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Monkey CANTAB
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Primate version of CANTAB
– the Cambridge Neuropsychological Test Automated Battery
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Computerized Cognitive
Assessment for non-human primates
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Comprises tests from the
human batteries, adapted for use with non-human primates
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Facilitates a direct
comparison with human data
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Facilitates comparisons
with other species, e.g. rodents
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Proved results with both
Rhesus monkeys and marmosets
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Now available – New
Windows version of the software, allowing even more flexibility to
change the tests to your own design
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Monkey CANTAB is the
primate version of CANTAB. Alterations from the human tests have been
restricted to the absolute minimum consistent with the ability of the
animals to learn the tasks. This facilitates a direct comparison with
results from the human batteries. The excellent sensitivity of the
tests and the direct comparison with human results makes Monkey CANTAB
ideal for:
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the characterization of
the functional organization of the brain
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the development of new
and improved animal models of brain disorders
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the early identification
of progressive disorders, whether endogenous or as a result of
environment
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| The Tests:
Monkey CANTAB comprises a battery of tests performed via a touch
screen. Batteries can be configured for either the Rhesus monkey
(pellet reward) or for Marmoset (liquid reward).
The battery is comprised of the following tests:
- Reinforcement Familiarization
- Training Program
- Intra/Extra-Dimensional Set-Shift
and Visual Discrimination (ID/ED)
- Delayed Match / Non-Match to Sample
- Spatial Working Memory
- Five-Choice Serial Reaction-Time
Task
- Paired Associates Learning
- Schedules – FR, FI, VR, VI,
Progressive Ratio
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| The
Apparatus: Robust
aluminum testing station incorporating a LCD
monitor and toughened splash-proof IR touch-screen System allows
for testing in the home cage. |
| Remote control
and monitoring: A 10m cable connects the
test unit to the multimedia control unit. Call-up window allows you to
see what the Monkey does and also shows where the monkey is pointing.
System can also run Whisker Multimedia software, which allows you
to program your own schedules. |
Picture shows marmoset set-up with
peristaltic pump and central licker. (Also available as Rhesus monkey
set-up with 190mg pellet dispenser and trough.) |
| Monkey
CANTAB - Background Monkey
CANTAB was developed by a group including Drs T.W. Robbins and A.C.
Roberts at the University of Cambridge, Department of Experimental
Psychology, from a research program funded by the Wellcome Trust to
improve the comparative assessment from animals to man. |
| Monkey
CANTAB uses two complementary approaches in order to facilitate
cross-species comparison: |
- Animal tasks that have proven useful
in establishing the neural substrate of certain cognitive functions
have been adapted to make them applicable to humans. These include
Matching to Sample and Spatial Working Memory
- Clinical neuropsychological
paradigms, such as the Wisconsin Card Sort Test for measuring
attentional set-shifting ability, have been rendered more accessible
for monkeys
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| The result is
a battery of tests that can be used to study cognition in both
experimental primates in the laboratory and humans in the clinic. An
important consideration in the development of monkey CANTAB has been
to maximize the likelihood that the same cognitive abilities are used
by both monkeys and man to perform each test. Consequently, complex
tasks are decomposed into their constituent elements and each element
assessed independently of the next in a step-by-step progression
through the test. Guiding a subject through the test in this way
restricts the use of alternative strategies and permits an analysis of
performance in terms of the cognitive components involved. Functional
equivalence is suggested if the pattern of performance of monkey and
man, at each stage of the test, is qualitatively similar and if
comparable impairments are seen following damage to selective brain
structures. This has been demonstrated for the Intra/Extra-Dimensional
Set-Shift (ID/ED), the CANTAB analogue of the Wisconsin Card Sort Test
[see Roberts et al (1996a) and Owen et al (1991)]
Monkey CANTAB – characterization of the functional organization of
the brain - These tests are important in assessing the precise
nature of the cognitive deficits in experimental primates following a
variety of CNS manipulations, including the permanent or reversible
removal of selective neurotransmitter systems and the destruction of
specific brain structures. For example the ID/ED has been used
successfully in marmosets to differentiate the role of the cholinergic
(Roberts et al, 1992) and dopaminergic (Roberts et
al, 1994) innervation of the prefrontal cortex and the
dopaminergic innervation of the caudate nucleus (Roberts et al,
1996b). In addition, this test has been used to characterize the
functional organization within the prefrontal cortex itself (Dias
et al, 1996).
Monkey CANTAB – improved animal models of brain disorders -
Extrapolations of these results into the clinic have proven useful in
characterizing both the neural and neurochemical basis of the
cognitive deficits in Parkinson’s disease (Downes et al, 1989)
and Alzheimer’s disease (Sahakian et al, 1990). Thus, the tests
can be used to develop good animal models of a variety of brain
disorders. Some of these tests have also proven sensitive to the
progressive decline in cognitive abilities associated with the
infection of rhesus monkeys by SIV (Gold et al, 1996) and so
can be used to study new treatments, not only for HIV and AIDS
sufferers, but also for patients with other neurodegenerative
conditions.
