1. Stimulus Control

2. Stimulus Control of Behavior Having stimulus control means that the probability of the behavior varies depending upon the stimuli present. If a behavior is under stimulus control then – The behavior happens when the stimulus is present – The behavior doesn’t happen when the stimulus is absent Most of our behavior is under stimulus control – A person that contributes to charity generously while in church may watch every penny spent while at work

4. Stimulus Control Stimulus Discrimination – Definition: Degree to which antecedent stimuli set the occasion for particular responses precise degree of stimulus control E.g., Man has beard and is Daddy; Man has beard and is Uncle Eddie – Stimulus discrimination is taught by using discrimination training procedures such as differential reinforcement

5. Stimulus Control Stimulus Generalization – Definition: When a response is reinforced in the presence of one stimulus there is a general tendency to respond in the presence of new stimuli that have similar physical properties ore have been associated with the stimulus. loose degree of stimulus control E.g., All men with beards are Daddy – Stimulus discrimination is taught by using generalization training procedures, reinforcing responses to many similar stimuli.

6. Development of Stimulus Control Stimulus discrimination training requires – One behavior – Two antecedent stimulus conditions (the S D and the S  ) Responses that occur in the presence of the S D are reinforced (thus, the response increases in the presence of the S D ) Responses that occur in the presence of the S  are not reinforced (this, the response decreases in the presence of the S   – Can also result in a lesser amount or quality of reinforcement

7. Development of Stimulus Control Example: Reinforcing a child’s saying “red” when someone asks “What’s your favorite color?” and witholding reinforcement if they said “red” when asked “ What’s your name?”

8. Response: “red” Reinforcer: “Super! You said red!” S D : “What’s your favorite color?” S Δ : “What’s your name?” No praise

9. Differential Responding When a child’s behavior comes under the control of the S D, – We say the S D has acquired stimulus control over the child’s behavior – So the verbal stimulus “What’s your favorite color?” gains stimulus control over the response “red” – why? – And the child is discriminating or responding differentially

10. Stimulus Generalization When a response is reinforced in the presence of one stimulus, But: that same type of behavior tends to be evoked by stimuli that share similar physical properties with that controlling antecedent stimulus

11. Stimulus Generalization If you teach “green” using this color circle … Student’s most likely to say “green” Student’s less likely to say “green” (discrimination)

12. Stimulus Generalization Stimulus Generalization is more likely when: – Stimuli that are highly similar to the original stimulus are presented. – E.g., similar people, materials, or settings The more similar the novel person, materials, and setting are to the training person, materials, and setting…

13. Discrimination vs. Generalization Essentially opposite processes – As discrimination increases, generalization decreases – As discrimination decreases, generalization increases Discrimination – Responding differently to 2 or more stimuli – Tight degree of stimulus control Generalization – Responding similarly to 2 or more stimuli – Loose degree of stimulus control

14. Stimulus Discrimination and Stimulus Generalization are a Continuum Stimulus Discrimination Stimulus Generalization Generally, as the training and test stimuli become more different responding will decline, Produces a generalization gradient

15. How to test generalization TrainGeneralizationTest T+ T = 1000hz tone No reinforcers Present tones of varying frequencies and examine lever pressing in response to each tone

16. Generalization Gradient Guttman & Kalish (1956) – pigeons reinforced for pecking a 580 nm lit key (orange-yellow) (S+) on a VI schedule – A test session was then given where many different colored key lights were presented in extinction S+

17. Interpreting Generalization Gradients Pigeons trained to peck a moderately bright light (S+) to get food. (S- = dim light) After asymptote is reached, present occasional non- reinforced probe trials at various wavelengths or levels of brightness.

18. Excitatory and inhibitory gradients Excitatory gradients form around the CS+; show where responding is MOST likely Inhibitory gradients also form; show where responding is least likely e.g., Pigeons trained to peck at a 800 hz tone (S+), with a 500 nm light S-.

19. Peak Shift Phenomena where the peak of the generalization curve shifts AWAY from the S- – Means that the most responding does not occur for the S+ – But slightly offset from the S+ and away from the S- – Question is WHY!

