<s>
ACT-R	B-Language
(	O
pronounced	O
/ˌækt	O
ˈɑr/	O
;	O
short	O
for	O
"	O
Adaptive	B-Language
Control	I-Language
of	I-Language
Thought	I-Language
—	O
Rational	O
"	O
)	O
is	O
a	O
cognitive	B-Architecture
architecture	I-Architecture
mainly	O
developed	O
by	O
John	O
Robert	O
Anderson	O
and	O
Christian	O
Lebiere	O
at	O
Carnegie	O
Mellon	O
University	O
.	O
</s>
<s>
Like	O
any	O
cognitive	B-Architecture
architecture	I-Architecture
,	O
ACT-R	B-Language
aims	O
to	O
define	O
the	O
basic	O
and	O
irreducible	O
cognitive	O
and	O
perceptual	O
operations	O
that	O
enable	O
the	O
human	O
mind	O
.	O
</s>
<s>
Most	O
of	O
the	O
ACT-R	B-Language
'	O
s	O
basic	O
assumptions	O
are	O
also	O
inspired	O
by	O
the	O
progress	O
of	O
cognitive	O
neuroscience	O
,	O
and	O
ACT-R	B-Language
can	O
be	O
seen	O
and	O
described	O
as	O
a	O
way	O
of	O
specifying	O
how	O
the	O
brain	O
itself	O
is	O
organized	O
in	O
a	O
way	O
that	O
enables	O
individual	O
processing	O
modules	O
to	O
produce	O
cognition	O
.	O
</s>
<s>
ACT-R	B-Language
has	O
been	O
inspired	O
by	O
the	O
work	O
of	O
Allen	O
Newell	O
,	O
and	O
especially	O
by	O
his	O
lifelong	O
championing	O
the	O
idea	O
of	O
unified	O
theories	O
as	O
the	O
only	O
way	O
to	O
truly	O
uncover	O
the	O
underpinnings	O
of	O
cognition	O
.	O
</s>
<s>
Like	O
other	O
influential	O
cognitive	B-Architecture
architectures	I-Architecture
(	O
including	O
Soar	B-Architecture
,	O
CLARION	B-Architecture
,	O
and	O
EPIC	O
)	O
,	O
the	O
ACT-R	B-Language
theory	O
has	O
a	O
computational	O
implementation	O
as	O
an	O
interpreter	O
of	O
a	O
special	O
coding	O
language	O
.	O
</s>
<s>
The	O
interpreter	O
itself	O
is	O
written	O
in	O
Common	B-Language
Lisp	I-Language
,	O
and	O
might	O
be	O
loaded	O
into	O
any	O
of	O
the	O
Common	B-Language
Lisp	I-Language
language	I-Language
distributions	O
.	O
</s>
<s>
This	O
means	O
that	O
any	O
researcher	O
may	O
download	O
the	O
ACT-R	B-Language
code	O
from	O
the	O
ACT-R	B-Language
website	O
,	O
load	O
it	O
into	O
a	O
Common	B-Language
Lisp	I-Language
distribution	O
,	O
and	O
gain	O
full	O
access	O
to	O
the	O
theory	O
in	O
the	O
form	O
of	O
the	O
ACT-R	B-Language
interpreter	O
.	O
</s>
<s>
Also	O
,	O
this	O
enables	O
researchers	O
to	O
specify	O
models	O
of	O
human	O
cognition	O
in	O
the	O
form	O
of	O
a	O
script	O
in	O
the	O
ACT-R	B-Language
language	O
.	O
</s>
<s>
These	O
assumptions	O
are	O
based	O
on	O
numerous	O
facts	O
derived	O
from	O
experiments	O
in	O
cognitive	O
psychology	O
and	O
brain	B-Algorithm
imaging	I-Algorithm
.	O
</s>
<s>
Like	O
a	O
programming	O
language	O
,	O
ACT-R	B-Language
is	O
a	O
framework	O
:	O
for	O
different	O
tasks	O
(	O
e.g.	O
