The Influence of Negative Incentive on Mice Learning Curve

Topic: Would higher electric shock will cause mice to learn faster how to to go through a maze.
Researchers: Robert Yerkes and John Dodson
Published At: Journal of Comparative Neurology and Psychology
Year: 1908
Formal Reference: Robert Yerkes and John Dodson, "The Relation of Strength of Stimulus to Rapidity of Habit-Formation", Journal of Comparative Neurology and Psychology 18 (1908), Pages 459-482,
Main Conclusion: Negative incentive can stimulate mice learning up to a point, from which learning performance is deteriorating as incentive increases.

Description of Experiment
a. Mice were placed in a maze, where the walls are colored Black & White (or Red &. Blue, or with spots, and other combinations) and each such pattern came with electric shock if the mice goes into the wrong direction. Mice were expected to learn that going into the white corridors, for example, is the right path while entering a Black corridor will trigger an electric shock.
b. Researchers measured the mice's learning curve as a function of the volume of the electric shock
c. The results showed that in the beginning the increase of the electric shock led to better learning curve, but from a certain point onwards the increase of the electric shock resulted in deteriorating learning performance.

When negative incentives are introduced, they work up to a certain level; at some point stronger incentive leads to weaker performance.