Module 27: Operant Conditioning

operant conditioning

a type of learning in which a behavior becomes more likely to recur if followed by a reinforcer or less likely to recur if followed by a punisher.

law of effect

Thorndike’s principle that behaviors followed by favorable consequences become more likely, and that behaviors followed by unfavorable consequences become less likely.

operant chamber

in operant conditioning research, a chamber (also known as a Skinner box) containing a bar or key that an animal can manipulate to obtain a food or water reinforcer; attached devices record the animal’s rate of bar pressing or key pecking.

reinforcement

in operant conditioning, any event that strengthens the behavior it follows

shaping

an operant conditioning procedure in which reinforcers guide behavior toward closer and closer approximations of the desired behavior.

discriminative stimulus

in operant conditioning, a stimulus that elicits a response after association with reinforcement (in contrast to related stimuli not associated with reinforcement).

positive reinforcement

increasing behaviors by presenting positive reinforcers. A positive reinforcer is any stimulus that, when presented after a response, strengthens the response.

negative reinforcement

increasing behaviors by stopping or reducing aversive stimuli. A negative reinforcer is any stimulus that, when removed after a response, strengthens the response. (Note: Negative reinforcement is not punishment.)

primary reinforcer

an innately reinforcing stimulus, such as one that satisfies a biological need.

second (conditioned) reinforcer

a stimulus that gains its reinforcing power through its association with a primary reinforcer; also known as a secondary reinforcer.

immediate vs delayed reinforcement

immediate is reward sooner with little thinking vs delayed is thinking through decisions and waiting

reinforcement schedule

a pattern that defines how often a desired response will be reinforced.

continuous reinforcement schedule

reinforcing the desired response every time it occurs.

partial (intermittent) reinforcement schedule

reinforcing a response only part of the time; results in slower acquisition of a response but much greater resistance to extinction than does continuous reinforcement.

fixed-ratio schedule

in operant conditioning, a reinforcement schedule that reinforces a response only after a specified number of responses.

variable-ratio schedule

in operant conditioning, a reinforcement schedule that reinforces a response after an unpredictable number of responses.

fixed-interval schedule

in operant conditioning, a reinforcement schedule that reinforces a response only after a specified time has elapsed.

variable-interval schedule

in operant conditioning, a reinforcement schedule that reinforces a response at unpredictable time intervals.

punishment

an event that tends to decrease the behavior that it follows.

positive puishment

an example of operant conditioning where a behavior is discouraged with the application of a negative stimulus or experience. A classic example of this is observed when a child is spanked for acting out inappropriately.

negative punishment

removes a aversive stimulus; the desired consequence (freedom from pain), increases the likelihood that the behavior will be repeated