The "Feeder Hand" in Action

This photo illustrates the use of a food-dispensing fake hand during the beginning stages of behavior modification to change the dog's attitude towards approaching strangers.
This particular dog has in the past had several instances of lunging aggressively towards approaching strangers and had also done so towards one of his two owners. This has appeared to be a case of a dog who is "jealous-possessive" , showing "object guarding" of people to whom he is bonded towards approaching people, either strangers or other family members.
While this particular dog's problem was primarily aggressive behavior, a similar protocol is used to change attitude of a dog whose problem is fearfulness towards an approaching stranger.
The rehabilitation protocol , "desensitization with counter-conditioning", being tried, of which the very first lesson is here shown, is to have strangers approach the muzzled and leashed dog, but not closely enough to trigger an aggressive lunge or any signs of fear or aggression and certainly not so close as to put themselves in danger, and while the dog is still calm the stranger offers a food treat from the artificial hand, thus tending to counter any potential aggressive emotions by instead eliciting the pleasurable emotions associated with yummy food.
Initially the hand was moved very slowly and from a low direction. Later the hand was moved more quickly and at times coming from above the dog's head (which some dogs consider to be more threatening or more dominating). Also later the hand might stroke the dog's head or touch the person the dog is being held by. The goal is always to have the hand's action be mild enough that the dog does not feel aggression.
Please notice that the dog is wearing a vet type of muzzle and a halter over it, and there is a second leash on the dog's flat collar. Both leashes are held so there is a modest amount of slack in the leashes (so that tension does not cause the dog to feel anxious or aggressive) , but the handler is well prepared to intercept any attempted lunge. In this picture the dog is standing, but for most of the approaches the dog was told to sit or to lie down ; when lying down, there was slack in the leash but the handler's foot was on the leash , again to ensure control.
We initially tried using a wire basket muzzle (with the halter underneath the muzzle), as it offers the helpers the maximum of safety; but we found that the dog was having too much difficulty taking the food treat into his mouth. So we switched to the veterinary muzzle, the open front end of which allows food to be taken easily. This is not quite as safe for the helper, but this helper is an experienced dog person and was carefully instructed and guided through the procedures.
On this occassion, the very first session with this dog and the very first trial of two different types of food-dispensing hand, we had a very good result with both of two dog-smart helpers. We were able to include touching the dog with the hand and touching the handler, myself (whom on a previous occassion the dog had attempted to "object guard" by aggressive lunging). The dog's attitude remained unaggressive throughout the series of approaches, and his attitude remained happy interest in getting food rather than fear or aggression.
Based on this good first session, there is reason to hope that a very careful and lengthy course of desensitization and counter-conditioning could be successful in changing the dog's attitude to become one of cheerfully welcoming approach of strangers, strangers touching the dog, and strangers touching the dog's handler.