,	O
Tower	O
of	O
Hanoi	O
,	O
memory	O
for	O
text	O
or	O
for	O
list	O
of	O
words	O
,	O
language	O
comprehension	O
,	O
communication	O
,	O
aircraft	O
controlling	O
)	O
,	O
researchers	O
create	O
"	O
models	O
"	O
(	O
i.e.	O
,	O
programs	O
)	O
in	O
ACT-R	B-Language
.	O
</s>
<s>
These	O
models	O
reflect	O
the	O
modelers	O
 '	O
assumptions	O
about	O
the	O
task	O
within	O
the	O
ACT-R	B-Language
view	O
of	O
cognition	O
.	O
</s>
<s>
In	O
recent	O
years	O
,	O
ACT-R	B-Language
has	O
also	O
been	O
extended	O
to	O
make	O
quantitative	O
predictions	O
of	O
patterns	O
of	O
activation	O
in	O
the	O
brain	O
,	O
as	O
detected	O
in	O
experiments	O
with	O
fMRI	B-Algorithm
.	O
</s>
<s>
In	O
particular	O
,	O
ACT-R	B-Language
has	O
been	O
augmented	O
to	O
predict	O
the	O
shape	O
and	O
time-course	O
of	O
the	O
BOLD	B-Algorithm
response	O
of	O
several	O
brain	O
areas	O
,	O
including	O
the	O
hand	O
and	O
mouth	O
areas	O
in	O
the	O
motor	O
cortex	O
,	O
the	O
left	O
prefrontal	O
cortex	O
,	O
the	O
anterior	O
cingulate	O
cortex	O
,	O
and	O
the	O
basal	O
ganglia	O
.	O
</s>
<s>
ACT-R	B-Language
'	O
s	O
most	O
important	O
assumption	O
is	O
that	O
human	O
knowledge	O
can	O
be	O
divided	O
into	O
two	O
irreducible	O
kinds	O
of	O
representations	O
:	O
declarative	O
and	O
procedural	O
.	O
</s>
<s>
Within	O
the	O
ACT-R	B-Language
code	O
,	O
declarative	O
knowledge	O
is	O
represented	O
in	O
the	O
form	O
of	O
chunks	O
,	O
i.e.	O
</s>
<s>
The	O
most	O
well-developed	O
perceptual-motor	O
modules	O
in	O
ACT-R	B-Language
are	O
the	O
visual	O
and	O
the	O
manual	O
modules	O
.	O
</s>
<s>
There	O
are	O
two	O
kinds	O
of	O
memory	O
modules	O
in	O
ACT-R	B-Language
:	O
</s>
<s>
The	O
contents	O
of	O
the	O
buffers	O
at	O
a	O
given	O
moment	O
in	O
time	O
represent	O
the	O
state	O
of	O
ACT-R	B-Language
at	O
that	O
moment	O
.	O
</s>
<s>
The	O
term	O
"	O
production	O
"	O
reflects	O
the	O
actual	O
implementation	O
of	O
ACT-R	B-Language
as	O
a	O
production	B-Application
system	I-Application
,	O
but	O
,	O
in	O
fact	O
,	O
a	O
production	O
is	O
mainly	O
a	O
formal	O
notation	O
to	O
specify	O
the	O
information	O
flow	O
from	O
cortical	O
areas	O
(	O
i.e.	O
</s>
<s>
ACT-R	B-Language
clearly	O
belongs	O
to	O
the	O
"	O
symbolic	O
"	O
field	O
and	O
is	O
classified	O
as	O
such	O
in	O
standard	O
textbooks	O
and	O
collections	O
.	O
</s>
<s>
Members	O
of	O
the	O
ACT-R	B-Language
community	O
,	O
including	O
its	O
developers	O
,	O
prefer	O
to	O
think	O
of	O
ACT-R	B-Language
as	O
a	O
general	O
framework	O
that	O
specifies	O
how	O
the	O
brain	O
is	O
organized	O
,	O
and	O
how	O
its	O
organization	O
gives	O
birth	O
to	O
what	O
is	O
perceived	O
(	O
