What reinforcement schedule provides rewards for the first response after a fixed period of time?

The fixed interval reinforcement schedule is characterized by providing rewards after a specific and consistent amount of time has passed, contingent upon the first response occurring after that time has elapsed. For example, if a behavior is reinforced after a 5-minute interval, the subject will receive a reward immediately following their first response after those 5 minutes.

This type of schedule can create a pattern where responses increase as the time for reinforcement approaches, leading to a "scalloped" response pattern. The subject learns to anticipate when the reinforcement will occur, thus influencing their behavior accordingly. In contrast to other types of reinforcement schedules, such as variable interval or continuous reinforcement, the fixed interval schedule is defined by the passage of time that must occur before reinforcement can be delivered for the first response.