20. Peak Shift Effect – Hanson (1959)

21. Spence’s Theory Spence: Peak shift occurs because of the summation of the excitatory and inhibitory curves – Result is that the most responding is slightly in favor of the S+ – Not as strong of suppression for S- – Thus, get shift away from S- – Just a math phenomenon

22. Spence’s Theory to Account for Peak Shift S+ S-

23. Interdimensional theory Kohler’s Transposition or Interdimensional theory – The animal learns a conceptual rule – “Not” the S- but is the S+ – Thus, when given generalization stimuli, take whatever is the most “not” S- – Shift away from S+ occurs Learning a concept: always choose larger or greener, etc.

24. Interdimensional discrimination Discrimination: S+ = 555nm Light; S- = Tone

25. Test of Theories Choose between squares: S+ S- Situation: 100 cm 2 60 cm 2 original training 250 cm 2 150 cm 2 Test 1: Spence’s test 500 cm 2 250 cm 2 Test 2” Kohler’s test 1000 cm 2 500 cm 2 ?????? Spence's prediction: will choose closest to original S+ Transposition or interdimensional: choose larger

26. Which is correct? tests for transposition yield evidence supporting transposition tests for generalization yield evidence supporting Spence probably: both effects working part of the time

27. What is a stimulus Any sensory event that elicits a response – Not necessarily the response you want – Need to know that that rat perceives the stimulus Establishing a cue – Classically condition (cue to cue) – Operant conditioning: response to reinforcer, then add predictive cue for contingency

28. Why Teach Discriminations? Discrimination is a fundamental process that controls behavior. Discrimination allows us to differentiate when reinforcement is available for specific responses.

29. Why Teach Discriminations? Many essential tasks require discrimination skills – Reading. – Labeling Objects. – Following directions. – Following activity schedules. – Greeting people. – Self-care skills.

30. Basic Problem of Discrimination Training Discrimination training teaches learners to perform a specific response in the presence of a specific stimulus and not to perform that response in the presence of other stimuli.

31. Discrimination Training Many individuals with developmental disabilities have difficulty learning discriminations Stimuli are compound (they consist of different elements) – It may be difficult to control which element(s) of the stimulus exert control over behavior – We must be careful how we teach and what stimuli we use!

32. Stimulus Compounding All stimuli are compound. – They consist of many different elements. It is difficult to control which element or elements of the stimulus exert control over behavior. – need to be careful how we teach and what stimuli we use.

33. 2 Types of Discriminations. Simple Discriminations. – Non-Conditional Discrimination. Conditional Discriminations. – Matching-to-sample. – Arbitrary Discrimination.

34. Simple Discrimination Stimulus is present or not present – One picture on the table that’s a “cat” Say touch “cat” and they do – Not very useful for children with autism – That kind of trial becomes stimulus independent which is what you DON”T want to happen

35. Conditional Discrimination A response to a given stimulus is followed by a reinforcer if and only if another stimulus is present Said another way…a stimulus is discriminative for reinforcement or not, depending on (conditional on) the presence of another particular antecedent Often taught via Match-to-Sample procedures – Many programs consist of Identity Matching – matching identical stimuli: Objects Pictures Letters Shapes Colors Numbers

36. Match-to-Sample Sample Learner 1 st responds to sample (conditional stimulus) Then responds to one of the comparison stimuli S D /S + S Δ /S-

37. Match-to-Sample S D /S + Sample (Conditional Stimulus) S D /S + Sample (Conditional Stimulus)

38. Establishing New Forms of Conditional Stimulus Control Identity matching (single mode) – Visual: visual – Auditory: auditory Arbitrary matching (multimodal) – Visual: auditory – Auditory: visual – Auditory: tactile

39. Arbitrary Matching Stimuli are not physically identical Examples – Match non-identical visual stimuli Object to pic, printed word to picture, object to printed word – Match auditory stimulus to visual stimulus (“Receptive Identification”) – Others?

40. Receptive Picture ID “flower” “baby” SD/S + Sample SD/S + Sample

41. Discrimination in the Laboratory. Many laboratory discrimination procedures have focused on understanding exactly which stimuli or which aspects of stimuli control responding. Several laboratory procedures have been developed that allow us to isolate these stimulus control factors. – Matching-to-Sample. – Equivalence Class Formation.