and	O
,	O
in	O
cognitive	O
psychology	O
,	O
investigated	O
)	O
as	O
mind	O
,	O
going	O
beyond	O
the	O
traditional	O
symbolic/connectionist	O
debate	O
.	O
</s>
<s>
None	O
of	O
this	O
,	O
naturally	O
,	O
argues	O
against	O
the	O
classification	O
of	O
ACT-R	B-Language
as	O
symbolic	O
system	O
,	O
because	O
all	O
symbolic	O
approaches	O
to	O
cognition	O
aim	O
to	O
describe	O
the	O
mind	O
,	O
as	O
a	O
product	O
of	O
brain	O
function	O
,	O
using	O
a	O
certain	O
class	O
of	O
entities	O
and	O
systems	O
to	O
achieve	O
that	O
goal	O
.	O
</s>
<s>
A	O
common	O
misunderstanding	O
suggests	O
that	O
ACT-R	B-Language
may	O
not	O
be	O
a	O
symbolic	O
system	O
because	O
it	O
attempts	O
to	O
characterize	O
brain	O
function	O
.	O
</s>
<s>
Further	O
misunderstandings	O
arise	O
because	O
of	O
the	O
associative	O
character	O
of	O
certain	O
ACT-R	B-Language
properties	O
,	O
such	O
as	O
chunks	O
spreading	O
activation	O
to	O
each	O
other	O
,	O
or	O
chunks	O
and	O
productions	O
carrying	O
quantitative	O
properties	O
relevant	O
to	O
their	O
selection	O
.	O
</s>
<s>
The	O
importance	O
of	O
distinguishing	O
between	O
the	O
theory	O
itself	O
and	O
its	O
implementation	O
is	O
usually	O
highlighted	O
by	O
ACT-R	B-Language
developers	O
.	O
</s>
<s>
Finally	O
,	O
while	O
Anderson	O
's	O
laboratory	O
at	O
CMU	O
maintains	O
and	O
releases	O
the	O
official	O
ACT-R	B-Language
code	O
,	O
other	O
alternative	O
implementations	O
of	O
the	O
theory	O
have	O
been	O
made	O
available	O
.	O
</s>
<s>
These	O
alternative	O
implementations	O
include	O
jACT-R	O
(	O
written	O
in	O
Java	B-Language
by	O
Anthony	O
M	O
.	O
Harrison	O
at	O
the	O
Naval	O
Research	O
Laboratory	O
)	O
and	O
Python	B-Language
ACT-R	B-Language
(	O
written	O
in	O
Python	B-Language
by	O
Terrence	O
C	O
.	O
Stewart	O
and	O
Robert	O
L	O
.	O
West	O
at	O
Carleton	O
University	O
,	O
Canada	O
)	O
.	O
</s>
<s>
Because	O
of	O
these	O
implementational	O
degrees	O
of	O
freedom	O
,	O
the	O
ACT-R	B-Language
community	O
usually	O
refers	O
to	O
the	O
"	O
official	O
"	O
,	O
Lisp-based	O
,	O
version	O
of	O
the	O
theory	O
,	O
when	O
adopted	O
in	O
its	O
original	O
form	O
and	O
left	O
unmodified	O
,	O
as	O
"	O
Vanilla	O
ACT-R	B-Language
"	O
.	O
</s>
<s>
Over	O
the	O
years	O
,	O
ACT-R	B-Language
models	O
have	O
been	O
used	O
in	O
more	O
than	O
700	O
different	O
scientific	O
publications	O
,	O
and	O
have	O
been	O
cited	O
in	O
many	O
more	O
.	O
</s>
<s>
The	O
ACT-R	B-Language
declarative	O
memory	O
system	O
has	O
been	O
used	O
to	O
model	O
human	O
memory	O
since	O
its	O
inception	O
.	O
</s>
<s>
ACT-R	B-Language
has	O
been	O
used	O
to	O
model	O
attentive	O
and	O
control	O
