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BF Skinner. American Behaviorist Operant conditioning “Skinner Box”. Skinner. Operant chamber permits precise control of stimuli typical behavior is a key peck or bar press Behavior units small, measurable, behaviors. FREE-OPERANT PROCEDURES
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BF Skinner • American Behaviorist • Operant conditioning • “Skinner Box”
Skinner • Operant chamber • permits precise control of stimuli • typical behavior is a key peck or bar press • Behavior units • small, measurable, behaviors
FREE-OPERANT PROCEDURES • responses made by the animal at a pace which they set • (i.e., they are “free” to operate on their environment by responding whenever they would like and however often they would like). • Skinner eliminated the maze altogether • designed a chamber with start box and the goal box in the same place so the animal didn't have to run anywhere DISCRETE TRIALS PROCEDURES = during training, 1) each trial ends when you remove the animal from the apparatus 2) the instrumental response is performed only once during each trial. Usually, discrete trial procedures use some type of maze.
Skinner • Magazine Training • preliminary phase of conditioning • pairing food delivery devise with food • Shaping • sequence of training
steps in training: 1ST STEP = MAGAZINE TRAINING = sound of being delivered: teach the rat to associate the "click" produced by the feeding mechanism with the delivery of food (classical conditioning) 2ND STEP = SHAPING = rewarding successive approximations to the desired behavior (operant conditioning)
Differential Reinforcement Successive Approximations(MSA) • Shaping: A technique for training responses that are initially unlikely to occur. The first step is to reinforce whatever aspect of an individual’s behavior is closest to the desired response. As this behavior begins to occur more often, the trainer withholds reinforcement until some closer approximation to the desired response occurs, and so on • Lieberman (2001)
Lever Shaping • Begin differential reinforcement of behaviors that most resemble, or could lead to, the desired behavior (lever pressing) • These behaviors are known as successive approximations because they gradually approximate the desired behavior
RESPONSE-OUTCOME CONTINGENCIES Some definitions: APPETITIVE STIMULUS = A pleasant event. AVERSIVE STIMULUS = An unpleasant event. POSITIVE CONTINGENCY = a response "turns on" a stimulus = a rat can press the bar which will activate the food magazine and he will get some food. NEGATIVE CONTINGENCY = a response "turns off" a stimulus = a rat can be sitting in the Skinner box and the experimenter can deliver a loud noise – if the rat presses the bar the noise will be turned off.