Behaviorism.ppt

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1、Behaviorism,B. F. Skinner,B.F. Skinner (1904-1990),B. F. Skinner (1904-1990)Skinners life and his understanding of life Predetermined, lawful, and orderly A product of past reinforcements 1925: Hamilton College (NY): degree in English, no courses in psychology Read about Pavlovs and Watsons experime

2、ntal work 1931: Ph.D. from Harvard,B. F. SkinnerDissertation: a reflex is a correlation between S and R 1938: The Behavior of Organisms 1953: Science and Human Behavior 1990: Vigorously attacked the growth of cognitivepsychology 1990 (final article): “Can Psychology Be a Science of Mind?“,B. F. Skin

3、nerDealt only with observable behavior The task of scientific inquiry: To establish functional relationships between experimenter-controlled stimulus and organisms responseNo presumptions about internal entities - The “empty organism“ approach,B. F. SkinnerSingle subject design Large numbers of subj

4、ects not necessary Statistical comparisons of group means not necessary A single subject provides valid and replicable results Requires “sufficient“ data collected under well-controlled experimental conditions Statistics obscure individual responses and differences,Pavlovs dog,Classical conditioning

5、 Watson, Pavlov - Respondent behavior: elicited by specific observable stimulus,http:/ Rat,B. F. SkinnerOperant behavior: occurs without an observable external stimulus Operates on the organisms environment The behavior is instrumental in securing a stimulus more representative of everyday learning,

6、http:/ F. SkinnerScience of behavior: Study of conditioning and extinction of operants Dependent variable in the “Skinner box“: rate of response Law of acquisition key variable: reinforcement practice provides opportunities for additional reinforcement,http:/ Guided Missile,The US Navy required a we

7、apon effective against the German battleships. The size of the primitive guidance systems available rendered any weapon ineffective.Pigeon was potentially an extremely simple and effective solutionThe project centered around dividing the nose cone of a missile into three compartments, and encasing a

8、 pigeon in each. The compartments for each had a video image of what was in front of them, and the pigeons would peck toward the object, thereby directing the missile. Skinner:“our problem was no one would take us seriously.“ Few people would trust a pigeon to guide a missile no matter how reliable

9、it proved.,Skinners Theory,“All we need to know in order to describe and explain behavior is this: actions followed by good outcomes are likely to recur , and actions followed by bad outcomes are less likely to recur.” (Skinner, 1953),Central Human Motive in Skinners Theory,Environmental consequence

10、s shape behavior,LAW OF EFFECT,Behavior Better state Increased of affairs probability of behavior occurring again Behavior Worse state Decreased of affairs probability of behavior occurring again Behavior A Behavior B Behavior C Better state Behavior C Behavior D of affairs emerges as the Behavior E

11、 most probable,OPERANT CONDITIONING TECHNIQUES,POSITIVE REINFORCEMENT = increasing a behavior by administering a reward NEGATIVE REINFORCEMENT = increasing a behavior by removing an aversive stimulus when a behavior occurs PUNISHMENT = decreasing a behavior by administering an aversive stimulus foll

12、owing a behavior OR by removing a positive stimulus EXTINCTION = decreasing a behavior by not rewarding it,B. F. SkinnerResearch foci Role of punishment in response acquisition Schedules of reinforcement Extinction of operants Secondary reinforcement GeneralizationSubjects included humans as well as

13、 animals,B. F. SkinnerSchedules of reinforcement Reinforcement is necessary in operant behavior Reinforcement schedules continuous fixed and variable ratio and interval,SCHEDULES OF REINFORCEMENT,Interval schedules: reinforcement occurs after a certain amount of time has passed Fixed Interval = rein

14、forcement is presented after a fixed amount of time Variable Interval = reinforcement is delivered on a random/variable time scheduleRatio schedules: reinforcement occurs after a certain number of responses Fixed Ratio = reinforcement presented after a fixed # of responses Variable Ratio = reinforce

15、ment delivery is variable but based on an overall average # of responses,LIMITED EFFECTS OF PUNISHMENT,Punishment does not teach appropriate behaviors Must be delivered immediately & consistently May result in negative side effects Undesirable behaviors may be learned through modeling (aggression) M

16、ay create negative emotions (anxiety & fear),B. F. SkinnerCriticisms of Skinners behaviorism His extreme positivism His opposition to theory His willingness to extrapolate beyond the data The narrow range of behavior studied Problem of instinctive drift His position on verbal behavior,B. F. SkinnerContributions of Skinners behaviorism Shaped American psychology for 30 years His goal: the improvement of society Stength and ramifications of his radical behaviorism,http:/