Transcript LECTURE_10-CRIT_OF_BEHAV

SKINNER’S “THEORY” OF
INSTRUMENTAL CONDITIONING
• Two-term contingency: R  SR
• Nature of reinforcer can vary: R  S [SR, Sr, S-R, S-r].
• 3-term contingency (Discriminative operant)
SD : R  SR (light: bar press  food)
S : R  SR (no light: bar press  food)
• Chaining of discriminative operants:
• Nature of discriminative stimulus can vary:
interoceptive, proprioceptive].
[exteroceptive,
SKINNER’S “THEORY” (con’t.)
• Contingency of reinforcement can vary: Rn/t  SR
• Schedule of reinforcement can vary: R  SR
– subject must emit n responses within a particular time frame t.
• Verbal Behavior. Behavior that is reinforced by a member of one’s
verbal community.
• Private events. Discriminative responding to proprioceptive or
interoceptive stimuli (stimuli under our skin, Sd : r  Sr)
Behaviorist Approach
• All learned behavior (human and animal)
can be explained by the principles of classical and
instrumental learning theory (2-factor learning
theory).
• Classical conditioning:
– assumes that CS’s and US’s can be paired arbitrarily.
– assumes that temporal contiguity of CS and US is necessary
and sufficient for establishing CR.
• Instrumental conditioning:
– assumes that responses selected for reinforcement are
arbitrary.
• No need to postulate mental processes.
EVIDENCE THAT QUESTIONED
BEHAVIORISTS’ ASSUMPTIONS
• “Misbehavior” of organisms
• Garcia’s experiment on taste aversion
• Autoshaping and omission training
• Blocking
• Rescorla’s experiment on predictiveness of US.
• Experiments on animal cognition
– Hunter’s definition of representation
– Radial maze
– Matching-to-sample
GARCIA EXPERIMENT ON TASTE
AVERSION
• Rats signalled about two types of noxious stimuli
(nausea and shock) by two types of CS (taste and
sound).
– taste: liquid sweetened with saccharine
– nausea: induced by lithium chloride
• Group I: Compound CS [taste & sound]  Shock
• Group II: Compound CS [taste & sound]  Nausea
• Effect of CS evaluated in 2-bottle choice test:
– Bottle 1: saccharine flavored water
– Bottle 2: water
• Group I: preferred sweet drink (natural preference)
• Group II: preferred water (avoid natural preference)
Blocking experiment
(Kamin)
• Training:
CS1  Shock:
CS1 + CS2  Shock
• Test:
CS1  fear
CS2  no fear
Predictable and Unpredictable
Occurrences of Food
_______
p(Food/K ey Light) > p(Food/K ey Light)
Predictable:
Key
CS:
Light
US:
Food
_______
p(Food/K ey Light) =p(Food/K ey Light)
Unpredictable:
CS:
US:
Key
Light
Food
Omission Training
SD (Key light):
R (Peck):
SR (Food):
EVIDENCE THAT QUESTIONED
BEHAVIORISTS’ ASSUMPTIONS
• “Misbehavior” of organisms
• Garcia’s experiment on taste aversion
• Autoshaping and omission training
• Blocking
• Rescorla’s experiment on predictiveness of US.
• Experiments on animal cognition
– Hunter’s definition of representation
– Radial maze
– Matching-to-sample
HUNTER ON
“REPRESENTATIONS”
...If comparative psychology is to
postulate a representative fact, ...it is
necessary that the stimulus represented
be absent at the moment of the response.
If it is not absent, the reaction may be
stated in sensory-motor term (Hunter,
1913, p. 21).
MATCHING-TO-SAMPLE
A. Matching-to-Sample
R
R
G
Peck
Peck
Peck (food)
Peck (no food)
A. Matching-to-Sample
R
Peck
B. Oddity
R
Peck (no food)
G
Peck (food)
RADIAL MAZE