Instrumental/Operant Conditioning

Thorndike’s Puzzle Box

Result

Thorndike’s Law of Effect “Of several responses made to the same situation, those which are accompanied or closely followed by satisfaction…will be more likely to recur” SituationResponseOutcome Puzzle BoxPull LoopMeat or Fish S  R association

Two Theories Thorndike –Stimulus associated with response (S-R), so the response is a “habit” triggered by the situation Grandmother –“Cat is working to get food” (R-O) SituationResponseOutcome Puzzle BoxPull LoopMeat or Fish R  O association

Test of Grandma’s Theory Stage 1: Train instrumental S-R-O Stage 2: Alter value of O (devalue) in the absence of R and S Stage 3: Test to determine if R is reduced

Responding

Shaping Shaping is a method for encouraging novel behavior –Reinforcing successive approximations to the target behavior

Types of Reinforcers Primary Reinforcers satisfy a need and reinforces behavior without any special experiences Secondary Reinforcers become valuable through association with primary reinforcers

Delay of Reinforcement Delayed reinforcers are steeply discounted Loss of self-control and implusivity Precommitment Reinforcer Potency Delay

Stimulus Discrimination

Stimulus Discrimination?

Positive and Negative Reinforcement

Shuttle Box Escape versus Avoidance Conditioning

Schedules of Reinforcement Continuous Reinforcement Schedule: Reinforcer is delivered every time a particular response occurs. Partial or Intermittent Reinforcement Schedule: Reinforcement is given only some of the time.

Partial Reinforcement Schedules Fixed Ratio (FR): Reinforcement occurs after a fixed number of responses. Variable Ratio (VR): Reinforcement occurs after a varied number of response. Fixed Interval (FI): Reinforcement occurs for the first response after a fixed time interval Variable Interval (VI): Reinforcement occurs for the first response after a variable time interval

Partial Reinforcement Schedules

Schedules and Extinction Failure to reinforce a response eventually extinguishes it. Partial reinforced responses are more difficult to distinguish. –“Partial reinforcement extinction effect” –“Superstitious behavior” is resistant to extinction for this reason

Why Reinforcers Work Deprived of the opportunity to engage in behavior (drink, eat, etc.), called the response deprivation hypothesis Physiological –James Olds and “pleasure centres” –Nucleus Accumbens and Dopamine

Punishment and Learning Punishers decrease of probability the immediately preceding response –Two kinds of punishment.Two kinds of punishment. Negative Reinforcement versus Punishment –Negative Reinforcement: Strengthens behavior –Punishment: Weakens behavior Continue

Figure 5.11: Two Kinds of Punishment Return

Drawbacks of Punishment Only suppresses unwanted behavior Unwanted side effects –target becomes aggressive, avoidance Often ineffective unless a strong punisher given immediately after every response (e.g., red light camera) Does not specify what should be done.

Guidelines for Effective Punishment Specify why punishment is being given Emphasize the behavior, not the person, being punished Without being abusive, make sure the punishment immediate and noticeable Identify and positively reinforce more appropriate responses.

Some Applications of Instrumental Conditioning Classroom Management Token Economies in Mentally Challenged Autism Self-Control

Other Specialized Forms of Learning Spatial Learning Knowledge Attribution Helplessness Observational Learning –Mirror neurons