In today’s horse world, it is common for horse owners to treat horses how ad campaigns, breed associations, or boarding barn friends might suggest they care for their horses. “You didn’t clip your horse’s whiskers before the show?” Or, “I can’t believe you keep your horse in the pasture with other horses! Aren’t you worried about injuries?” How about, “Winter coats are so ugly. Blanket from September through March to keep off the Winter Woolies!”
While none of the above comments are meant to harm horses, they reflect a “human-centric approach to horse care. If our horses could reply, we’d hear, “Don’t clip my whiskers; they help me where my vision lacks. I need to be out in the pasture with my herd for my health, and I don’t need any fancy clothes—I grow my own winter wardrobe.”
Our horses can’t talk, but we can turn to science to find out what’s best for them. Using even simple scientific knowledge about horses will help in both management and training. For example, do you know how smell affects horses, or how the forebrain and hind-brain integrate and work? Do you know how horses learn, or how sensitive the nose is to stimuli? Do you know how many neurons to pro-preceptors there are reaching the hind end? If you are serious about training or just love horses, then read on. A number of scientists and trainers are coming together to explore what we know about the horse’s biology, neurology, and psychology.
The exchange of this knowledge can help us better understand the horse’s needs, as well as applying it to training groups like The International Society for Equitation Science www.equitationscience.com. And the interest in behavioral research at many universities has caused a wave within the horse industry, bringing trainers and scientists together. That’s why well-known horseman and clinician Martin Black has paired up with Dr. Stephen Peters, a neuropsychologist who specializes in brain functioning, to digest information about the horse’s brain and natural anatomy. Their book and accompanying DVD, Evidence-Based Horsemanship, pairs science with empirical insight to recommend best practices for horse owners.
Though Evidence-Based Horsemanship delves deeply into equine brain anatomy, neurochemistry, and the nervous system, people can see just by looking at the horse’s brain how similar, and just how strikingly different, horses and humans are.
The horse’s brain is about the size of a large grapefruit and is proportionately 1/650th of its body weight. In comparison, the human brain is about 1/50th of our body weight. Current research still supports that the brain ratio to body mass reflects a level of cognitive skills, thus giving humans more capacity to think. However, this doesn’t mean the horse is dumb; it simply thinks and processes slightly different than humans, relying more on instinct and group decisions than individual thought.
The growing equine brain
When the horse’s brain first develops and begins to mature, brainstem pathways form first. They involve many automatic behaviors. Motor patterns of this immature brain are mostly under the brainstem’s control.
As prey animals, horses must be born much more “ready for life” than humans—they’re able to stand and move just after birth. A fatty substance in the brain called myelin acts as an insulator and coats nerve fibers to help the transfer of information, which allows for rapid brain growth and maturation. (Good myelination is also what helps information transfer between the two sides of the brain through the corpus callosum.)
Because the motor and locomotion pathways are the most critical to the foal’s survival, they are the first to become fully myelinated, so that the foal can move with its herd and stay out of the path of predators. At this point, no real thinking is involved. More advanced brain center connections have not yet been developed.
The next key area to mature and develop connections is the cerebellum. The nerve development of this pathway allows for the coordination and smoothing out of the horse’s movement. The reason for such herky-jerky movement in foals is because the cerebellum and its connections are not fully developed.
One of the most important structures of the horse’s brain, the cerebellum plays a role in controlling balance, head, and eye movements. For the rest of the horse’s life, the cerebellum will act as a library for storing all learning regarding physical movement.
The Horse Brain versus the Human Brain
Size-wise, the cerebellum accounts for about a third of the horse’s brain. And, because the horse is a motor/sensory animal, the horse is all but ruled by the cerebellum. Humans, on the other hand, are ruled by the frontal lobe. You could interpret this as humans being more of a “thinking” species, while horses are more of a “sensory and feeling” species.
When we compare the human brain to that of other animals, we see that brain cells, brain molecules, neurotransmitters, and synapses are almost identical in all animals. At this level, animals are made from the same essential building blocks. When discussing brain function, it’s helpful to first consider the human brain since we can only think from a “human-centric” perspective.
We can think of the brain as having three progressive layers with various functions. The layers have distinct functions, but their interactions are essential and considerable.
The reptilian brain (consisting of the brain stem and cerebellum) is concerned with survival and body maintenance. Digestion, reproduction, circulation, breathing, and the ‘flight or fight’ response are all reptilian brain functions.
The second layer is the limbic system. It includes the amygdala and hippocampus and involves emotion and memory. The limbic system concerns itself with primitive activities related to food, sex, and bonding. It is responsible for memories of behaviors connected to agreeable and disagreeable experiences. In humans, these are called emotions.
The third layer is the neocortex or cerebral cortex. It makes up most of the human brain. Language, speech, and writing are all possible because of this layer. It’s also where we perform abstract thinking, organize things, categorize ideas, reason and multi-task. The large human neocortex versus the underdeveloped version of the equine is one of the most notable differences between the way humans and horses operate.
We owe it to ourselves to take an objective look at our horses for what they are, as well as how they are so very different from us. In doing so, we’ll not only better understand our equine companions but also improve our horsemanship and horse care.
Horses and humans share similarities as social mammals. Our brains allow us both to have emotions, sensory experiences, and autonomic physiological functions. The human brain, however, has a much larger, developed cerebral cortex, allowing greater capacity to think, use deductive reasoning and become self aware. Horses on the other “hoof,” are great at reacting to stimuli, sensing their environment, and relaying on their friends to make decisions—they would rather “feel” than “think.” Horse brains, however, have a well-developed brain stem and limbic system. As an experiment, try to think and feel “like a horse.” Spend a day “being your horse” and see how it changes your view. Can you become more “horse-centric?” Let us know!