Higher-Order Conditioning in Dogs

A researcher is conducting an experiment to investigate the process of classical conditioning using a group of dogs. In the initial phase, the researcher repeatedly pairs the sound of a metronome (neutral stimulus) with the presentation of food (unconditioned stimulus) to the dogs. Over several trials, the dogs start to salivate (conditioned response) upon hearing the metronome, even in the absence of food.

After establishing this conditioned response, the researcher begins to introduce a new stimulus: a light that is turned on at the same time as the metronome. This light is presented without any food. Following multiple pairings of the light with the metronome, the researcher allows the dogs to see the light without the metronome or food. What phenomenon is the researcher most likely observing with regard to the dogs’ response to the light?