Tuesday, 15 March 2011

They Shape Horses, Don't They?

For many horse owners, this only happens in an ideal world.

Every so often, behaviour analysis is able to take an important problem, operationalise it in objective terms, and implement a reinforcement procedure that yields spectacular results. This is one of those occasions.

Charlotte Slater, a former masters student, and I have just had published a two-study article that investigated the use of differential positive conditioned reinforcement for reducing undesirable behaviour and increasing desirable behaviour in horses. It was based on a previous study by Ferguson and Rosales-Ruiz (2001). In our study, the horses were all referred to as "problem loaders" - they resisted being loaded into trailers and were often subject to aversive methods, such as shouting, clapping, tightening of ropes around the rear quarters, and whipping. In addition, one horse had been struck from behind with a large plastic tube during previous loading attempts. Not surprisingly, the horses' owners were desperate for a non-aversive solution to their problem, and one that they could continue to implement, once the intervention had ended.

The first stage involved conducting a task analysis - a detailed breakdown of the sequence of steps involved in fully loading (obtained by watching a horse that could fully load). Clicker training was then conducted, in which the sound of the clicker was paired with food until the horse could 'associate' the sound with a nice, tasty treat (Polo mint, anyone?). This meant that we could use the clicker as a conditioned reinforcer, and save us a fortune on Polo mints! It also allowed us to deliver reinforcement immediately and contingently following the behaviours we were interested in shaping up. Gradually, approximations of the goal behaviour (fully loading) were reinforced, bit by bit, starting with touching a target, which was moved closer and closer to the inside of the trailer.

We used a multiple baseline across horses design to illustrate the effects of the shaping procedure. All four horses showed immediate improvements when the intervention was introduced and all readily loaded, without protest or complaint, on several consecutive days. As if this wasn't impressive enough, all horses showed that they would now fully load when their owners conducted the intervention and when a novel trailer was used. Once learned, these shaped behaviours showed generalization, an important training target for a study like this as horses are often required to load into unfamiliar trailers by unfamiliar handlers.

A further study was conducted with one of the horses that had never had shoes fitted because of the problematic behaviour he showed every time his feet were handled. The target behaviour for this study was to have the horse allow his feet to be held for 1 minute. At the outset, he would not allow his feet to be held for more than 5 seconds, but during the intervention, we reinforced progressively longer periods of feet-handling (in steps of 10s). After 20 sessions, the horse met the training criterion: he allowed his feet to be handled for 1 minute, across consecutive sessions. His problem behaviour decreased, and it was now possible to have shoes fitted for the first time.

The horses owners rated the intervention highly and all considered the program to be completed either “quickly” or “very quickly”. Each owner felt able to continue using the techniques and reported that they would be “very likely’ to use the techniques to train other horses and would “definitely” recommend the procedure.

These encouraging findings show that is possible to overcome seemingly intractable problem behaviour without recourse to aversive treatment by shaping desirable behaviour. They also illustrate the wide range of challenges that are amenable to "the power of positive reinforcement".

Reference (PDF from the link below):

Slater, C., & Dymond, S. (2011). Improving equine welfare: Using differential reinforcement to shape appropriate equine behaviour during truck loading and feet handling. Behavioural Processes, 86, 329-339.

See also:

Ferguson, D. L., & Rosales-Ruiz, J. (2001). Loading the problem loader: The effects of target training and shaping on trailer- loading behavior of horses. Journal of Applied Behavior Analysis, 34, 409-424.