Conditioned Inhibition
Conditioned inhibition is an internal state that
prevents an organism from making some response,
like salivation.
As an intervening variable, it must be operationally
defined.
To say that that an organism has acquired a
conditioned inhibitory response, two tests must be
passed: (1) retardation test; (2) summation test.
In these examples, there are 2 CSs:
CSB
CSC clicks
Conditioned Inhibition
Retardation Test
Phase 1
Experimental
Group
Control
Group
Inhibitory training
with CSB
No experience
with CSB
Phase 2 (test)
CSB
is paired
with US until
there is a strong
CR.
CSB
is inhibitory if it takes the Experimental
Group more trials to learn a CR than it takes the
Control Group.
In other words, the previous inhibitory training slows
down learning in the Experimental Group.
Conditioned Inhibition
Why Does the Experimental Group Learn More Slowly?
Excitation
+
Tendency
to Salivate
to CSB
0
Inhibition
The Control
Group starts
at 0.
Going from
Trial 1 to
Trial 5, the
level of
excitation
increases.
Conditioned Inhibition
Why Does the Experimental Group Learn More Slowly?
Excitation
+
Tendency
to Salivate
to CSB
0
Inhibition
The
Experimental
Group starts
below 0.
It takes extra
trials to
bring them
up to 0, then
more trials
to raise the
level of
excitation.
Conditioned Inhibition
Summation Test
The logic is as follows: If you combine a positive
value (like +9) with a negative value (like –4), the
sum will be lower than the positive value alone.
The positive value is an “excitatory” CS, a
CS that has been paired with the US.
The negative value is an “inhibitory” CS, a CS that
has been used in some form of inhibitory training.
Excitatory stimulus:
CSC clicks
Inhibitory stimulus:
CSB
Conditioned Inhibition
Summation Test
Phase 1
The Experimental Group receives inhibitory
training with CSB
.
The Control Group receives no training with
CSB
.
Conditioned Inhibition
Summation Test
Phase 2
Both groups receive pairings between CSC
and the US until there is a strong CR.
clicks
Conditioned Inhibition
Summation Test
Phase 3
CSB and CSC are combined and presented
together for a few trials without the US.
If CSB is inhibitory, the CR should be weaker in the
Experimental group than in the Control group.
This is because CSB is neutral (has a value of 0)
for the Control group but has a negative value
for the Experimental group.
Combining a negative CS with a positive CS
produces less excitation than combining a
neutral CS with a positive CS.