How did Skinner apply the concept of negative reinforcement?

Skinner's application of negative reinforcement involved using electric shocks that the rat could turn off by performing a certain behavior, such as pressing a lever. Negative reinforcement is a concept in operant conditioning where a behavior is strengthened by the removal of an aversive stimulus. In this case, the electric shock serves as the aversive stimulus. When the rat learns to press the lever to stop the shock, it is more likely to repeat this behavior in the future, reinforcing the connection between the action and the relief from discomfort. This demonstrates Skinner's principle of negative reinforcement effectively, illustrating how behavior can be influenced by the consequences of actions.

The other options do not accurately represent negative reinforcement. Rewarding a rat with food pertains to positive reinforcement, where a desirable stimulus is added to increase a behavior. Introducing other animals does not relate to the reinforcement concept at all, as it does not provide a context for behavior modification. Removing obstacles from the environment does not involve consequences that strengthen or weaken behavior directly, distinguishing it further from the concept of reinforcement in Skinner's experimental framework.