Working Memory – Goal Maintenance
Task Name
Description
Cognitive Construct Validity
Probabilistic
Reversal
Learning
Subjects select one stimulus from an
array of concurrently presented stimuli
(preferably 3); typically, more than one
set of discriminanda are presented, in a
randomized order across trials. Each
choice is followed by positive or
negative feedback (correct choice or
incorrect choice). The relationship
between the stimulus presented and
the feedback given can be deterministic
or probabilistic. Subjects must, based
upon feedback alone, learn which cue
in each discriminanda set are
associated with positive feedback and
then maintain optimized performance of
the rule (rule maintenance). Once the
subject meets pre-set performance
criteria, feedback is adjusted without
warning. In other words, the rules are
"reversed" in one or more of the
discriminanda sets. Subjects must
update their behavior based upon the
change in rules. Optimal reversal
performance is often considered to
involve cognitive control over prepotent responding.
Acquisition of a multiple
choice visual discrimination is
believed to reflect implicit
learning processes. Optimal
performance of a visual
discrimination is thought to
reflect rule maintenance.
Reversal of a learned visual
discrimination is thought to
measure cognitive control over
pre-potent responding
(response inhibition).
(Waltz & Gold, 2007)
(Lee, Groman, London, & Jentsch,
2007)
(Frank & Claus, 2006)
MANUSCRIPTS ON THE WEBSITE:
Cools, R., Altamirano, L., & D'Esposito,
M. (2006). Reversal learning in
parkinson's disease depends on
medication status and outcome
valence. Neuropsychologia, 44(10),
1663-1673.
Waltz, J. A., & Gold, J. M. (2007).
Probabilistic reversal learning
Neural Construct
Validity
Interactions between
declarative systems
(hippocampal and
prefrontal) and implicit
systems (striatum) are
predicted across initial
learning of a
discrimination, such
that increasing
activation in the
striatum, as a function
of trials performed,
occurs along with
learning. The
ventrolateral and
ventromedial frontal
cortex are particularly
involved in the
effective inhibition of
responses at reversal.
(Dias, Robbins, &
Roberts, 1996, 1997)
(Fellows & Farah,
2005)
(Fellows & Farah,
2003)
Reliability
As this is a
"learning" task,
test-retest
reliability is
unavailable.
Psychometric
Characteristics
Practice effects are
unknown, but are the
subject of active
investigation. Depending
upon how the test is
conducted, there can be
ceiling effects for
discrimination learning.
The use of multiple
discriminada sets, at least
3 stimuli in each set and
probabilistic feedback can
avoid this.
Animal Model
Stage of Research
Analogous tests
for mice, rats and
monkeys exist.
There is evidence
that this specific task
elicits deficits in
schizophrenia.
(Lee et al., 2007)
(Boulougouris,
Dalley, & Robbins,
2007)
(Chudasama &
Robbins, 2006)
We need to assess
psychometric
characteristics such
as test-retest
reliability, practice
effects, and
ceiling/floor effects
for this task.
We need to study
whether or not
performance on this
task changes in
response to
psychological or
pharmacological
intervention
BUT: (Cools,
Altamirano, &
D'Esposito, 2006;
Cools, Lewis, Clark,
Barker, & Robbins,
2007)
impairments in schizophrenia: further
evidence of orbitofrontal dysfunction.
Schizophrenia Research, 93(1-3), 296303.
Operation
Span/
Symmetry
Span
“In the first published version of the
Operation Span Task, 12 items were
presented, with 3 items each consisting
of two, three, four, and five operation
word pairs, presented in ascending
order. The stimuli consisted of
mathematical operations followed by a
to-be-remembered word, drawn from
the same normed set of common fourto six-letter words as that for Turner
and Engle’s version of the reading span
task. When the operation word string
was presented, the subjects read the
operation aloud and verified whether
the stated solution was correct or
incorrect. They then read aloud and
remembered the word for later recall.
All intermediate calculations were done
silently and without the aid of pencil
and paper. Engle et al. (1992)
developed the version of the operation
span task currently used in our
laboratories. The primary difference
from earlier versions is the
manipulation of presentation order.
