Notes from "Pavlov's Wednesdays": Gestalt relationships as conditioned stimuli.

When A.O. Dolin's dog Ger was trained to differentiate between metronomic frequencies of 60 (positive) and 120 (negative) per minute, its conditioned salivary reaction to the positive stimulus was attenuated immediately after a test on a more positive stimulus (30 per minute) and that to the negative stimulus was augmented immediately after a test on a more negative stimulus (200 per minute). Pavlov and his colleagues considered explanations based on the relationship between the test and trained stimuli, on reciprocal induction, and on gradients of generalized excitation and inhibition à la Spence. This was just before Pavlov's death, but his last words on the topic leaned in the Gestalt relational direction.