The influence of experimental neurosis on the conditional reflexes and the content of blood catecholamines and acetylcholine in dogs.

Using experimental neurosis as a model, we investigated the mode of adaptive behavior, conditional reflexes and the blood level of neuromediators in four dogs placed in certain versus uncertain conditions in a Pavlovian laboratory. The research consisted of a two year training program with predictable (ordered partial reinforcement) followed by unpredictable (probabilistic reinforcement) situations. As a result, there was a decline in the acetylcholine as compared to a rise of catecholamine levels of the peripheral blood of some of these dogs. There were varied autonomic responses indicating a possible individual response specificity. In one dog, there was a disappearance of motor defense reflexes. The results support the hypothesis that probabilistic reinforcement following ordered partial reinforcement contributed to the dogs' neurotic disintegration, i.e., uncertainty is a cause of neurotic development.