processes	O
in	O
a	O
number	O
of	O
cognitive	O
paradigms	O
.	O
</s>
<s>
A	O
number	O
of	O
researchers	O
have	O
been	O
using	O
ACT-R	B-Language
to	O
model	O
several	O
aspects	O
of	O
natural	O
language	O
understanding	O
and	O
production	O
.	O
</s>
<s>
ACT-R	B-Language
has	O
been	O
used	O
to	O
capture	O
how	O
humans	O
solve	O
complex	O
problems	O
like	O
the	O
Tower	O
of	O
Hanoi	O
,	O
Altmann	O
,	O
E	O
.	O
M	O
.	O
&	O
Trafton	O
,	O
J	O
.	O
G	O
.	O
(	O
2002	O
)	O
.	O
</s>
<s>
or	O
how	O
people	O
solve	O
algebraic	O
equations.Anderson	O
,	O
J	O
.	O
R	O
.	O
(	O
2005	O
)	O
Human	O
symbol	O
manipulation	O
within	O
an	O
integrated	O
cognitive	B-Architecture
architecture	I-Architecture
.	O
</s>
<s>
With	O
the	O
integration	O
of	O
perceptual-motor	O
capabilities	O
,	O
ACT-R	B-Language
has	O
become	O
increasingly	O
popular	O
as	O
a	O
modeling	O
tool	O
in	O
human	O
factors	O
and	O
human-computer	O
interaction	O
.	O
</s>
<s>
Modeling	O
driver	O
behavior	O
in	O
a	O
cognitive	B-Architecture
architecture	I-Architecture
.	O
</s>
<s>
ACT-R/PM	O
and	O
menu	O
selection	O
:	O
Applying	O
a	O
cognitive	B-Architecture
architecture	I-Architecture
to	O
HCI	O
.	O
</s>
<s>
International	O
Journal	O
of	O
Human-Computer	O
Studies	O
,	O
55	O
,	O
41	O
–	O
84.Fleetwood	O
,	O
M	O
.	O
D	O
.	O
&	O
Byrne	O
,	O
M	O
.	O
D	O
.	O
(	O
2002	O
)	O
Modeling	O
icon	O
search	O
in	O
ACT-R/PM	O
.	O
</s>
<s>
More	O
recently	O
,	O
ACT-R	B-Language
has	O
been	O
used	O
to	O
predict	O
patterns	O
of	O
brain	O
activation	O
during	O
imaging	O
experiments.Anderson	O
,	O
J.R.	O
,	O
Fincham	O
,	O
J	O
.	O
M.	O
,	O
Qin	O
,	O
Y.	O
,	O
&	O
Stocco	O
,	O
A	O
.	O
</s>
<s>
Trends	O
in	O
Cognitive	O
Sciences	O
,	O
12(4 )	O
,	O
136	O
–	O
143	O
In	O
this	O
field	O
,	O
ACT-R	B-Language
models	O
have	O
been	O
successfully	O
used	O
to	O
predict	O
prefrontal	O
and	O
parietal	O
activity	O
in	O
memory	O
retrieval	O
,	O
Sohn	O
,	O
M.-H.	O
,	O
Goode	O
,	O
A.	O
,	O
Stenger	O
,	O
V	O
.	O
A	O
,	O
Carter	O
,	O
C	O
.	O
S.	O
,	O
&	O
Anderson	O
,	O
J	O
.	O
R	O
.	O
(	O
2003	O
)	O
.	O
</s>
<s>
Predicting	O
the	O
practice	O
effects	O
on	O
the	O
blood	O
oxygenation	O
level-dependent	O
(	O
BOLD	B-Algorithm
)	O
function	O
of	O
fMRI	B-Algorithm
in	O
a	O
symbolic	O
manipulation	O
task	O
.	O
</s>
<s>
ACT-R	B-Language
has	O
been	O
often	O
adopted	O
as	O
the	O
foundation	O
for	O
cognitive	O
tutors.Lewis	O
,	O
M	O
.	O
W.	O
,	O
Milson	O
,	O
R.	O
,	O
&	O
Anderson	O
,	O
J	O
.	O
R	O
.	O
(	O
1987	O
)	O
.	O
</s>
<s>
What	O
role	O
do	O
cognitive	B-Architecture
architectures	I-Architecture
play	O
in	O
intelligent	O
tutoring	O
systems	O
?	O
</s>
<s>
These	O
systems	O
use	O
an	O