42. Concept Formation Definition: Complex stimulus control that results in generalization within a class of stimuli and discrimination between classes of stimuli (Keller & Schoenfeld, 1950).

43. Two Procedures to Teach Concept Formation: Simultaneous Discrimination: – Definition: The concurrent presentation of multiple stimuli Successive Discrimination – Definition: The successive presentation of stimuli In applied settings, simultaneous discrimination training typically used – The individual has access to all relevant stimulus cues at 1 time – An on the spot comparison of choices is permitted – Produces better generalization (Schroeder & Baer, 1972)

44. Real World Teaching Procedures. Real World teaching is more complex than the laboratory. Suggestions for improving discrimination training – Evaluate stimuli carefully to promote control of relevant antecedent cues – Rotate stimulus placement randomly – Change auditory stimuli frequently – Be sure that the S+/S- functions of stimuli change randomly – Teach with a variety of stimuli to promote discrimination between categories (and generalization within categories) Never, never teach in isolation!!

45. Stimulus Class Stimulus Class: set of stimuli that have a common effect on behavior (evoke the same response class) These would probably be in the same stimulus class for most people

46. Concept Formation Complex stimulus control that results in: – Generalization within a class of stimuli and – Discrimination between classes of stimuli

47. Stimulus Equivalence Emergence of accurate responding to untrained and nonreinforced stimulus- stimulus relations – Following the reinforcement of responses to some stimulus-stimulus relations 3 aspects – Reflexivity – Symmetry – Transitivity DO G “dog” A B C

48. Reflexivity In the absence of training, person selects an identical stimulus (AKA Generalized identity matching) Logic is…A = A For example – Without specific training, the person matches

49. Symmetry After being taught to match A to B, person can match B to A (without training) Logic is…If A = B, then B = A For example – After being taught to matchto – Person can match to DOG

50. Transitivity Critical test for stimulus equivalence – if you get transitivity, the stimuli are members of an equivalence class After being taught to match A to B and B to C, person can match A to C (without training) Logic is…If A = B and B = C, then A = C For example… – After being taught to match to AND to “dog” – Person can match to “dog” to DOG

51. Factors Affecting the Development of Stimulus Control Reinforcement – Differential reinforcement with rich schedules of reinforcement – Reinforce stimuli that are part of concept – Must learn to attend to specific elements of the stimuli, not just the whole stimulus Preattending Skills – Type of instructor or materials – sitting up tall, ready to work (awake and functioning!) – no stereotypy or other misbehavior

52. Factors Affecting the Development of Stimulus Control Stimulus Presentation – Specificity of directions Should relate to response definition – Opportunity to response Frequent, active opportunities to respond (active student learning) correctly leads to higher rates of academic achievement – Pacing of response opportunities Higher pace often leads to superior performance and less off- task behavior

53. Factors Affecting the Development of Stimulus Control Salience of the stimuli – Influences attention and ultimately the development of stimulus control – Dependent on the capabilities of an individual, the past history of reinforcement, and the situation – Multiple intelligences: some respond to instructional stimuli in the visual modality more than the oral. – This research has generated mixed results but it is important to rule out sensory deficits and assess modality strength

54. Factors Affecting the Development of Stimulus Control Masking and overshadowing – Masking –even though one stimulus has control over behavior, another stimulus blocks that control from being expressed E.g., Student knows answer but won’t answer in front of peers – Overshadowing –the presence of one stimulus condition interferes with the acquisition of control by another stimulus E.g., hallway may be more interesting that teacher’s presentation in the front of the classroom Ways to overcome include to make changes to physical environment, make instructional stimuli as intense and centrally located as possible, reinforce behavior in the presence of the instructionally relevant stimuli

55. What is a stimulus Any sensory event that elicits a response – Not necessarily the response you want – Need to know that that rat perceives the stimulus Establishing a cue – Classically condition (cue to cue) – Operant conditioning: response to reinforcer, then add predictive cue for contingency

