Studies have shown that things which are traditionally thought of as aversive (for example, electric shocks) can be set up in such a way that the introduction of an electric shock can actually increase responding - thus making it, technically, a reinforcer. To simplify the explanation, the electric shocks act as a signal or cue for future events (i.e. the presentation of food), and so they take on a conditioned value which can be used to increase behavior.
Isn't this the way of the collar use today ..? A reinforcer of a known command ...IE: dog is in route and back nick back ...Stimulation when the dog is doing a command correctly? Steve S