Final answer:
The reinforcement schedule described is a differential reinforcement of other responding schedule (DRO), where reinforcement occurs only when a specific behavior is not performed for a set time period.
Step-by-step explanation:
The situation described in the question matches a differential reinforcement of other responding schedule (DRO). This reinforcement schedule specifically reinforces a subject for not performing a certain behavior over a set period. If the behavior occurs during this interval, the clock resets, and the subject must wait another full period before it can receive reinforcement. In this case, the rat is reinforced for not pressing the lever for a period of one minute, which teaches the rat to press the lever less frequently.