is	O
sensitive	O
to	O
a	O
variety	O
of	O
experimental	O
manipulations	O
.	O
</s>
<s>
A	O
large	O
number	O
of	O
Dm	B-Algorithm
ERP	O
studies	O
employ	O
an	O
incidental	O
encoding	O
approach	O
to	O
the	O
subsequent	O
memory	O
paradigm	O
.	O
</s>
<s>
This	O
was	O
the	O
approach	O
used	O
by	O
Paller	O
,	O
Kutas	O
and	O
Mayes	O
in	O
the	O
first	O
Dm	B-Algorithm
study	O
,	O
and	O
this	O
technique	O
reliably	O
elicits	O
a	O
Dm	B-Algorithm
effect	O
.	O
</s>
<s>
Several	O
studies	O
have	O
indeed	O
recorded	O
a	O
Dm	B-Algorithm
effect	O
using	O
intentional	O
encoding	O
instructions	O
,	O
but	O
this	O
effect	O
sometimes	O
differs	O
from	O
the	O
Dm	B-Algorithm
effect	O
from	O
incidental	O
encoding	O
.	O
</s>
<s>
In	O
a	O
direct	O
comparison	O
of	O
incidental	O
vs.	O
intentional	O
encoding	O
,	O
Munte	O
et	O
al.	O
,	O
(	O
1988	O
)	O
found	O
a	O
stronger	O
Dm	B-Algorithm
effect	O
for	O
the	O
incidental	O
encoding	O
condition	O
.	O
</s>
<s>
Moreover	O
,	O
the	O
Dm	B-Algorithm
effect	O
for	O
the	O
intentional	O
encoding	O
condition	O
appeared	O
later	O
than	O
the	O
Dm	B-Algorithm
for	O
incidental	O
encoding	O
,	O
and	O
also	O
showed	O
a	O
more	O
frontal	O
topography	O
compared	O
to	O
the	O
centro-parietal	O
distribution	O
observed	O
in	O
incidental	O
encoding	O
.	O
</s>
<s>
This	O
is	O
also	O
reflected	O
in	O
the	O
Dm	B-Algorithm
effect	O
.	O
</s>
<s>
The	O
Dm	B-Algorithm
effect	O
for	O
words	O
encoded	O
in	O
a	O
semantic	O
fashion	O
was	O
more	O
positive	O
than	O
the	O
Dm	B-Algorithm
effect	O
observed	O
for	O
words	O
non-semantically	O
encoded	O
.	O
</s>
<s>
It	O
is	O
important	O
to	O
note	O
that	O
a	O
Dm	B-Algorithm
effect	O
can	O
be	O
seen	O
for	O
shallower	O
processing	O
as	O
well	O
,	O
as	O
was	O
the	O
case	O
in	O
one	O
of	O
the	O
shallow	O
processing	O
tasks	O
in	O
the	O
Paller	O
,	O
Kutas	O
and	O
Mayes	O
(	O
1987	O
)	O
paper	O
,	O
as	O
well	O
as	O
in	O
Friedman	O
,	O
Ritter	O
and	O
Snodgrass	O
(	O
1996	O
)	O
.	O
</s>
<s>
found	O
that	O
both	O
recognition	O
memory	O
as	O
well	O
as	O
the	O
Dm	B-Algorithm
effect	O
was	O
larger	O
for	O
pairs	O
of	O
words	O
that	O
were	O
relationally	O
encoded	O
(	O
e.g.	O
</s>
<s>
This	O
further	O
suggests	O
that	O
the	O
Dm	B-Algorithm
effect	O
may	O
be	O
enhanced	O
when	O
items	O
are	O
encoded	O
on	O
a	O
semantic	O
level	O
.	O
</s>
<s>
Also	O
,	O
the	O
Dm	B-Algorithm
effect	O
seems	O
sensitive	O
to	O
the	O
type	O
of	O
rehearsal	O
strategies	O
a	O
participant	O
performs	O
.	O
</s>
<s>
Specifically	O
,	O
Fabiani	O
,	O
Karis	O
and	O
Donchin	O
found	O
that	O
P300	B-Algorithm
modulation	O
at	O
encoding	O
(	O
particularly	O
for	O
"	O
isolates	O
"	O
,	O
stimuli	O
presented	O
in	O
a	O
deviant	O
font	O
relative	O
to	O
all	O
other	O
stimuli	O
)	O
correlated	O
with	O
later	O
memory	O
for	O
subjects	O
who	O
engaged	O
in	O
rote	O
rehearsal	O
(	O
such	O
as	O
simply	O
repeating	O
the	O
word	O
in	O
one	O
's	O
head	O
)	O
but	O
not	O
for	O
those	O
who	O
undertook	O
