Conditional learning

1
C82LEA Biology of learning and memory
Conditional learning
Charlotte Bonardi
2
(No Transcript)
3
A red light means....
4
A red light means....
5
(No Transcript)
6
JAM!!
7
JAM!!
8
(No Transcript)
9
newspaper
10
newspaper
journal
11
periódico
shinbun
12
Conditional control of associations
The same stimulus can be associated with two
different outcomes. Which association is
retrieved is conditional on the context in which
the stimulus is presented. This allows the
associations to represent knowledge in a
versatile way. The context appears to control
access to the CS--gtUS association.
spanish
periódico
newspaper
english
13
Conditional control of associations
Standard associative theories can't explain
this -- the association forms and thats it.
... maybe associative theory cannot explain
all animal learning? Questions Is
conditional control really independent of
associative learning? If so, how does it work?
14
Conditional learning in animals
Feature-positive discrimination lighttone
---gt food tone --gt
nothing
15
Conditional learning in animals
Feature-positive discrimination lighttone
---gt food tone --gt
nothing Associative theory predicts that the
light is strongly associated with food ... and
that the tone is not On reinforced trials the
light and the tone both acquire some strength
on nonreinforced trials the tone loses it again.
As there is only limited associative strength
available, eventually the light gets it all, and
the tone is left with nothing.
16
Conditional learning in animals
Feature-positive discrimination lighttone
---gt food tone --gt
nothing Associative theory predicts that the
light is strongly associated with food ... and
that the tone is not On reinforced trials the
light and the tone both acquire some strength
on nonreinforced trials the tone loses it again.
As there is only limited associative strength
available, eventually the light gets it all, and
the tone is left with nothing. But how do you
know this is what is happening?
17

• Ross and Holland 1981
• Used the fact that auditory and visual stimuli
  elicit different behaviours in the rat
• auditory "headjerk"
  visual "rearing"
• They examined responding in two groups of
  animals
• 1 light tone --gt food tone --gt
  nothing
• 2 light tone --gt food light --gt
  nothing

18

• Ross and Holland 1981
• Used the fact that auditory and visual stimuli
  elicit different behaviours in the rat
• auditory "headjerk"
  visual "rearing"
• They examined responding in two groups of
  animals
• 1 light tone --gt food tone --gt
  nothing
• 2 light tone--gt food light --gt
  nothing

19
(No Transcript)
20

• The rats learned exactly according to the
  Rescorla Wagner model
• light tone --gt food tone --gt nothing
• 
  rearing to light
• light tone --gt food light --gt
  nothing
• headjerking to tone
• But if you don't have the light and the tone
  simultaneous something else happens...

21
Ross and Holland, 1981
simultaneous
22
Ross and Holland, 1981
simultaneous
23
Ross and Holland, 1981
simultaneous
serial
24
Ross and Holland, 1981
simultaneous
rear
serial
25
Ross and Holland, 1981
simultaneous
rear
serial
headjerk
headjerk
In serial case hard for light to associate with
food so tone can
26
headjerk
headjerk
Headjerk response suggests responding is based on
the tone?foood association.... and it seems to
be stronger after the light!
tone
food
so is the light acting as a switch???
light
27
headjerk
headjerk
...or is it just associated with food too??
tone
food
Although the light is not closely followed by
food, it is always followed by food delivery
Maybe the rats headjerk more to the tone when
the light has been on because they are already
expecting food, and this boosts the headjerk CR
elicited by the tone.
light
28
grub up!
29
grub up!
30
tone
food
light
We can test this by extinguishing the
light--gtfood association. Will the rats headjerk
to the tone when it is followed by the light? If
they do, we cannot explain the results in terms
of associative learning.
31
Holland, 1989
Two groups of animals Group FP
Light?tone?food, tone? no food Group PP
Light?tone?food, tone? no food...
32
Holland, 1989
Two groups of animals Group FP
Light?tone?food, tone? no food Group PP
Light?tone?food, tone? no food, light? no food
33
Holland, 1989
Two groups of animals Group FP
Light?tone?food, tone? no food Group PP
Light?tone?food, tone? no food, light? no
food If the light--gtfood association is
responsible for discrimination in Group FP, then
Group PP should not show any discrimination. This
type of discrimination is called a positive
patterning (PP) discrimination.
34
(No Transcript)
35
(No Transcript)
36
The light is still controlling responding to the
tone, despite the fact that its not associated
with anything. In these cases standard
associative theory cannot explain how the light
is controlling responding. The light may be
called a conditional cue, a modulator, or an
occasion setter. Can get negative occasion
setting too turn OFF an association
37
SIM light tone ? nothing tone ?
shock noise? shock SER light?tone ?
nothing tone ? shock noise? shock A
normal Pavlovian inhibitor will suppress
responding to the noise a summation test will
this also happen in the serial case?

