Download presentation
Presentation is loading. Please wait.
Published byStella Floyd Modified over 9 years ago
3
Operant vs. Classical Operant responses understood by comprehending the consequences they produce vs. Pavlovian responses may have environmental effects, but this is not what controls them
4
Edward Thorndike Acquisition of Goal-directed responses. Law of Effect - behavior occurs in a random, trial-and-error fashion. Consequences of a behavior can increase or decrease the future probability of that behavior. 1874-1949
5
Trials Escape Time Cat Puzzle Box
6
Law of Effect Responses followed by a satisfying outcome will strengthen the association between the situation and the response. Responses followed by a dissatisfying outcome will weaken the association between the situation and the response.
7
Law of Effect Press lever Escape from boxTime 1: Time 2: Placed in box higher probability of pressing lever Strengthens box-lever press association Pull string Remain in boxTime 1: Time 2: Placed in box lower probability of pulling string Weakens box-string pulling association
8
Discrete-Trial Procedures W. S. Small (1900) – used the maze as a tool to study operant learning in rats. “complex” maze; measures = running speed, latency to reach goal.
9
Hampton Court Palace Maze
10
T-Maze Start Food No Food
11
Straight Alley “Maze” StartFood
12
Operant (Instrumental) Conditioning The Skinner Box:
13
Lever 2 Stages of training:1. Magazine training 2. Shaping = reinforcement of successive approximations
14
Lever
19
Free-Operant Procedures Discrete-trial procedures provide animal with limited opportunities to respond. Free-operant procedures allow the animal to perform the instrumental response repeatedly without constraint.
20
Discrete-Trial Operant Procedure Lever Light = Discriminative stimulus (S D )
22
Acquisition and Extinction of Lever Press Response
23
Fixed Variable RatioInterval
24
Schedules of Reinforcement Post-reinforcement pause FI scallop time # responses
25
Size of post-reinforcement pause determined by response-reinforcement ratio
26
PREE
27
What can be an operant? Practically any behavior or behavioral parameter! rate of response time of response variability of response pushes and pulls posture study habits athletic performance arts and crafts creativity bad habits and behavioral disorders
28
Allen et al. (1964) The case of Ann, a nursery school student Problems: asocial behavior, complaining, weird habits. Solution: Stop paying attention to her when she does these things.
29
Extinction of temper tantrums
30
Reinforcement without awareness Conditioning in amesics – eyeblink in HM “Memento” Radio static study Subjects told it was an experiment on stress. Twitching of very small thumb muscle actually terminated the aversive stimulus (harsh noise) Students condition professor
31
Pigeon in a Pelican
32
Ginger
33
Does anyone know how google works? google
34
Marian Breland Bailey – How to train a chicken
35
The famous dancing chicken
36
Limits on Operant Conditioning Instinctive drift – “misbehavior.” Belongingness effects – reinforcer/behavior specificity e.g., behavior systems effects. Unintended consequences –Doing one thing precludes doing other things. Some responses cannot be conditioned. –E.g., yawning or sneezing.
37
Factors that affect O.C. The response –Maze running vs. lever pressing –Running vs. throwing football Temporal contiguity
38
Delayed reinforcement
39
Overcoming the effects of delay Secondary reinforcers “Marking” procedure
41
Factors that affect O.C. The response –Maze running vs. lever pressing –Running vs. throwing football Temporal contiguity Contingency
42
“Superstitious Behavior” Suggested that temporal contiguity more important than contingency 15-s FT, no response requirement “adventitious reinforcement” “In 6 out of 8 cases the resulting responses were so clearly defined that two observers could agree perfectly in counting instances. One bird was conditioned to turn counter-clockwise about the cage, making 2 or 3 turns between reinforcements. Another repeatedly thrust its head into one of the upper corners of the cage….”
43
Orienting toward feeder Pecking near feeder Moving along wall ¼ turn
44
G.V. Thomas (1981) Contiguity pitted against contingency “Free” reinforcers given every 20s Lever press advances delivery of pellet, but cancels pellet for next 20-s interval So if you press at second 2, you get a pellet immediately, but you get no pellet during seconds 3-20 and 21-40. 20s40s60s
45
G.V. Thomas (1981) Contiguity pitted against contingency So if you press at second 2, you get a pellet immediately, but you get no pellet during seconds 3-20 and 21-40. 20s40s60s Lever press here Lose this pellet
46
Degraded Contingency Effect = bar press = food Perfect contingency Degraded contingency Signal extra food = light CS Response Strong Weak
47
Factors that affect O.C. The response –Maze running vs. lever pressing –Running vs. throwing football Temporal contiguity Contingency The reinforcer –Magnitude, quality –Upshifts and downshifts
48
Anticipatory Contrast - Crespi (1942) Rats run down maze to find food pellets in goal arm.
49
Reinforcement of Variability
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.