Transcript Lecture 4

Animal Cognition
Clive D. L. Wynne
Lecture 4
Cause & Effect
Reasoning
Cause and Effect Learning
Pavlovian conditioning
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Aka, Classical, Respondent or
Type II conditioning
Ivan P. Pavlov 1849-1936
Already famous as physiologist
studying digestion
•
Noticed dogs would salivate to
sight of scientist – ‘Psychic
secretions’
Pavlov’s dogs
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Originally
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Put food in dog’s mouth
Dog salivates
After doing this a few times
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Dog salivates just when it senses that food
is going to be put in mouth
Classical conditioning
A process by which an initially neutral
stimulus (the conditioned stimulus, CS)
comes to produce a response (the
conditioned response, CR) through being
repeatedly paired with a stimulus (the
unconditioned stimulus, US) that
produces a response prior to training (the
unconditioned response, UR).
Classical conditioning
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Food  Salivation
US
UR
Metronome  No salivation
CS
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Conditioning…
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Metronome: Food  Salivation
CS
UR
After conditioning…
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Metronome 
CS
Salivation
UR
Pavlovian terminology
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Unconditioned Stimulus (US) –
stimulus that produces a response
prior to training
Unconditioned response (UR) –
response to the US, occurs prior to
training
Conditioned stimulus (CS) – initially
neutral stimulus
Conditioned response (CR) – response
to the CS that only develops after CS
and US have been repeatedly paired.
Pavlovian procedures
Before conditioning
Conditioning
US-food
in mouth
UCR
salivation
US-food
in mouth
CS-tone
Orientation
but no
salivation
CS-tone
UCR
salivation
After conditioning
US-food
in mouth
CS-tone
UCR
salivation
CR
salivation
Conditioned Flavor Aversions
Eat something
Feel sick
Avoid that flavor
in future
CFA Experiment
Group
Stimulus
Outcome
Group A
Bright-noisy
water
Foot shock
Group B
Bright-noisy
water
Sickness
OK
Group C
Tasty
water
Foot shock
OK
Tasty
water
Sickness
Group D
Test water
Avoid
Avoid
CFA Experiment
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Some consequences can be more
readily associated with certain stimuli
Interval between CS and US can be
very long
Common experience is a form of
learning
Functions of CRs
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Prefiguring
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CRs enable individual to optimize
interaction with upcoming US.
Evidence in favor:
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Dog saliva has different composition
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CR saliva is thinner than UR – prepares
digestive system
Rats jump to shock US: freeze to CS
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Jump if snake attacks; freeze if snake detected
Functions of CRs
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Predator defense
CSs that predict danger USs evoke
predator defense reactions
Rats turn and flee from danger CS
But will freeze if learn that there is
no place to run to
Autonomic responses: increase heart
rate etc.
Diversity of Pavlovian cond.
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Animals learn about what predicts what
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Paramecia lean to withdraw when vibrations are
followed by electric shock
Honeybees associate odors, colors & shapes with
sucrose; but not with escape from box.
Marine snails (aplysia) associate light mantle
touch with shock to tail (close gill flap)
Lemon sharks learn to blink to light that predicts
mild shock close to eye – likewise goldfish.
Diversity of Pavlovian cond.
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Siamese fighting fish attack own reflection.
Conditioned to attack red light.
Leopard frogs conditioned to blink to light tough
on nostril followed by touch on eye – also toads
Bengal monitor lizards conditioned with flickering
light CS to food US attacked the light.
Collared lizards changed breathing, pulse and leg
movements in response to sound and light that
preceded electric shock.
Birds: especially pigeons
Mammals: especially rats, mice, rabbits, dogs &
humans; also cats and marsupials.
Diversity of Pavlovian cond.
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Hollis et al., 1997.
Male blue gouramis attack intruder males and may
repel egg-bearing females
Males exposed to 10-s white light followed by 5min exposure to female fish.
Came to make mating displays to light – were
better prepared for female – less aggressive.
At end of experiment Experimental group males
had sired > 1000 offspring each.
Control group < 50 offspring each.
Behavioral Consequences
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In Pavlovian Conditioning behavior is
elicited by stimuli (CR and UR)
But often behavior is controlled by its
consequences
Operant behavior
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The behavior operates on the environment
A.k.a. instrumental conditioning
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The behavior is instrumental in achieving
some consequence.