56. Shaping the cue Need to shape the response to the cue Introduce the stimulus cue right when the behavior occurs – Not as it is starting, not after – E.g., for a dog to learn “sit”, not when it is walking, but when it starts to sit. – BUT: click once the behavior is underway, not when the behavior is finished – Then, only introduce the cue when the dog is NOT doing the behavior Give the cue Get the behavior click

57. Four rules for stimulus control Behavior occurs immediately upon presentation of the cue stimulus Behavior never occurs in absence of stimulus Behavior never occurs in response to another stimulus No other behavior occurs in response to the stimulus

58. Transferring stimuli Once establish one cue, can add a second cue for the same behavior – Again, use only for THAT behavior – Keep stimuli separate. – E.g., does down mean stop jumping on me or lie down on the ground?

59. Prompting Prompts used to increase probability that organism will engage in correct response Use during discrimination training – S D or S + : in presence of this stimulus, do the behavior – S or S-: in the presence of this stimulus, do NOT do the behavior Function of prompts is to produce instance of correct behavior so it can be reinforced

60. Types of Response prompts Response prompts: behavior of another evokes desired response in presence of S D Verbal prompts: voice command Gestural prompts: physical movement or gesture of trainer Modeling prompts: observe model and imitate (not really used with rats) Physical prompts: physically assisting rat to engage in behavior

61. Types of Stimulus prompts Stimulus prompts: change in stimulus or addition/removal of stimulus increases likelihood of desired response in presence of S D Within-Stimulus prompts: change the salience of a prompt – Bigger or smaller – Louder or softer – More or less Extra-stimulus prompts: – Adding a stimulus to increase likelihood of correct discrimination – Picture prompts – Putting line of food pellets for rat to follow

62. Aversive cues Use aversive to STOP behavior E.g., “no”, a sharp noise, a table slap correction Good for dangerous behaviors Potential downside: – Squelch behaviors – Organism is startled, now won’t move – More likely to bite/nip/freeze

63. Limited holds and anticipation Limited hold: – Reinforcer only available in a narrow window Either take it now, or lose it Often used to avoid stashing or lazy choice – If do behavior, can get reinforcer within x seconds or less, otherwise lose it. Anticipatory behaviors occur before the cue – If occur, cancels the trial – Withdraw target stick and even put rat in “time out”

64. Behavior chains One behavior can be a cue for the next response This is a behavior chain – E.g., run through the tunnel, over the balance beam and then through the weave poles Can teach forward chain: – Start with first, then add second, third, etc. – Reinforce after successful behavior for criterion Or backwards chain: – Start with last response, then next to last, and so on – Reinforce after successful behavior for criterion

65. Generalization May want organism to engage in behavior in many settings/situations/cues E.g., go over balance beam whether it is on the desk or in either of the two big boxes Stop at any red traffic light Must train so that the cues to which the subject attends are the ones relevant to the task, not the setting

66. Fading prompts Important to fade prompts – Want behavior to occur to cue only – Shows mastery of behavior Behavior flows well Behavior occurs at high rate (or low rate if that is goal) Occurs evenly and consistently – Fading prompts allows fluency Behavior occurs when, where, how well you want it Can generalize to appropriate stimuli Can discriminate irrelevant stimuli

67. Fading prompts Several ways to fade prompts: – Transferring stimulus control Remove one stimulus cue, then another – Fading across different types of prompts or fading across prompts Least to most: fade least invasive prompt first Most-to-least fading: fade most invasive prompt first – Prompt delay Delay the prompt Increase delay until behavior occurs before prompt would have been given

68. Herb Terrace: Errorless Learning instructional design introduced by B.F. Skinner Skinner said: "errors are not necessary for learning to occur. Errors are not a function of learning or vice-versa nor are they blamed on the learner. Errors are a function of poor analysis of behavior, a poorly designed shaping program, moving too fast from step to step in the program, and the lack of the prerequisite behavior necessary for success in the program." can also be understood at a synaptic level: principle of Hebbian learning: "Neurons that fire together wire together".