Rather than presenting reading span
and operation span items in ascending
order (items with fewer elements first),
which permitted the subjects to
anticipate the number of words that
they would be asked to remember on
any given trial, Engle et al. (1992)
randomized the presentation order,
effectively eliminating reliance on any
strategies that come from knowing the
size of the memory set.2 This
modification has the added benefit of
deconfounding item size and buildup of
proactive interference, since recent
studies have shown that proactive
interference builds from trial to trial in
This task has more
demonstrated construct
validity than all other WM
tasks combined.
This task has been
shown to individually
and at the latent
variable level to be
valid
This task, in
several versions,
has been shown
to be reliable over
repeated
administrations
and also split half.
Good internal
consistency. Good
retest reliability
over up to 3 month
(.7 and above).
(Conway et al.,
2005)
(Klein & Fiss,
1999)
(Unsworth, Heitz,
Schrock, & Engle,
2005)
The task has been used in
studies where it was
administered at least a
dozen times and even late
in the study still correlated
with errors after a period of
sleep deprivation
(Conway et al., 2005)
(Klein & Fiss, 1999)
(Unsworth, Heitz, Schrock,
& Engle, 2005)
NONE
This specific task
needs to be studied
in individuals with
schizophrenia.
Data already exists
on psychometric
characteristics of this
task, such as testretest reliability,
practice effects,
ceiling/floor effects.
We need to study
whether or not
performance on this
task changes in
response to
psychological or
pharmacological
intervention.
WM span tasks (Bunting, in press;
Lustig, May, & Hasher, 2001; May,
Hasher, & Kane, 1999). It also results
in a wider range of scores than does
the traditional ascending approach. A
potential risk of this approach, however,
is that the early presence of difficult
items may discourage some subjects,
particularly those who are less able,
such as children, the elderly, or
patients. (Our advice to researchers
working with such populations is to
stress to the subject that perfect recall
is not expected in these tasks.)”
The above taken from pp. 73-74 of
Conway et al., 2005)
(R W Engle, Kane, & Tuholski, 1999)
(R. W. Engle, Tuholski, Laughlin, &
Conway, 1999)
(Kane et al., 2004)
(Conway et al., 2005)
Symmetry Span: In this task
participants were required to recall
sequences of red squares within a
matrix while performing a symmetryjudgment task. In the symmetryjudgment task participants were shown
an 8 x 8 matrix with some squares filled
in black. Participants decided whether
the design was symmetrical about its
vertical axis. The pattern was
symmetrical half of the time.
Immediately after determining whether
the pattern was symmetrical,
participants were presented with a 4 x 4
matrix with one of the cells filled in red
for 650 ms. At recall, participants
recalled the sequence of red-square
locations in the preceding displays, in
the order they appeared by clicking on
the cells of an empty matrix. There
were three trials of each set-size with
list length ranging from 2-5. The same
scoring procedure as Ospan was used.
The above taken from Unsworth
(2006).
MANUSCRIPTS ON THE WEBSITE:
Conway, A. R., Kane, M. J., Bunting, M.
F., Hambrick, D. Z., Wilhelm, O., &
Engle, R. W. (2005). Working memory
span tasks: A methodological review
and user's guide. Psychon Bull Rev,
12(5), 769-786.
Unsworth, N., Heitz, R. P., Schrock, J.
C., & Engle, R. W. (2005). An
automated version of the operation
span task. Behav Res Methods, 37(3),
498-505.
AX-CPT
In this task, participants are presented
with cue–probe pairs and told to make
a target response to an “X” (probe) but
only when it follows an “A” (cue), and a
nontarget response otherwise. A
correct response to “X” depends upon
maintaining the “goa” or “context”
provided by the cue (“A” or not-“A”).
