Final answer:
In operant conditioning, extinction happens when a behavior that was once reinforced is no longer reinforced, leading to a decrease in that behavior's frequency.
Step-by-step explanation:
In operant conditioning, extinction occurs when a behavior that has been previously reinforced no longer receives reinforcement and consequently decreases in frequency. This can be seen in different reinforcement schedules. For instance, in a fixed interval schedule, like when medication is dosed hourly and reinforcement does not occur when expected, extinction can occur swiftly.
In contrast, with a variable ratio schedule, extinction tends to occur more slowly, as the behavior has been reinforced at unpredictable intervals, making it more resistant to extinction. Operant conditioning, a theory established by B.F. Skinner, involves modifying behavior through consequences like reinforcement or punishment, which either strengthens or weakens the behavior.