The Bridge

So this summer is probably the first time I have been consistently using a "bridge" in my training. Backing up a little (Mommy this is for you!) -- a "bridge" or bridging stimulus or marker is something used in animal training to note when an animal is doing the correct behavior and you want to "mark" it, and then give the animal its reward. A popularized use of this technique is called "clicker training", where the bridge/marker is the distinct clicking sound that a clicker makes when you press and release the thin metal or plastic tongue.
You can learn more about the world of Karen Pryor Clicker Training here: http://www.clickertraining.com/

I've been doing a lot of thinking about when and why use a bridge. It's interesting the seemingly ambiguous rules people come up with in terms of when to use the bridge and when it's not necessary. It's also educational to mingle with people on both extremes in terms of bridge use -- the ones who never ever use a bridge, and the ones who will always, no matter what, use a bridge before they reward an animal.

So...in what circumstances is a bridging stimulus going to enhance your training, when is it going to do basically nothing, and when is it going to hinder you? These questions are actually (I think) really important and all too often ignored -- or never posed.

We've had this discussion at work a couple times before. I guess work has never come up in this blog before -- this is where I work/learn/get inspired/everything : http://drsophiayin.com/

There are a couple different scenarios where a bridge is beneficial:

1. The behavior you are trying to get is very exact (e.g. getting a dog to perk its ears up - or just one ear? Who's up for the challenge...)
2. The behavior you are trying to get is at some distance away from you - basically there is some physical block between when/where the behavior occurs and your ability to present the reward at that time/location (e.g. having a cat turn it's head away from you)
3. The bridge is buying you time before your animal goes over threshold. This is the case where you want to reward a behavior (e.g. Benji not exploding when he sees a kitty running across the room), but if you just hand the animal the reward, it is likely that they will have gone over threshold by the time the food gets to them.
• I think that this last one is the reason why we so often feel the need to use the bridge when working with the mustangs here at Mustang Camp. It is such an enhancing tool (and not just a trainer habit).

And when is a bridging stimulus useless?

You've already started giving the reward. I actually catch myself doing this all the time. I'm saying "Yes!" as I deliver the food. What is Benji tuned in to? Most likely the hand coming at his face.

Finally, and maybe most importantly, when does the bridge hinder your training?

I actually had to think about this for quite a while. This is what I've come up with - and maybe it's not the right answer, maybe it's not the most complete answer, but it's a start. And a start at discussing the notion that maybe we don't always want to use a bridge.

1. I'm so concerned with accidentally bridging an incorrect behavior that I have accidentally lost any behavioral momentum and my animal is no longer interested in trying to earn reinforcement.
2. I am positioning my reward so that my animal continues along the same trajectory it is getting rewarded for. For example, I want my zebra to go station on a mat and I want to reward him for taking steps towards it, should I bridge and then reward (and run the risk of my zebra stopping and looking at me for a reward), or should I just present the food along the trajectory my zebra is taking to his mat in a way that he keeps moving toward it?
3. Along the same lines as #2, the final scenario I could come up with where a bridge would hinder my training is when I don't want my behavior to end. I want my animal to continue performing the behavior, and I will give sequential rewards to maintain this behavior. Technically, a bridging stimulus marks the end of a behavior. Naturally then (or so it seems), wouldn't I want to avoid using a bridge for a behavior I don't want my animal to stop performing? (e.g. asking a horse to turn its head -- and keep it there!)

On another note, I was also thinking about the term "dog trainer" versus "animal trainer". Really, what "dog trainer" in the general sense implies is somebody who trains everyday pet owners on how to train their dogs. "Animal trainer" on the other hand brings to mind a person (the trainer), working directly with an animal to teach it some behavior. Somehow, these are two very different things -- and it's interesting to think about how different types of people with the same or similar educational backgrounds/hands-on training experience would be more attracted to one or the other.

Headed to Bloomfield tomorrow to check out and help process the new mustangs we will be getting. Guess I should get to bed!!