One change to the standard AX-CPT
was to increase the frequency of target
(“AX”) trials so that they occur with a
high frequency (70%), with the
remaining 30% of trials distributed
across three types of nontarget trials
(“BX”, “AY”, and “BX” where “B” refers
to any non-“A” cue and “Y” refers to any
non-“X” probe). This creates two types
of biases that can be used to probe the
integrity of goal maintenance. The first
bias, or prepotent response, is that
participants expect to make a target
response when they see an “X” probe,
because this is the correct response on
most of the trials (87.5% of trials in
which an X is presented). On “BX”
trials, participants have to use to the
Original model demonstrating
framework for context
processing: (Cohen & ServanSchreiber, 1992)
Formal model of AX task
linking performance to DA
gating: (Braver, Barch, &
Cohen, 1999)
Demonstration of convergence
of context processing
performance, and deficits in
patients, across three tasks:
(Cohen, Barch, Carter, &
Servan-Schreiber, 1999)
Evidence of trait-like
impairment in schizophrenia
patients: (A. W. MacDonald,
3rd et al., 2005)
Evidence of specificity of
impairment and relation to
PFC dysfunction: (Barch,
Sheline, Csernansky, &
Performance on the
AX-CPT improves in
response to
amphetamine
administration in both
individuals with
schizophrenia (Barch
& Carter, 2005) and
healthy controls
(Barch & Braver,
2007).
BX errors had an
alpha of .88 (J. D.
Cohen, D. M.
Barch, C. S.
Carter, & D.
Servan-Schreiber,
1999).
This task can elicit
different deficits in goal
(context) processing
(Barch et al., 2001; Barch,
Carter et al., 2003; Barch
et al., 2004; J.D. Cohen et
al., 1999; Javitt, Shelley,
Silipo, & Lieberman, 2000;
D. Servan-Schreiber, J. D.
Cohen, & S. Steingard,
1996; Stratta, Daneluzzo,
Bustini, Casacchia, &
Rossi, 1998; Stratta,
Daneluzzo, Bustini,
Prosperini, & Rossi, 2000).
Simon Killcross
has argued that he
has a rodent
paradigm that
measures
something similar
(Haddon &
Killcross, 2007).
There is evidence
that this specific task
elicits deficits in
schizophrenia.
We need to assess
psychometric
characteristics such
as test-retest
reliability, practice
effects, and
ceiling/floor effects
for this task.
There is evidence
that performance on
this task can
improve in response
to psychological or
pharmacological
interventions.
context provided by the “B” cue to
inhibit this bias to respond target to an
“X” (which would lead to a false alarm).
Thus, impaired goal representations will
lead to poor performance on “BX” trials,
because the goal (context) provided by
the “B” cue would not be available to
override the tendency to want to
response target to the “X.” The second
bias is that participants expect to make
a target response after they see an “A”
cue, because most of the time an “X”
follows the “A” cue (87.5% of “A” cue
trials). However, on trials in which the
“A” is not followed by an “X”, this
predictive aspect of context actually
creates the tendency to false alarm.
Thus, intact representations of context
will hurt performance on “AY” trials,
because context induces an invalid
expectancy, leading to worse “AY” than
“BX”
performance.
In
contrast,
individuals with impaired context
representations should show worse
“BX” than “AY” performance.
Snyder, 2003)
Link to PFC impairment in
unmedicated patients,
specificity of impairments to
schizophrenia, and further
demonstrating link to
disorganization symptoms of
schizophrenia: (A. MacDonald
et al., 2005)
(Cohen & Servan-Schreiber,
1992)
(Braver et al., 1999)
(Cohen et al., 1999)
(A. W. MacDonald, 3rd et al.,
2005)
(Barch, Carter, & Cohen,
2003)
(Barch, Sheline et al., 2003)
(A. MacDonald et al., 2005)
(A. W. MacDonald et al.,
2003)
REVIEW WITH THE DPX
Dot Pattern
Expectancy
Task
Dot Pattern Expectancy Task. This task
is a variant of expectancy manipulation
of the AX-CPT (Servan-Schreiber,
Cohen, & Steingard, 1996). It uses dot
pattern stimuli instead of letters to 1)
increase difficulty of maintaining
information and 2) manipulate the
interference from invalid stimuli more
parametrically than was possible with
letters. These manipulations decrease
ceiling effects, increase the likelihood of
observing a differential deficit, and may
increase reliability.
(MacDonald et al., 2005)
MANUSCRIPTS ON THE WEBSITE:
DPX is formally equivalent to
the expectancy AX task, upon
which it is built. The conditions
of interest have been shown to
be statistically equivalent to
the AX, which has an
extensive history in the clinical
cognitive neuroscience
literature: Original model
demonstrating framework for
context processing: (Cohen &
Servan-Schreiber, 1992)
Formal model of AX task
linking performance to DA
gating: (Braver, Barch, &
Cohen, 1999)
This kind of goal
maintenance, known
as context processing,
has been shown to be
associated with
activity in DLPFC
(predominantly BA 9).