69. Traditional Procedure subject learns to associate one stimulus, S+ (positive stimulus), with reinforcement (e.g. food) and another, S− (negative stimulus), with extinction (e.g. absence of food). For example, red key (S+), green key (S−). Traditional procedures: pigeon trained to – initially trained to peck a red key (S+). – When responding consistently to the red key (S+), a green key (S−) would be introduced. – At first pigeon would also respond to the green key (S−) – gradually responses to the S- would decrease, because they are not followed by food, so that they occurred only a few times or even never.

70. Terrace Method Terrace (1963): found that discrimination learning could occur without errors: – training begins early – the S+ and S− were initially presented with different brightness and duration, S+ would appear for 5 s and fully red S− would appear for 0.5 s and dark. – duration of the S− and its brightness gradually increased until the keylight was fully green for 5 s.

71. Example: teach S+ = red; S- = green Teaching red vs. green discrimination – S- presented for only 5 or so seconds – S+ presented for 3 minutes – S- begins as unlit (dark) key: pigeons much less likely to peck it S- gradually fades to green key human example: teaching MR children sight words – word + picture on slide – gradually fade the picture, leaving only the word

73. RAT

80. Does it work? highly effective in reducing the number of responses to the S− during training. In Terrace's (1963) experiment: – Ss trained with the conventional discrimination procedure averaged over 3000 S− error responses during 28 sessions of training – Ss trained with the errorless procedure averaged only 25 S− (errors) responses (same # sessions)

81. Additional Benefits (Terrace, 1972) Errorless learning procedure improves long-term discrimination performance S− does not become aversive and so does not elicit "aggressive" behaviors, as it often does with conventional training S− does not develop inhibitory properties; Positive behavioral contrast to S+ does not occur. “By-products" of conventional discrimination learning do not occur with the errorless procedure.

82. Cognitive Research Supports! Studies of implicit memory and implicit learning provided additional theoretical support for errorless learning methods – Brooks and Baddeley, 1976, Tulving and Schacter, 1990. Implicit memory – known to be poor at eliminating errors – can be used to compensate when explicit memory function is impaired. In experiments on amnesiac patients: – errorless implicit learning more effective – reduced the possibility of errors "sticking" in amnesiacs' memories

83. Feature Positive Effect

84. Heart and Jenkins, 1974 Asymmetry in the pigeon's learning of discriminations based on the presence versus absence of a single distinguishing feature.

85. Feature Positive Effect several limitations on effectiveness of discrimination training: – discrimination will not occur if animal cannot detect difference between stimuli – animal won't form discrimination if not attend to proper stimuli the stimulus that an animal attends to is determined by many factors, including: species differences salience of stimuli past experiences

86. Feature Positive effect: Hearst and Jenkins (1974) basic experiment: – pigeons given 2 stimuli simultaneously – S+ = lighted key w/dark spot – S- = lighted key w/no dark spot – looked at discrimination ratio: key pecks to S+/ total key pecks S+ S- thus: perfect dsicrimination ratio = 1.0 no discrimination = 0.5 – results of initial experiment: pigeons quickly learned to discriminate

87. Feature Negative Effect then: switched stimuli around: – S+ = lighted key w/NO dark spot – S- = lighted key w/dark spot found NO discrimination in this case Why? Feature Negative effect!

88. Feature Positive Effect

89. S+

90. S-

91. S+

92. S-

93. S+

94. S-

95. S+

96. Feature Negative Effect

97. S+

98. S-

99. S+

100. S-

101. S+

102. S-

103. S+

104. One more try!

105. S-

106. S+

107. S-

108. S+

109. S-

110. S+

111. S-

112. S+

113. S-

114. S+

115. S-

117. So, what is the concept?

118. An Unusual Paragraph! How quickly can you find out what is so unusual about this paragraph? It looks so ordinary that you would think that nothing is wrong with it at all, and, in fact, nothing is. But it is unusual. Why? If you study it and think about it, you may find out, but I am not going to assist you in any way. You must do it without coaching. No doubt, if you work at it for long, it will dawn on you. Who knows? Go to work and try your skill. Par is about half an hour.

119. A Clue The author, Eliot Hearst, could not add his name to the paragraph and maintain the concept!