B'F' Skinnner

1
B.F. Skinnner

• Radical and then Modern Behaviorism

2
Burris Fredric Skinner
3
Burris Frederic Skinner

• Born in Penn.
• BA degree in English from Hamilton College
• Masters/PhD from Harvard in 1930, 1931
• Taught at Univ of Minnesota 1936-1945
• Behaviors of Organisms, 1938
• 1945 to Indiana University
• 1948 to Harvard there until his death in 1990
• Several important human rights books
• Beyond Freedom and Dignity
• Walden Two
• Enjoy Old Age
• 2 daughters one is psychologist Julie Vargas
  (runs autism program at WVU) and a pianist

4
Why Behaviorism

• defines "behavior" as what the animal is
  (observed to be) doing.
• avoid anthropomorphizing or implying conceptual
  schemes
• Simply describe what the animal is doing
• avoids preconceived notions and concepts about
  the animal's behavior

5
Narration as a descriptor defining what is
behavior

• narrate what the animal is doing- running frame
  of reference
• stimulus refers to environment
• correlated behavior is the response
• reflex observed relation between the stimulus
  and response
• (implies lawfulness)
• is a fact, not a theory
• not want to "botanize" - but come up with general
  laws of behavior

6
Several laws of classical conditioning

• uses to distinguish from operant behavior
• Static laws of the Reflex Really discussing
  classical conditioning here
• law of threshold the intensity of the stimulus
  must reach or exceed a certain critical value in
  order to elicit a response
• law of latency an interval of time elapses
  between the beginning of the stimulus and the
  beginning of the response
• law of magnitude of the response the magnitude
  of the response is a function of the intensity of
  the stimulus
• law of after discharge the response may persist
  for some time after the cessation of the stimulus
• law of temporal summation prolongation of a
  stimulus or repetitive presentation within
  certain limiting rates has the same effect as
  increasing the intensity

7
several laws of classical conditioning

• Dynamic laws of reflex strength
• law of refractory phase immediately after
  eliciation the strength of some reflexes exists
  at a low, perhaps zero, value. It returns to its
  former state during subsequent activity
• law of reflex fatigue the strength of a reflex
  declinces during repeated elicitation and returns
  to its former value during susequent inactivity
• law of facilitation the strength of a reflex may
  be increased through presentation of a second
  sitmulus which does not itself elicit the
  response
• law of inhibition the strength of a reflex may
  be decreased through the presentation of a second
  stimulus which has no other relation to the
  effector involved
• also discusses law of conditioning of Type S and
  law of extinction of Type S

8
Distinguishes between PAVLOVIAN and OPERANT
conditioning

• Operant behavior is EMITTED not elicited
• static laws DO NOT apply to operant behavior
• Remember still in day when CC does NOT equal OC
• Believed were different kinds of learning
• CC visceral muscles
• OC skeletal responses

9
Dynamic laws of Type R behavior

• HIS version of the Law of Effect
• law of conditioning of Type R if the occurrence
  of an operant is followed by a presentation of a
  reinforcing stimulus, the strength is increased
•   -notice that conditioning strength of the
  operant
•  
• law of extinction of Type R behavior if the
  occurrence of an operant already strengthened
  through conditioning is not followed by the
  reinforcing stimulus, the strength is decreased
• can get stimuli that are correlated with R-S
  connections thus can set the occasion for the
  R-S contingency

10
The reflex reserve

• reflex reserve total available activity for an
  animal
• there is a relation between
• the number of responses appearing during the
  extinction of an operant and
• the number of preceding reinforcements
• changes in drive do not change the total number
  of available responses,
• although the rate of responding may vary greatly
• emotional, facilitative, and inhibitory changes
  are compensated for by later changes in strength

11
Interaction of reflexes

• important in that responses not occur in
  isolation
• law of compatibility two or more responses which
  do not overlap topographically may occur
  simultaneously without interference
• law of prepotency with two reflexes overlap
  topographically, and the responses are
  incompatible, one response may occur to the
  exclusion of another
•  
• law of algebraic summation the simultaneous
  elicitation of two responses utilizing the same
  effectors but in opposite directions produces a
  response the extent of which is an algebraic
  resultant

12
Interaction of reflexes

• law of blending two responses showing some
  topographical overlap may be elicited together
  but in necessarily modified forms
• law of spatial summation when two reflexes have
  the same form of response, the response to both
  stimuli in combination has a greater magnitude
  and a shorter latency
• law of chaining the response of one reflex may
  constitute or produce the eliciting or
  discriminative stimulus of another
• law of induction a dynamic change in strength of
  a reflex may be accompanied by a similar but not
  so extensive change in a related reflex, where
  the relation is due to the possession of some
  common properties of stimulus or response