Holland Lamarre, 1984
38
tone
shock
so is the light acting as a negative switch???
light
tone
food
or is the light just a Pavlovian inhibitor?
light
if you can explain the discrimination in terms of
regular classically conditioned associations,
associative theory can explain it dont need
any other theory but if associative theory cant
explain result, need something else -- then light
is an occasion setter
39
suppression ratio
40
Rescorlas modulation theory (Rescorla, 1985)
tone
food
light
Whenever a CS is presented, it must activate the
US representation to get a conditioned response.
If the light is a positive occasion setter, it
lowers its activation threshold -- making it
easier for the CS to activate.
41
Hollands and-gate theory (1983)
tone
food
light
The light acts as an and-gate, allowing
activation to flow from the CS to the US, and so
elicit a conditioned response.
42
These theories make different predictions about
transfer Suppose you also pair a clicker with
food would you expect the light to elevate
responding to the clicker as well?
click
tone
food
43
click
food
tone
Rescorlas theory says YES. The light is
altering the activation threshold of the food,
and will boost responding to any stimulus that
is associated with it.
light
44
click
food
tone
Hollands theory says NO The light is acting
as an and-gate for the tone--gtfood
association -- not the click--gtfood association
light
45

• Hundreds of experiments later...
• Occasion setters do sometimes transfer their
  effects to other CSs paired with the same US
• (ii) But this transfer effect is seldom as big as
  with the original CS
• Many people have done this experiment (e.g.,
  Holland, 1986 Rescorla,
• 1985). Here is one example, using rats

46
TRAIN light.....tone--gtfood
tone--gt no food
click--gtfood
47
light.....tone--gtfood tone--gt
no food click--gtfood
TRAIN
TEST light.....tone?
tone? light.....click? click?
48
(No Transcript)
49
Holland might say... the animals could
confuse (generalise between) the two CSs (the
tone and the click). This might give a false and
weak) transfer effect
click
light
food
tone
food
light
50
Rescorla might say... animals are upset by
experiencing novel CS combinations (such as the
click and the light) -- this could disrupt
responding, and transfer to a different CS.
click
light
food
food
tone
light
51
So get some transfer to the click
(supporting Rescorla) but less effect than with
the tone (supporting Holland) results are not
conclusive...
52
a complication! (iii) Transfer is better if the
transfer CS has its own occasion setter
click
tone
food
light
53
a complication! (iii) Transfer is better if the
transfer CS has its own occasion setter
click
dark
tone
food
light
54
light.....tone--gtfood, tone--gt no
food dark....click--gtfood
click--gtno food
55
light.....tone? tone? dark...click? click?
SAME
light.....tone--gtfood, tone--gt no
food dark....click--gtfood
click--gtno food
56
light.....tone? tone? dark...click? click? lig
ht.....click? click? dark...tone? tone?
SAME
light.....tone--gtfood, tone--gt no
food dark....click--gtfood
click--gtno food
DIFFERENT
57
Again, many people have done this experiment
(e.g., Holland, 1986, Rescorla, 1985). This is
one example (it actually used pigeons).
58
Conclusions Everyone (including Rescorla!)
agrees Rescorlas theory is too simple occasion
setters specific to training CS Hollands
theory a possibility -- but why better transfer
to a CS from another conditional
discrimination? So Holland (1989) suggested an
occasion setter will transfer perfectly to a CS
that has its own occasion setter not to a CS
that hasnt. Circular...!!
59
Bouton Nelson (1998) occasion setters form
best when tone can acquire strength more easily
than feature... light ? tone ? food tone ?
nothing but tone always losing strength too..
both excitatory and inhibitory links with US

maybe light inhibits the inhibitory link!
60
Bouton Nelson (1998) problem can get
occasion setting even without tone?nothing trials
light ? tone ? food tone ? nothing

tone
food
maybe light inhibits the inhibitory link!
light
61
Bouton Nelson (1998) problem can get
occasion setting even without tone?nothing trials
light ? tone ? food
tone
food
?
no inhibitory link to inhibit!
light
62
An alternative account ... configural
learning although they are given this....
they actually experience something like this...
tone after light
63
..when the tone and the light are presented
together, the animal experiences a configural
blend of the stimuli that is different from
either This tone/light configure is associated
with food in the normal way -- and that is what
produces discrimination performance.
(and extinction of the light doesnt affect
discrimination its a different
stimulus!)
64
It is difficult to discriminate between the
and-gate and configural accounts of occasion
setting -- but it seems the configural account is
not enough to explain all occasion-setting
effects. Occasion setters can be contexts
(places) smells drug states (state
dependence) maybe even apply to tasks like
Stroop red red green green blue
blue task is occasion setter telling you which
association to use the one linked with the name
of the word, or that linked with the colour
65

General
references Bouton, M.E. (2007). Learning and
Behavior. Sinauer Associates. Domjan, M. The
principles of learning and behaviour. (1998).
Brooks/Cole. Advanced Swartzentruber, D.
(1995). Modulatory mechanisms in Pavlovian
conditioning. Animal Learning and Behavior, 23,
123-143. Specific references Bouton, M.E.,
Nelson, J.B. (1998). Mechanisms of
feature-positive and feature-negative
discrimination learning in an appetitive
conditioning paradigm. In P.C. Holland and N.A.
Schmajuk (Eds.) Associative learning and
cognition in animals Occasion setting. APA,
Washington, D.C. Holland, P.C. (1983).
Occasion-setting in Pavlovian feature positive
discriminations. In M.L. Commons, R.J.
Herrnstein, A.R. Wagner (Eds.), Quantitative
analyses of behavior (Vol. 4, pp. 183-206). New
York Ballinger. Holland, P.C. (1986) Transfer
after serial feature-positive occasion setting.
Learning and Motivation, 17, 243-268. Holland,
P.C. (1989b). Feature extinction enhances
transfer of occasion setting. Animal Learning and
Behavior, 17, 269-279. Holland, P.C., Lamarre,
J. (1984). Transfer after serial and
simultaneous feature negative discrimination
training. Learning and Motivation, 15,
219-243. Rescorla, R.A. (1985). Conditioned
inhibition and facilitation. In R.R. Miller
N.E. Spear (Eds.), Information processing in
animals Conditioned Inhibition.(pp. 299-326).
Ross, R.T., Holland, P.C. (1981).
Conditioning of simultaneous and serial
feature-positive discriminations. Animal Learning
and Behavior, 9, 293-303.