Congratulations, your horse has learned a new trick! Now, start all over again–this time on the other side.

That's right; it turns out if you want your horse to learn a trick or skill correctly, you're probably going to have to teach with cues that are visible to the horse from both sides of his head. According to new equitation science research, what a horse learns on his left side isn't necessarily learned on the right, and vice-versa.

"Training has long involved a traditional bias of handling from the left," said Lucy Webb, BSc, researcher in the department of life sciences at Anglia Ruskin University in Cambridge, during the presentation of her work at the sixth International Equitation Science Conference in Uppsala, Sweden, on July 31. "However, it is commonly accepted that horses will pass an object on one side, yet react as though it is novel when it is presented on the other side."

To test a horse's ability to recognize training cues from opposite views, she and colleague Guy Norton, senior lecturer at Anglia Ruskin, taught head-movement tricks to horses with one eye covered. Within the field of vision that horses can only see with one eye, called the "monocular field," they were shown an object and were taught to nod their heads when they saw it. In the "binocular field"–the area of vision that can usually be seen by both eyes (when one is not covered–they were shown a different object and were taught to lift their heads when they saw it