13
Defines properties of a class of a reflex

• under what conditions does the R occur?
• in operant conditioning what are the defining
  characteristics for reinforcement
• Under what stimulus conditions does a response
  occur? What are the results?
• Really the ABCs of operant behavior!
• What does the animal DO to get reinforced
• must show a correlation between R and S
• We will argue later that this must be a
  contingency!
• must show that dynamic laws apply

14
Defining Skinner's methodology

• direction of inquiry
• inductive rather than deductive
• hypotheses declared to direct the choice of facts
• not necessary, but guide what is a useful vs
  useless fact
• The organism
• Skinner wants to limit to one single
  representative sample
• the white rat- many advantages in terms of
  control
•  
• The operant
• use bar pressing
• Skinner box
• again- assume that is equivalent to any other
  response
• easy to measure- reliable, controllable, etc.

15
Skinner box Pigeon pecks or rat bar presses to
receive reinforcers
16
System of notation

• S stimulus
• R response
• S.R respondent
• sR reinforcer
• properties of term indicated with lower letters
• Rabc response with properties a b and c
• superscripts comment upon term- place, formula,
  etc.
• e.g. S1 or SD
• also composite stimuli S1SD
• --gt is followed by
• Now can analyze a chain or sequence of behavior
  and string together to make "behavior sentences"

17
Important to control Extraneous Factors

• use maximal isolation e.g. sound attenuating
  chamber
• control "hunger" with deprivation, etc.
• Usually around 80 free feeding
• This is higher today (85-90)
• Maintains a constant hunger
• standardize feeders and reinforcers
• control light/day cycles, etc.
•  as much experimental control as possible to
  reduce variance in experiments

18
The Cumulative REcorder

• Measuring the Behavior
• important characteristics of measurement
• definition of behavior as that part of activity
  of the organism which affects the external world
• the practical isolation of the unit of behavior
• definition of a reponse as a class of events
• demonstration that the rate of responding is the
  principal measure of the strength of an operant
• cumulative record
• Responses accrue or are cumulative
• What happens if the line goes down?

19
Reinforcers vs. PunishersPositive vs. Negative

• Reinforcer rate of response INCREASES
• Punisher rate of response DECREASES
• Positive something is ADDED to environment
• Negative something is TAKEN AWAY from
  environment
• Can make a 4x4 contingency table

20
Reinforcement Punishment Positive Positive
Reinforcement (Positive) Punishment Add make
bed--gt10cent hit sister-gtspanked Stimulus Negat
ive Negative Reinforcement Negative
Punishment Remove make bed-gt Mom stops hit
sister-gtlose TV Stimulus nagging
21
Parameters or Characteristics of Operant Behavior

• Strength of the response
• With each pairing of the R and Sr/P, the
  response-contingency is strengthened
• The learning curve is
• Monotonically ascending
• Has an asymptote
• There is a maximum amount of responding the
  organism can make

22
(No Transcript)
23
Parameters or Characteristics of Operant Behavior

• Extinction of the response
• Remove the R? Sr or R?P contingency
• Now the R ? 0
• Different characteristics than with classical
  conditioning
• Animal increases behavior immediately after the
  extinction begins TRANSIENT INCREASE
• Animal shows extinction-induced aggression!
• Why?

24
(No Transcript)
25
More parameters

• Generalization can occur
• Operant response may occur in situations similar
  to the one in which originally trained
• Can learn to behavior in many similar settings
• Discrimination can occur
• Operant response can be trained to very specific
  stimuli
• Only exhibit response under specific situations
• Can use a cue to teach animal
• S or SD contingency in place
• S- or S contingency not in place
• Thus SD R?Sr

26
Schedules of Reinforcement

• Continuous reinforcement
• Reinforce every single time the animal performs
  the response
• Use for teaching the animal the contingency
• Problem Satiation
• Solution only reinforce occasionally
• Partial reinforcement
• Can reinforce occasionally based on time
• Can reinforce occasionally based on amount
• Can make it predictable or unpredictable

27
Partial Reinforcement Schedules

• Fixed Ratio every nth response is reinforced
• Fixed interval the first response after x amount
  of time is reinforced
• Variable ratio on average of every nth response
  is reinforced
• Variable interval the first response after an
  average of x amount of time is reinforced

28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
More parameters

• Shaping
• Final behavior must be within repertoire of
  organism
• Break behaviors into smallest component
• Chain up or down
• Secondary reinforcement
• Stimuli can be paired with primary reinforcer
• E.g. money
• Generalized reinforcers
• Reinforcers reinforce many behaviors
• E.g., money reinforcers many, many behaviors
• Chaining
• Make a chain of behaviors
• E.g., 1 behavior leads to another to another to
  anothermakes a chain of behavior.