Skinner and Behaviorism

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Skinner and Behaviorism

• No need for hypothetical constructs such as
  motivation and reward

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Emphasis on the observable and Measurable

• Minimization or exclusion of the unobservable
• Stimulus and Response Relationships (S-R
  relationships may account for behavior)

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Two major kinds of behavior that work together

• Conditioned behavioral responses
• and Operant Behavioral responses
• In both these areas Behavior (Learning) occurs
  due to the consequences of environmental stimuli.

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Classically Conditioned behaviors require an
unconditioned stimulus (US), an unconditioned
response (UR), a Neutral stimulus and
experiential pairings
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Classical Conditioning

• The Unconditioned stimulus (US) necessarily
  evokes an innate, often reflexive, response.
• Unconditioned Response (UR) - That innate
  reflexive response that naturally occurs
  following the US.
• The Conditioned Stimulus- a neutral stimulus,
  any stimulus that does not result in an overt
  behavioral response, that is repeatedly paired
  with the US.
• The Conditioned Response (CR) -After repeated
  pairings, the US and the neutral stimulus become
  associated and the organism will engage in the
  reflexive behavior in response to the CS

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After conditioning
One of Pavlovs dogs

• The US (formerly a neutral Stimulus) is now
  called a conditioned stimulus (CS) because it
  will now elicit the CR.
• The response to the CS is the conditioned
  response.

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Operant (or instrumental) Behavior

• Behavior that is more or less unconditioned
  (spontaneously emitted), that leads to an
  adaptive consequence.

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Operant conditioning

• Example- teaching a child to say please (requires
  a hungry child).
• parent ask child to say "please" when offered
  food.
• food is withheld until please behavior occurs.
• Following a "please" the food is served.
• Following a number of successful associations,
  please behavior will reliably occur.

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In this example the food acted as a Reinforcer
for the please behavior.Positive Reinforcers-
stimuli that follow a behavior and lead to
greater, more reliable future behavioral
responses.
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• Positive Reinforcers- lead to approach behaviors.
• What stimuli act as positive reinforcers?
• A primary reinforcer (unconditioned reinforcer)
  minimal experience necessary
• E.g.. sleep, food, air, water, and sex.

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Stimuli that act as Reinforcers (motivations) may
be learned

• secondary reinforcer (conditioned reinforcer)
• has acquired effects as a reinforcer by paired
  associations with a primary reinforcer or
  another conditioned reinforcer (such as money).
• Flashing lights and sounds paired with video game
  success, may eventually function as a reinforcer.
• Good grades..may be associated with a number of
  primary reinforcers and secondary reinforcers.

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At any moment of behavior what stimuli will be
reinforcers? Reinforcer relativity the Premack
Principle Behaviors that are the most
frequently occurring will serve as reinforcers
for less frequent behaviors.
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Negative reinforcers lead to escape or avoidance
behaviors.

• 1.      A rat is placed in a cage and immediately
  receives a mild electrical shock on its feet. The
  shock is a negative condition for the rat. The
  rat presses a bar and the shock stops. The rat
  receives another shock, presses the bar again,
  and again the shock stops. The rat's behavior of
  pressing the bar is strengthened by the
  consequence of the stopping of the shock.
• 2.      Driving in heavy traffic is a negative
  condition for most of us. You leave home earlier
  than usual one morning, and don't run into heavy
  traffic. You leave home earlier again the next
  morning and again you avoid heavy traffic. Your
  behavior of leaving home earlier is strengthened
  by the consequence of the avoidance of heavy
  traffic.

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And what about the role of Punishment?

• Punishers decrease future probability of behavior

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Behavior Theory can account for the development
of different behaviors (motivational direction)
and the strength of behaviors (Motivational
Intensity).

• Operant reinforcement not only shapes the
  topography of behavior, it maintains it in
  strength long after an operant has been formed. 
  Schedules of reinforcement are important in
  maintaining behavior. 

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Historical approach to study of Instrumental
behavior The operant chamber (the Skinner Box)

• A highly controlled environment.

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Responses recorded with a cumulative Recorder.
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Schedules of Reinforcement can account for
behavioral intensity.
(Pause and run pattern)

• Fixed ratio
• Reinforces behaviors after a specific number of
  responses (e.g. Every 2nd response). Normally a
  ratio schedule produces consistent work.
• Example Spending behavior associated with a
  vending machine that reliably provides snacks.

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Produces very high rates of behavior

• Variable ratio- the number of responses required
  for a reinforcer vary, and therefore the
  reinforcer is not predictable.
• Example Playing golf. It only takes a few good
  shots to encourage the player to keep playing or
  play again. The player is uncertain how good each
  shot will be, but the more often they play, the
  more likely they are to get a good shot.
• Gambling

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Fixed interval Reinforcers are delivered
following responses that occur following a
specific interval of time (e.g. Every 10
minutes). A reinforcer will be delivered
following that time period following the
response. The organism may develop a temporal
aspect to their behavior reflecting the
associated time interval..

• Scalloped pattern of responding reflects the
  approaching fixed interval opportunity. Following
• Reinforcer delivery response
• Rates clearly drop.
• Class study behavior?

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• Variable interval Time interval between
  reinforce availablity varies. Produces steady
  rates of behavior.
• In theory at least- Pop-test behavior

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EXTINCTION

• EXTINCTION - reinforcement discontinuation.
• An initial post discontinuation Extinction BURST
  of responding
• Then a behavioral decrease.
• Watch out for SPONTANEOUS RECOVERY.

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• Intermittently reinforced behavior is difficult
  to extinguish

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Behavioral theory can account for some tough
issues in Psychology
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Word task?
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• CONDITIONING OF A SUPERSTITION
• Suppose a naive subject is brought into a
  classroom and he sees the following The
  experimenter is standing in front of a counter, a
  hand switch connected to it. He instructs, "Say
  words any words at all, except for sentences.
  Try and earn as many points as you can." The
  subject then begins to say words and,
  occasionally, he (and the class) will hear a
  click of the counter as the subject earns points.
  Actually, the hand switch has nothing to do with
  whether the subject gets a reinforcement or not
  the counter is controlled by a timer. The subject
  gets reinforced, not because of anything he does,
  but solely with the passage of time.
• As the subject says words and gets reinforced,
  he, and members of the class, will form
  superstitious hypotheses. Some subjects may guess
  that reinforcement depends on saying plural
  words another will say it has to do with nouns,
  and so on. Some of the hypotheses (superstitions)
  will turn out to be quite involved, but all will
  be incorrect except the hypothesis that the
  reinforcement is noncontingent!

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Problems for S-R theories of Motivation

• Circular reasoning?

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Problems?

• Minimization of Internal and cognitive processes
• Account of Primary Reinforcersand URs- requires
  some internal process concept.
• since thinking cannot be observed, the theory of
  cognizant learning is unnecessary.
• Common sense experience that we can be
  skeptical?

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Final Notes

• Application Problemyou cant reinforce behaviors
  that do not occur or that rarely occur.
• In the larger context, behaviorist theory holds
  that free will is non-existent and that all of
  our actions are shaped by response to the
  external environment.

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POSTER PRESENTATIONS