elaborative	O
rehearsal	O
,	O
which	O
emphasizes	O
linking	O
the	O
current	O
word	O
to	O
other	O
words	O
presented	O
and	O
pre-existing	O
knowledge	O
.	O
</s>
<s>
The	O
Dm	B-Algorithm
effect	O
has	O
been	O
shown	O
to	O
be	O
sensitive	O
to	O
how	O
participants	O
are	O
asked	O
to	O
display	O
their	O
memory	O
for	O
previous	O
items	O
.	O
</s>
<s>
In	O
a	O
1988	O
paper	O
by	O
Paller	O
,	O
McCarthy	O
and	O
Wood	O
,	O
a	O
greater	O
Dm	B-Algorithm
effect	O
was	O
observed	O
for	O
items	O
that	O
were	O
freely	O
recalled	O
with	O
no	O
external	O
cues	O
,	O
compared	O
to	O
items	O
that	O
were	O
presented	O
and	O
the	O
subject	O
was	O
asked	O
if	O
he	O
or	O
she	O
recognizes	O
the	O
item	O
as	O
old	O
.	O
</s>
<s>
This	O
is	O
suggestive	O
of	O
the	O
Dm	B-Algorithm
effect	O
being	O
larger	O
for	O
stronger	O
representations	O
,	O
as	O
recall	O
is	O
generally	O
more	O
difficult	O
than	O
recognition	O
.	O
</s>
<s>
In	O
a	O
similar	O
vein	O
,	O
Friedman	O
&	O
Trott	O
(	O
2000	O
)	O
found	O
that	O
young	O
adult	O
participants	O
displayed	O
a	O
robust	O
Dm	B-Algorithm
effect	O
when	O
they	O
not	O
only	O
remembered	O
seeing	O
a	O
word	O
,	O
but	O
could	O
also	O
remember	O
some	O
details	O
of	O
the	O
context	O
of	O
when	O
it	O
was	O
presented	O
.	O
</s>
<s>
In	O
comparison	O
,	O
a	O
Dm	B-Algorithm
effect	O
for	O
items	O
that	O
were	O
subsequently	O
judged	O
as	O
old	O
,	O
but	O
only	O
from	O
a	O
general	O
sense	O
of	O
familiarity	O
,	O
did	O
not	O
emerge	O
.	O
</s>
<s>
A	O
Dm	B-Algorithm
effect	O
was	O
found	O
in	O
both	O
conditions	O
for	O
older	O
adults	O
.	O
</s>
<s>
A	O
host	O
of	O
studies	O
have	O
found	O
a	O
Dm	B-Algorithm
effect	O
when	O
presenting	O
words	O
as	O
stimuli	O
.	O
</s>
<s>
However	O
,	O
experiments	O
using	O
pictures	O
or	O
abstract	O
figures	O
have	O
found	O
less	O
consistent	O
Dm	B-Algorithm
effects	O
.	O
</s>
<s>
Experiments	O
using	O
a	O
continuous	O
recognition	O
paradigm	O
have	O
found	O
a	O
Dm	B-Algorithm
effect	O
for	O
pictures	O
of	O
everyday	O
objects	O
.	O
</s>
<s>
Van	O
Petten	O
and	O
Senkfor	O
(	O
1996	O
)	O
did	O
not	O
find	O
a	O
Dm	B-Algorithm
effect	O
when	O
they	O
presented	O
participants	O
with	O
abstract	O
drawings	O
;	O
however	O
,	O
a	O
Dm	B-Algorithm
effect	O
was	O
observed	O
in	O
the	O
same	O
group	O
of	O
participants	O
when	O
words	O
were	O
used	O
as	O
stimuli	O
.	O
</s>
<s>
Coupling	O
the	O
results	O
of	O
Dm	B-Algorithm
effects	O
for	O
words	O
and	O
common	O
pictures	O
and	O
the	O
lack	O
of	O
Dm	B-Algorithm
effects	O
for	O
abstract	O
figures	O
suggests	O
the	O
Dm	B-Algorithm
effect	O
may	O
be	O
contingent	O
on	O
using	O
meaningful	O
stimuli	O
or	O
some	O
pre-existing	O
knowledge	O
of	O
the	O
stimuli	O
.	O
</s>
<s>
In	O
an	O
elegant	O
report	O
by	O
Gonsalves	O
and	O
Paller	O
(	O
2000	O
)	O
,	O
the	O
Dm	B-Algorithm
effect	O
was	O
found	O
to	O
be	O
greater	O
for	O
false	O
memories	O
compared	O
to	O
correctly	O
classified	O
memories	O
.	O
</s>
