Higher Order Conditioning
Higher Order Conditioning (also known as Second Order Conditioning) is a classical conditioning term that refers to a situation in which a stimulus that was previously neutral (e.g., a light) is paired with a conditioned stimulus (e.g., a tone that has been conditioning with food to produce salivating) to produce the same conditioned response as the conditioned stimulus. Wow...if you understand how a neutral stimulus becomes a conditioned stimulus (conditioning), you understand higher order conditioning because this is really just extending the conditioning one more level...the conditioning is happening not by pairing the stimulus with something that naturally produces a response, but with something that has been conditioned to produce a response.