internal	O
ACT-R	B-Language
model	O
to	O
mimic	O
the	O
behavior	O
of	O
a	O
student	O
and	O
personalize	O
his/her	O
instructions	O
and	O
curriculum	O
,	O
trying	O
to	O
"	O
guess	O
"	O
the	O
difficulties	O
that	O
students	O
may	O
have	O
and	O
provide	O
focused	O
help	O
.	O
</s>
<s>
Such	O
"	O
Cognitive	B-Application
Tutors	I-Application
"	O
are	O
being	O
used	O
as	O
a	O
platform	O
for	O
research	O
on	O
learning	O
and	O
cognitive	O
modeling	O
as	O
part	O
of	O
the	O
Pittsburgh	O
Science	O
of	O
Learning	O
Center	O
.	O
</s>
<s>
Some	O
of	O
the	O
most	O
successful	O
applications	O
,	O
like	O
the	O
Cognitive	B-Application
Tutor	I-Application
for	O
Mathematics	O
,	O
are	O
used	O
in	O
thousands	O
of	O
schools	O
across	O
the	O
United	O
States	O
.	O
</s>
<s>
ACT-R	B-Language
is	O
the	O
ultimate	O
successor	O
of	O
a	O
series	O
of	O
increasingly	O
precise	O
models	O
of	O
human	O
cognition	O
developed	O
by	O
John	O
R	O
.	O
Anderson	O
.	O
</s>
<s>
To	O
highlight	O
the	O
importance	O
of	O
the	O
new	O
approach	O
in	O
the	O
shaping	O
of	O
the	O
architecture	O
,	O
its	O
name	O
was	O
modified	O
to	O
ACT-R	B-Language
,	O
with	O
the	O
"	O
R	O
"	O
standing	O
for	O
"	O
Rational	O
"	O
Anderson	O
,	O
J	O
.	O
R	O
.	O
(	O
1993	O
)	O
.	O
</s>
<s>
Their	O
joint	O
work	O
culminated	O
in	O
the	O
release	O
of	O
ACT-R	B-Language
4.0.Anderson	O
,	O
J	O
.	O
R.	O
,	O
&	O
Lebiere	O
,	O
C	O
.	O
(	O
1998	O
)	O
.	O
</s>
<s>
After	O
the	O
release	O
of	O
ACT-R	B-Language
4.0	O
,	O
John	O
Anderson	O
became	O
more	O
and	O
more	O
interested	O
in	O
the	O
underlying	O
neural	O
plausibility	O
of	O
his	O
life-time	O
theory	O
,	O
and	O
began	O
to	O
use	O
brain	B-Algorithm
imaging	I-Algorithm
techniques	O
pursuing	O
his	O
own	O
goal	O
of	O
understanding	O
the	O
computational	O
underpinnings	O
of	O
human	O
mind	O
.	O
</s>
<s>
ACT-R	B-Language
5.0	O
introduced	O
the	O
concept	O
of	O
modules	O
,	O
specialized	O
sets	O
of	O
procedural	O
and	O
declarative	O
representations	O
that	O
could	O
be	O
mapped	O
to	O
known	O
brain	O
systems.Anderson	O
,	O
J	O
.	O
R.	O
,	O
et	O
al	O
.	O
</s>
<s>
A	O
new	O
version	O
of	O
the	O
code	O
,	O
completely	O
rewritten	O
,	O
was	O
presented	O
in	O
2005	O
as	O
ACT-R	B-Language
6.0	O
.	O
</s>
<s>
It	O
also	O
included	O
significant	O
improvements	O
in	O
the	O
ACT-R	B-Language
coding	O
language	O
.	O
</s>
<s>
This	O
included	O
a	O
new	O
mechanism	O
in	O
ACT-R	B-Language
production	O
specification	O
called	O
dynamic	O
pattern	O
matching	O
.	O
</s>
<s>
A	O
description	O
and	O
motivation	O
for	O
the	O
ACT-R	B-Language
6.0	O
is	O
given	O
in	O
Anderson	O
(	O
2007	O
)	O
.Anderson	O
,	O
J	O
.	O
R	O
.	O
(	O
2007	O