Edward Thorndike (18741949)
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Put animals in boxes and watched how
long it took them to escape
Essentially random behavior
Learning by trial and error
Thorndike’s Puzzle Boxes
Thorndike’s law of effect
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Consequences of an act determine whether
it will be repeated in the future
Behaviors followed by positive
consequences are more likely to be
repeated – strengthened – stamped in
Behaviors followed by negative
consequences are less likely to be repeated
– weakened – stamped out
Small’s Hampton Court Maze
Modern mazes
Skinner’s Learning by
Consequences
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Free Operant technique
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Subject free to make
response at any time – not
driven by reflex or structure
of apparatus (e.g., maze).
Operant conditioning
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Type of learning where future
probability of a behavior is
affected by its consequences
Skinner’s Learning by
Consequences
Diversity of Operant cond.
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More difficult to operant condition than Pavlovian
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because of need to find suitable reinforcement
v. difficult to operant cond. cold-blooded animals.
Tadpoles learnt to move away from a light to avoid a
shock
Anoles (lizards) learnt to escape shock by running to
another part of apparatus – also collard lizards and desert
iguanas
Queen triggerfish pressed plastic rod to drop food into
tank – also goldfish & koi carp
Birds: pigeons; doves; chickens; gulls & quail
Mammals: rats, mice, rabbits, cats, dogs, raccoons,
skunks, ferrets, minks, farm animals, marsupials,
primates, humans.
Reasoning
Spatial Reasoning
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Tolman &
Honzig, 1930
3 paths –
blockable at
points shown.
Once familiar
with the maze,
rats always
chose the
shortest
remaining path
after a blockage
Spatial Reasoning
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Wolfgang Köhler, 1925
Transparent barriers (fence of wire netting)
Dog, girl just > 1 yr, chickens, chimpanzees
goal
start
Spatial Reasoning
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Bruno Poucet et al., 1983
Cats choose shorter path
But only if barrier opaque.
In extended tests cats only take shorter
route if does not involve larger original
detour angle.
Reasoning about Gravity
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Hood et al.,
1999
Insight
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Wolfgang Köhler,
1921
Chimpanzees on
Tenerife in WW1
Banana hung out of
reach on roof
Köhler impressed by
the flash of insight
All six apes vainly endeavored to reach the fruit by
leaping up from the ground. Sultan soon relinquished
this attempt, paced restlessly up and down, suddenly
stood still in front of the box, seized it, tipped it hastily
straight towards the objective, but began to climb upon it
at a (horizontal) distance of ½ meter, and springing
upwards with all his force, tore down the banana.
More Insight
Pigeon Insight
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Robert Epstein et al., 1984
Pigeon reinforced for moving
box to a green spot in the
center of the chamber
On other trials for standing on
a box already placed in the
center of the chamber and
pecking at the plastic banana
hanging from the ceiling.
 In test session pigeon was faced with the problem of pecking the
banana while the box was at the side of the chamber and there was
no green spot to move the box to. Pigeon quickly solved the problem
by moving the box to the center of the chamber and mounting it to
peck the banana.
Insight
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Elisabetta
Visalberghi & Luca
Limongelli, 1994
 Only 1 of 4 Capuchins learnt
to avoid the trap over 140
trials.
 When trap was inverted still
treated it as dangerous.
 2 of 5 chimps successful
 Only 1 chimp behaved
appropriately when the trap
was moved up and down the
tube.
Tool use
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Ant-lions throw sand on prey
that comes in their pits
Japanese macaques use water
to separate sand from food
grains
Open mollusk shells
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Sea otter smash them on stones
held against their chests
Gulls drop them onto stones from
a height
Hermit crabs grab sea
anemones and use them to
repel enemies
Tool use/creation
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Tetsuro Matsuzawa.
Bossou chimpanzees
hammer/anvil nut
cracking
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1 on map
 Other chimp
communities
have
different
tools
 Termite
fishing
 Water
Tool creation
Series Reasoning:
Transitive Inferences
Bryant & Trabasso (1974)
Children
A
B
C
D
E
Kate is cleverer than May:
May is cleverer than Jane.
Who is the cleverest--Jane, Kate or May ?
Squirrel Monkeys
REWARDED NON-REWARDED
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McGonigle & Chalmers (1977)
Pigeon Stimuli
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Pigeon Data
Percent correct responses
100.00
Phase 1
Phase 2
Phase 3
Phase 4
90.00
80.00
70.00
60.00
Pigeons
Model
50.00
A
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B
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B
+
C
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C
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D
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D
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E
-
A
+
B
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B
+
C
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C
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D
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D
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E
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X A B C
+ + + +
A B C D
- - - Pair/ Phase
D
+
E
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E
+
F
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X
+
A
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A
+
B
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B
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C
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C
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D
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D
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E
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E
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F
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F
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X
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Counting: Sheba (chimp)