A pigeon is trained with two separate S^D stimuli, a tone and a yellow light. Assume that a green light serves as an S^Δ and acquires an extraordinary amount of inhibition, such that it will generalize very widely across the spectrum. What should happen to peak shift around the S^D? A) Nothing. B) It should be shifted very far toward red. C) It will be reduced (i.e., the spread of inhibition will go past the S^D, making the excitatory gradient around the S^D very narrow). D) It will actually reverse the peak shift, moving it to wavelengths below green.

Question

Quizplus · Accepted Answer

The peak shift phenomenon occurs when discrimination training leads to a preference for stimuli that are even further from the non-reinforced stimulus (in this case, the green light) than the reinforced stimulus (the yellow light). Given the green light acquires a significant amount of inhibition and generalizes widely, the peak of preference should shift away from green, towards the opposite end of the spectrum, which is towards red. This is because the presence of inhibition around the green light makes stimuli that are further away from green (and closer to red) more attractive, as they are less inhibited and thus more associated with reinforcement.

A Pigeon Is Trained with Two Separate SD Stimuli, a Tone

A Pigeon Is Trained with Two Separate S^D Stimuli, a Tone