The excellent sensitivity of the tests gives them particular
utility in the early identification of progressive disorders, whether
endogenous or brought about as a result of environment. |
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| Monkey CANTAB - tests
in the battery |
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Reinforcement
Familiarization
The aim of this program is
to teach the monkeys that the onset of a tone signals the availability
of reinforcement. This is the standard signal for the availability of
reinforcement across all the cognitive tests.
Features:
Training Program
The aim of this program is
to train the monkey to touch a solid box that is presented anywhere on
the computer touch screen.
Features:
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Up to seven box sizes
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Boxes may be one of seven
colors
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A touch outside the box
restarts the trial
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Reinforcement delivery
optionally contingent upon an independent response (e.g. licking)
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Intra/Extra Dimensional
Set-Shift and Visual Discrimination (ID/ED)
(illustrated above)
This set of visual
discrimination and reversal tests can be used to study a range of
cognitive processes including:
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Simple associative learning, i.e.
learning that a response to a particular stimulus is associated with
reinforcement
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Selective attention, i.e. learning to
attend selectively to a particular dimensional property of the
stimulus
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Attentional set-shifting, i.e. learning
to shift attention from one dimensional property of another stimulus
The two types of test that
make up this program use either ‘simple’ (one-dimensional) or
‘compound’ (two-dimensional) stimuli. The dimensions used are
color-filled shapes and white lines. Simple stimuli are composed of
just one of these dimensions, whereas compound stimuli are composed of
both. The stimuli are the same as those used for the human test.
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Delayed
Matching/Non-Matching to Sample
This program tests the
short-term memory using a non-repeating sequence of arbitrary symbols,
analogous to the use of junk objects in the WGTA. The symbols used are
the same as those used for the human CANTAB Delayed Match to Sample
Test.
A sample stimulus (symbol)
is presented in the centre of the screen. Following an observing
response the stimulus will either vanish (memory trial) or stay on the
screen (simultaneous trial). After a delay, which may be zero, the
sample stimulus reappears around the edge of the screen along with 1
(in the case of a non-matching trial) or 1-3 (in the case of a
matching trial) novel stimuli. For a non-matching trial the subject
must touch the novel stimulus to receive reinforcement, for a matching
trial the subject must touch the sample stimulus.
Spatial Working Memory
This program provides a test of working memory analogous to that
tested in rodents with an 8-arm maze. A number of boxes appear on the
screen with no obvious pattern. The subject must select each box in
turn without revisiting a box once it has been touched. A number of
options are available for training the subjects and for varying the
difficulty of the task.
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Five-choice Serial Reaction Time
This task is analogous to Leonard’s 5-Choice Serial Reaction Time
Task, which is based on the Continuous Performance test of Rosvold and
Mirsky. The subject is presented with a display of five open circles,
whereupon it must make an observing response by pressing a key. The
key must be held for a minimum time, which can be zero (immediate
release). After a delay, a filled circle appears within one of five
open circles. This circle is presented for a specified duration, which
may be unlimited. If the subject touches the filled circle or the
place where it was presented, it is reinforced: incorrect responses
are punished. The accuracy of the response and the reaction time are
recorded.
Paired Associates Learning
This is a conditional learning and memory task in which the location
of trial-unique patterns must be learned and remembered. The test is
progressive. There are six levels of difficulty (stages 1 and 2 are
for training):
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Sample Stage - A single pattern
is presented at one location on the screen and an empty box at
another (subject must touch the pattern and the box as each is
presented). Choice Stage - After a delay, the pattern is presented
in both locations simultaneously. The subject must touch the
location at which the pattern appeared during the sample stage to
receive reinforcement.
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Sample Stage - A single pattern
and two empty boxes are presented in turn on the screen. Choice
Stage - After a delay, the pattern is presented in all three
locations simultaneously. The subject must touch the location at
which the pattern appeared during the sample stage.
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Sample Stage - A single pattern
and three empty boxes are presented in turn. Choice Stage - After a
delay, the pattern is presented in all four locations
simultaneously. The subject must touch the location at which the
pattern appeared during the sample stage.
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Sample Stage – Two Patterns and
two empty boxes are presented in turn. Choice Stage - After a delay,
there is a serial presentation of the patterns used during the
sample stage. In each presentation the pattern appears
simultaneously in all four locations. The subject must touch the
location at which the particular pattern appeared during the sample
stage.
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As for stage 4 with three patterns and
one box.
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As for stage 4 with four patterns.
An alternative method of training may be
used in which the empty boxes are omitted.
Features:
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Novel patterns on every trial
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Each trial repeated until correct
(changing order of presentation)
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Pre-training stage for task
familiarization
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Two alternative training procedures
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Six levels of difficulty – two training
and four test
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Each session can have multiple
(progressive) stages
Schedules – FR, FI, VR, VI, Progressive Ratio
This program provides conventional Operant schedules of responding to
a fixed square at the centre of the screen.
Features:
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FR, FI, VR, VI or Progressive Ratio
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Selectable box size and color
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Optional change of color on response
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Optional breakpoint
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