Training Science Articles:
Make sure to read the article on Stimulus Stacking as well.
There are four basic ways of helping our horses overcome fear. Our goal is not to remove or teach them to ignore their instinct to defend themselves (through the freeze-flight-fight responses), nor to teach them to tolerate every stimuli in the world, but rather to help them build a sense of self confidence and encourage curiosity.
1) Flooding: This is an extremely common method in the horse world. The learner is presented with a prolonged (normally high) level of the fearful stimulus in a situation where escape is limited or not available at all (a round pen for example). The stimulus remains until the fear response is gone.
Advantages: This is an extremely fast method, one session can stop the fear response to that stimuli, multiple sessions can stop a fear response for many things.
Disadvantages: This puts the learner through a great deal of stress, they are extremely overthreshold (and learning can not occur over threshold). They have not learned not to fear the stimuli or become more confident, all they've learned is that there is no escape from the fearful stimuli and their freeze-flight-fight response is ineffective. Many times these fear-responses will return when the learner is no longer contained or when there is a “Stimulus Stack”.
Advantages: This is extremely effective and causes very low or almost no stress in the learner.
As a Clicker Trainer I try to keep my horses' stress to a minimum and work hard never to let them go over-threshold (if I have any control over the situation). My goal is not to teach my horses to hide their feelings or prevent them from expressing themselves like a real horse. Rather, I want to build their confidence and inspire curiosity. I do this by mixing these methods, while I avoid flooding whenever possible, I like to make regular use of all the rest.
When time is not important I like to provide novel stimuli, silly things that could be loved or hated by my horses, provided in a corner of their field for them to explore in their own time. I may have it provide some sort of food reward, but only something moderate-low value, like hay and only while ample food is available, to prevent conflict. They will, over time, habituate themselves to these. I like to vary these up, I have swimming pools, tarps, bottles, buckets, noise makers (like wind chimes or stereos playing low level sounds), anything you can think of.
When there is something I need my horses to be comfortable with sooner rather than later I generally start with systematic desensitization, starting with the lowest possible expression of the stimuli and slowly increasing as the horse becomes comfortable. When the horse is comfortable with the stimuli (close to neutral) I will then begin to counter condition it. I wait until the stimuli is nearly neutral to reduce conflict and reduce hiding emotions. I don't want to give rewards for “looking calm”, when they aren't actually feeling calm, as that would have similar results to punishing fear responses. I like to finish off my desensitizing with counter confitioning, so I can be sure there are no longer aversive feelings in the stimulus and it won't become a part of a stimulus stack.