)	O
.	O
</s>
<s>
At	O
the	O
2015	O
workshop	O
,	O
it	O
was	O
argued	O
that	O
software	O
changes	O
required	O
an	O
increment	O
in	O
the	O
model	O
numbering	O
to	O
ACT-R	B-Language
7.0	O
.	O
</s>
<s>
The	O
ACT-R	B-Language
software	O
has	O
also	O
been	O
subsequently	O
updated	O
to	O
include	O
a	O
remote	O
interface	O
based	O
on	O
JSON	O
RPC	O
1.0	O
.	O
</s>
<s>
That	O
interface	O
was	O
added	O
to	O
make	O
it	O
easier	O
to	O
build	O
tasks	O
for	O
models	O
and	O
work	O
with	O
ACT-R	B-Language
from	O
languages	O
other	O
than	O
Lisp	B-Language
,	O
and	O
the	O
tutorial	O
included	O
with	O
the	O
software	O
has	O
been	O
updated	O
to	O
provide	O
Python	B-Language
implementations	O
for	O
all	O
of	O
the	O
example	O
tasks	O
performed	O
by	O
the	O
tutorial	O
models	O
.	O
</s>
<s>
In	O
1995	O
,	O
Carnegie	O
Mellon	O
University	O
began	O
hosting	O
their	O
Annual	O
ACT-R	B-Language
Workshop	O
and	O
Summer	O
School	O
.	O
</s>
<s>
Their	O
ACT-R	B-Language
Workshop	O
is	O
currently	O
hosted	O
at	O
the	O
annual	O
MathPsych/ICCM	O
Conference	O
,	O
and	O
their	O
Summer	O
School	O
is	O
hosted	O
on-campus	O
with	O
a	O
virtual	O
attendance	O
option	O
at	O
Carnegie	O
Mellon	O
University	O
.	O
</s>
<s>
The	O
long	O
development	O
of	O
the	O
ACT-R	B-Language
theory	O
gave	O
birth	O
to	O
a	O
certain	O
number	O
of	O
parallel	O
and	O
related	O
projects	O
.	O
</s>
<s>
The	O
most	O
important	O
ones	O
are	O
the	O
PUPS	O
production	B-Application
system	I-Application
,	O
an	O
initial	O
implementation	O
of	O
Anderson	O
's	O
theory	O
,	O
later	O
abandoned	O
;	O
and	O
ACT-RN	O
,	O
a	O
neural	O
network	O
implementation	O
of	O
the	O
theory	O
developed	O
by	O
Christian	O
Lebiere	O
.	O
</s>
<s>
Lynne	O
M	O
.	O
Reder	O
,	O
also	O
at	O
Carnegie	O
Mellon	O
University	O
,	O
developed	O
SAC	B-Architecture
in	O
the	O
early	O
1990s	O
,	O
a	O
model	O
of	O
conceptual	O
and	O
perceptual	O
aspects	O
of	O
memory	O
that	O
shares	O
many	O
features	O
with	O
the	O
ACT-R	B-Language
core	O
declarative	O
system	O
,	O
although	O
differing	O
in	O
some	O
assumptions	O
.	O
</s>
<s>
For	O
his	O
dissertation	O
at	O
Carnegie	O
Mellon	O
University	O
,	O
Christopher	O
L	O
.	O
Dancy	O
developed	O
,	O
and	O
successfully	O
defended	O
in	O
2014	O
,	O
ACT-R/Phi	O
,	O
Dancy	O
,	O
C	O
.	O
L.	O
,	O
Ritter	O
,	O
F	O
.	O
E.	O
,	O
&	O
Berry	O
,	O
K	O
.	O
(	O
2012	O
)	O
.	O
</s>
<s>
Towards	O
adding	O
a	O
physiological	O
substrate	O
to	O
ACT-R	B-Language
.	O
</s>
<s>
an	O
implementation	O
of	O
ACT-R	B-Language
with	O
added	O
physiological	O
modules	O
which	O
enable	O
ACT-R	B-Language
to	O
interface	O
with	O
human	O
physiological	O
processes	O
.	O
</s>
