Horse Brain, Human Brain. Janet Jones
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academic meetings, I used to focus my eye just to the side of where a trying colleague was seated. Then with imperceptible movements, it was possible to move the person’s face into and out of my blind spot for some private entertainment. You can learn to do the same. Stand far enough back at a horse show, and you can even make a naughty pony disappear.
More importantly for our purposes, your horse has a roaming blind spot large enough that an object can disappear at the right distance. This object could be a bird, dog, or small child, for example. If we step silently out of a horse’s blind spot, or even if we remain stationary but the horse moves, we might startle him. Sudden discoveries make horses nervous—no prey animal wants predators popping in and out of sight, or demanding frontal views and preventing escape, all while the brain says, “Run!”
Groundwork
Most trainers use groundwork when starting young horses under saddle. Groundwork refers to any form of training in which the horse is not being ridden. We use it to teach leading, longeing, ground manners, and respect for human space. But we often forget that it’s useful in adult years as well, to teach a horse to back, spin, jump, or move laterally, for example. And it’s an excellent technique to revert to when problems arise.
The key is to realize that it’s a lot harder for horses to relax and learn while we’re sitting on them. So, step off and give them a better chance. Don’t worry, you’ll get back on again before the lesson is over. Remain quiet and calm, moving the horse with your eyes, hands, body position, voice, lead, reins, and/or a whip used only as an extension of your arm to touch the horse’s hindquarters. Groundwork does not require chasing a frightened horse in tight circles with flapping plastic bags tied to a stick. This is more properly called “frightwork,” in my opinion, and it usually causes more harm than good. Good groundwork takes skill and practice. Take the time to learn it well, and it will help your team.
Chapter Four
Training with Vision
We’ve seen that equine acuity and focus are poor, but peripheral range and motion detection are excellent. Let’s round out our understanding with a few added aspects of equine eyesight: night vision, depth perception, visual capture, and color vision.
By nature, equestrians ride on the basis of human assumptions, imagining—if we ponder it at all—that the horse visualizes depth and color the same way we do. We also assume that other equine senses are subordinate to vision, as ours are. Because of misinformation concerning night vision and our own inexperience with it, we presume that horses see details in the dark with superhero sensitivity. The reality is quite different. Doubling down on these discrepancies between human and equine sight explains many common problems within the horse-and-human team.
Night Vision
Horses can see in the dark, right? So they have no trouble jumping at dusk or loading onto the trailer before dawn? Well, not so much! Take a look at your horse’s pupil sometime. See how much longer and larger it is than a human pupil? Large horizontal pupils take in more light across a wider range of visual angle. Having entered the eye, this luminosity filters toward the back of the eye, shining onto that patch of rods and cones that changes particles of light into neural impulses. Those impulses are then routed to areas of the brain that interpret their meaning.
Horses also have iridescent collagen fibers in an upper area of the eyeball called the tapetum (“TAP-uh-tum”). These fibers reflect light from the ground into the eyeball, allowing the horse to gather small amounts of illumination while moving in darkness. Human eyes have a similar mechanism, the choroid coat, but it is not as large or strong as the tapetum and cannot reflect light to an equivalent degree. In both species, the collagen fibers become visible when reflected in a camera flash or headlight. Ours appear to be red, but in horses, the eye-shine varies among green, yellow, or blue depending on a horse’s coat color and age.
With large pupils and a reflective tapetum, horses have a reasonable degree of night vision—enough to wander from hay bin to water trough in the dark and notice movements in the shrubs. It’s more acute than human night vision, which is about as effective as underwater breathing, but still not sharp enough to identify details, hop a cross-rail, or load into a trailer comfortably. The fact that a horse will try to complete these tasks in the dark is evidence of a willingness to obey, not proof of good nocturnal eyesight.
Dark Adaptation
The real rub with night vision comes when we realize that horses can make out shapes in dark conditions only after a long period of pupillary adaptation. This makes sense because equine vision developed when horses stood outside as dusk settled very slowly on the earth. But today, we expect them to enter dark barns and indoor arenas from bright sunlight.
Show riders often expect horses to move from sunlight into an indoor arena during performance. Top facilities use intense lights for illumination, but lesser locations tend to skimp. And at home, most winter riders work horses indoors, where footing is good but lighting is not. How do these changes affect equine performance?
Although all disciplines are affected, let’s consider jumping because it is so dependent on acute equine eyesight. Jumping horses have to judge the height and width of fences very quickly, often scanning distances on a short approach, adjusting stride length for takeoff, carrying riders who transmit countless cues, and coordinating their bodies to clear obstacles by only an inch or two. These are meticulous feats that would cause many human athletes to stumble.
Riders all over the world warm up hunters and jumpers in bright sun prior to competition. After a typical warm up, Twinkletoes’ pupils are constricted to the maximum degree to admit as little light as possible. The chemicals that transduce light into neural impulses are at their ebb. This combination of pupillary contraction and chemical paucity allows the horse to jump in bright sun without being blinded by the glare. High elevation, central latitudes, low humidity, pale arena sand, and white fences demand even greater adaptation.
Twinkletoes is jumping well in the warm-up when the gate steward calls him to the indoor show arena. His rider removes her sunglasses at the in-gate, instantly improving her indoor vision. Too bad Twink can’t shove his face into some military night goggles. Through the gate they go, galloping into the murk to leap over 8 or 12, sometimes 15, jumps that the horse can barely see. And oh, by the way, like all of us, Twink’s rider expects top-quality performance. But he hasn’t come close to the 45 minutes he needs to accommodate to indoor lighting. Typically, he’s had one minute, if that.
The scenario described here is common. We allow it because we are not aware of the visual hardship for the horse. Most of us reprove mounts who balk at the in-gate, weave between fences, skirt the flower box, or refuse to jump. We assume that if we can see the course, they can, too. But imagine moving from a sunny parking lot into a darkened movie theater, then dashing around under a heavy backpack—hurdling seats, slipping on buttered popcorn, and dodging angry patrons. The fact that horses try to perform under such circumstances is a testament to their generosity.
Like humans, horses differ in individual visual abilities. One horse might require a little less than 45 minutes to adapt to dim light; another will require even more. Age plays a role, too. Older horses with healthy eyes take in less light than younger horses do. This age difference occurs in humans as well—in fact, the average person’s eyes take in 66% less light at age 60 than at age 20. No wonder the world can seem a little glum as we get older.
How can we help our horse’s eyes adapt before performing? No suggestion is ideal, but some will help. Allow your horse to walk in the shade before entering an indoor arena. Stand at the gate for a few minutes while the preceding team competes. When possible, schedule a jumping performance right after a flat class, giving your horse 15 minutes of adaptation time prior to starting over fences. Remember that a jumping round, no matter how easy it looks, is a complicated and unnatural coup for a horse. He can’t just phone it in.
The best solution is to require show organizers and facilities managers to brighten indoor arenas with strong artificial lighting. Exhibitors, trainers, boarders, and owners have the power to make such requests as a group, especially when safety is at stake. Veterinary schools and organizations can help the cause by publicizing the need for strong