Chapter 5: Basic Operant Principles
Reinforcement: Positive and Negative
Prolouge:
Edward L. Thorndlike conducted a study comparing the learning processes in animals
including 13 cats and 3 dogs
He placed an animal in an closed apparatus called a puzzle box that had a latch that
would open a door, enabling release from the box
The cats seemed more interested in gaining release to escape confinement than to get
food
A pattern of trial and error : trial- the time it took each animal to escape decreased
gradually from trial to trial. They didn’t suddenly discover a solution. Even after
several successful escapes, the animals would not run to and trigger the latch
immediately on being put in the box but seems to trigger it eventually while engaging
in other activities
Thorndike later talked about the law of effect- satisfying consequences such as
rewards or escape from unpleasant circumstances, strengthened stimulus-response
connections gradually in the process of learning
Learning processes in animals with an apparatus often called the skinner box
When a hungry rat depressed the lever a pellet of food dropped into the tray the food
was used as a reward which skinner called a reinforcer
Skinner demonstrated many features of reinforcement and its importance in learning
Defining reinforcement
To reinforce means to strengthen, increase or make pronounced
In operant conditioning REINFORCEMENT refers to the process in which a consequence of
a behavior strengthens that behavior making it more likely to occur in the future
The consequence is contingent on the behavior that is consequences occurs if the behavior
does
The object or event that serves as the consequence in reinforcement is called a
REINFORCER
Reinforcer is something the person wants or finds pleasant or satisfying
Reward- a prize, special payment
Reinforcer- when we push a switch to illuminate a room or smile at an attractive person who
then starts to converse with us
Reinforcer is more precise term it is used more frequently than reward in the rest of the book
Natural and Programmed reinforcement
NATURAL REINFORCER-happens spontaneously as a normal part of everyday events and
are not planned and given systematically to affect a behavior
o Examples: telling a joke is reinforced by the enjoyment other people express
o Reading labels on file folders is reinforced by accessing needed materials
o Eating food is reinforced by its good taste and hunger reduction
A special case of natural reinforcement is AUTOMATIC REINFORCEMT, in which a behavior
produces a reinforcer directly without other people plating a role Automatic reinforcement can maintain the repetitive /ritualistic behavioral excesses such as
flapping the hands of children with autism as well as the nervous habits such as nail biting
PROGRAMMED REINFORCER- are provided within a program of reinforcement with the
goal of increasing or strengthens specific behaviors
o Examples of programmed reinforcer are the rewards behaviors analysts use in teaching
social skills to children with autism
Positive and negative reinforcement
A behavior is followed by a consequence and the sequence can take two patterns positive and
negative
POSITVE REINFORCEMENT- the consequence involves presenting or adding a stimulus
called a POSITIVE REINFORCER, after the individual has performed the response
o EX: praise and snacks Jeremy mother gave him for his improvement in public speaking
When negative patterns occur a stimulus is subtracted for example if a boy has a tantrum in a
store because his mother refused to buy him candy and she relents the tantrums stops
Both people behavior received reinforcement- the boy’s tantrum behavior resulted in positive
reinforcement candy but the mothers’ behavior of relenting also got reinforced. The tantrum an
aversive stimulus stopped was subtracted. The mother’s relenting received negative
reinforcement making her more likely to relent for future tantrums
In NEGATIVE REINFORCEMENT- the consequence of the behavior – in this case, relenting
and buying candy – involves decreasing or removing an aversive stimulus the tantrum
o Examples: drinking alcohol to reduce unpleasant feelings
o Eating food to reduce feelings of hunger
Thorndike research with the puzzle box, the cats behavior of using the latch to open the door
was probably negatively reinforced by gaining release from the box
Negative reinforcement sometimes is confused with punishment
But in punishment the aversive stimulus such as a scolding occurs after the behavior on which
it is contingent
In negative reinforcement the aversive stimulus is present before the behavior that removes it
Positive means – (+) plus : Negative means – {-} minus
Positive means something is added where negative means something is subtracted
Unconditioned and conditioned reinforcement
UNCONDITIONED REINFORCER-(primary reinforcer) they function as Reinforcers even
when the individual has had no learning history with them
o Examples- unconditioned Reinforcers include – food, water, warmth, and the reduction
of pain when the individual is respectively, hungry, thirsty, cold or in pain
CONDITIONED REINFORCER- (secondary reinforcer) are stimuli that did not have the
ability to strengthen behavior until they became reinforcing as a result of learning
o Ex: animal trainers often develop conditioned Reinforcers to make rewards more easily
and quickly available when teaching tricks
o Examples od conditioned reinforcer: praise, television shows, music we like, good
grades in school, fashionable clothing, access to the internet, games, hobby activities and
jewelry
Types of positive Reinforcers
The many types of positive Reinforcers include: tangible or consumable items, activities,
social Reinforcers, feedback and tokens Tangible or consumable items
Tangible – means material objects we can perceive, such as toys, clothing or musical recordings
Consumable – things we can eat or drink such as candy, fruit or soft drinks
They both involve unconditioned or conditioned Reinforcers
o EX: when children at mealtime obey their parents instructions to wash their hands
before they may sit at the table and eat , food is the reinforcer for their behavior
Learning Theorist- CLARK HULL proposed that biological needs produce unpleasant internal
drives such as hunger that can be reduced directly by performing behavior that leads to a
relevant unconditioned reinforcer in this case food
Conditioned reinforcer such as money , work indirectly through their associations with
unconditioned reinforcer such as food
Three examples :
o Visual exploration as a reinforcer – BUTLER - there were monkeys in a cage that was
enclosed in a box that prevented the monkeys from seeing out , but it had a small door at
the box. The results showed that the door opening occurred at even higher rate when
they could see in the room a moving toy train
o Saccharin as a reinforcer- Saccharin is an artificial sweetener, has no calories.
Researchers examined saccharin as a reinforcer with rats that had been fed
unsweetened grain mash. The results were that the rats trained with the water
saccharin reinforcer ran six times faster then the trained with just plain water
o Brain stimulation as a reinforcer – OLDS and Milner – they implanted very thin
electrodes deep in rats brains to deliver tiny pulses of electoral current to specific
locations . the researchers then trained the subjects to press a lever and receive an
electrical pulse to the brain with each press . one rat made 1920 responses in a 1 hour
period for this reinforcer
Evidence suggest that Reinforcers can strengthens behavior: They reduce biologically based
drives directly or indirectly , they provide sensory stimulation , they involve performing
high-probability behaviors ( PREMACK principle), they have physiological effects
Activity reinforcer
Drawing pictures is one of many activities children often enjoy and do frequently when they
have a free choice, these kinds of activities are called high- probability behaviors
Premack proposed that one reason consequences are reinforcing is that they involve
performing high probability behaviors and these activities will work as Reinforcers
only for less frequent behaviors. This rule is called the PREMACK PRINCIPLE
The Premack principle appears to have some validity
Behaviors can increase peoples performance of infrequent behaviors
o EX: tooth brushing at a summer camp increased when the campus opportunities to
go swimming was contingent on brushing their teeth
o Children classroom conduct improved when their teacher made the opportunity to
play with toys, games and crafts contingent on increasing desirable behaviors and
decreasing undesirable ones
Using high- probability b
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