(Barch et al., 1997)
(A. W. MacDonald,
3rd, Cohen, Stenger,
& Carter, 2000)
Preliminary data
from unpublished
studies.
Furthermore,
these data have
also been
evaluated to
determine whether
a shorter version
would maintain
reliability:
Among 210
undergraduates,
coefficient alpha
for AX trials was
.91 across 120
trials, and .85 for
The task has been found
to be capable to
demonstrating differential
deficits in three studies,
including the original
study. These studies also
indicate that errors rates
on the AY condition are
10-20% in controls, and on
the BX condition are 613%.
None known.
Current work
includes a monkey
homologue using
visual locations to
define valid cues
and probes with
an otherwise
formallyequivalent
expectancy
manipulation.
There is evidence
that this specific task
elicits deficits in
schizophrenia.
Data already exists
on psychometric
characteristics of this
task, such as testretest reliability,
practice effects,
ceiling/floor effects.
We need to study
whether or not
performance on this
task changes in
Cohen, J. D., Barch, D. M., Carter, C.,
& Servan-Schreiber, D. (1999).
Context-processing deficits in
schizophrenia: Converging evidence
from three theoretically motivated
cognitive tasks. Journal of Abnormal
Psychology, 108, 120-133.
MacDonald, A. W., 3rd, Goghari, V. M.,
Hicks, B. M., Flory, J. D., Carter, C. S.,
& Manuck, S. B. (2005). A convergentdivergent approach to context
processing, general intellectual
functioning, and the genetic liability to
schizophrenia. Neuropsychology, 19(6),
814-821.
Demonstration of convergence
of context processing
performance, and deficits in
patients, across three tasks:
(Cohen, Barch, Carter, &
Servan-Schreiber, 1999)
Demonstrating statistical
equivalence of DPX to
expectancy AX in general
population sample (n=500),
relationship to working
memory and IQ, and
impairments on DPX
associated with unexpressed
genetic liability:(A. W.
MacDonald, 3rd et al., 2005)
In addition: Evidence of traitlike impairment in
schizophrenia patients: (A. W.
MacDonald, 3rd et al., 2005)
Evidence of specificity of
impairment and relation to
PFC dysfunction: (Barch,
Sheline, Csernansky, &
Snyder, 2003)
Demonstration of relatively
greater sensitivity of DPX
relative to NBack and AX task
to polymorphisms in COMT
gene: (A. W. MacDonald, 3rd,
Carter, Flory, Ferrell, &
Manuck, 2007)
Link to PFC impairment in
unmedicated patients,
specificity of impairments to
schizophrenia, and further
demonstrating link to
disorganization symptoms of
schizophrenia: (A. MacDonald
the first 46 trials.
Alpha for BX trials
was likewise .76
across all 16 trials,
whereas it was .71
for the first 8 trials.
AY trials were not
as internally
consistent, with
alpha=.46 for all
trials and .20 for
the first 8 trials. In
terms of retest
reliability, 70
mixed healthy and
psychiatric
patients 6-week
retest reliability
(single measure
absolute ICC’s)
was .78 and .56
for AX and BX
trials, respectively.
Among the 10
schizophrenia
patients in this
sample, retest
reliability was .94
and .79 for AX and
BX trials,
respectively. For
AY trials, retest
reliability was
lower, ICC = .57.
response to
psychological or
pharmacological
intervention.
et al., 2005)
Evidence that context
processing is related to
genetic liability to
schizophrenia: (A. W.
MacDonald, Pogue-Geile,
Johnson, & Carter, 2003)
(Cohen & Servan-Schreiber,
1992)
(Braver et al., 1999)
(Cohen et al., 1999)
(A. W. MacDonald, 3rd et al.,
2005)
(Barch, Carter, & Cohen,
2003)
(Barch, Sheline et al., 2003)
(A. MacDonald et al., 2005)
(A. W. MacDonald et al.,
2003)
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