Most horses are trained about 1 to 2 hours daily. This means that a horse spends most of the day in its stable, paddock, pasture or other housing. Therefore, how the horse is kept has a big impact on its well-being. Of course you want to avoid stress here for better well-being, but did you know that this can also have an effect on how well the horse performs during training? How housing stress affects a horse's ability to learn is one of the components of the research by Evans et al.
Adapting to circumstances
Horses are generally good at learning new behaviors, by linking cause and result: the horse puts his nose in your pocket and receives a treat.
But many horses face more challenges. A different rider, training method or new insight from the trainer can cause the same instruction to now suddenly call for a different response from the horse.
For example, the horse's new owner is stricter and putting his nose against the pocket does not result in a treat anymore. The horse now has to learn that moving his head away from the jacket results in a reward.
Switching to a new response to a given stimulus requires a lot of flexibility from a horse. How well horses can handle such a change varies from horse to horse.
The effect of arousal on learning ability
Studies in other animal species (and in humans) suggest that a certain amount of energy, excitement, is necessary for effective learning. We are talking about excitement in the form of enthusiasm or stress. You may recognize this: if you sit half asleep at a lecture, you probably don't remember much of it.
On the other hand, too much excitement also reduces your ability to learn. This can come from too much stress or anxiety, but also from too much positive arousal. For example, you sometimes see this when training with very tasty food rewards: the horse gets so excited that it can no longer pay attention and learn well. In order to learn well, it is therefore important to achieve just the right level of excitement in the horse.
This effect of arousal during training has been studied many times. What is less known is to what extent the horse's basic arousal plays a role. Can the level of excitement the horse experiences in housing or during daily management cause it to learn better or worse, by definition, during training?
The study
To investigate this, Evans et al. looked at 22 horses. All horses remained in their normal housing, received unlimited roughage, and were allowed to walk freely outside and socialize with other horses on a regular basis.
After the horses were taught the principle of clickertraining, the study could begin. The horses first learned to distinguish between two targets: a black and a white sign. One of the two signified a food reward. If the horse touched it, the click sounded and the horse received the reward. It is worth noting that during all the experiments, the horses had the choice to walk away.
If the horse knew this well enough and chose the right sign in at least 80% of the cases, the next phase of the study began: reversing the learning process. Now, the other sign meant a reward. If before the horse received a food reward if he touched the black sign, now he received it if he touched the white sign.
Logically, the horses first touched the sign that they had previously learned yielded a reward. The researchers looked at how long it took a horse to realize that the meaning of the signs had now been reversed and again touched the correct sign 80% of the time.
With all the data they got from these experiments, the researchers were able to calculate for each horse how well that horse could learn.
Measuring heart rate variability
Of course, they then also wanted to know if excitement outside of training affected how well the horse did in the exercises. To do this, they measured the heart rate variability of the horses at rest (when the horses were stabled) and during training.
Looking at heart rate, you can measure how often the heart beats per minute. For adult horses, this is somewhere between 28 and 40 times per second. But these beats are not neatly distributed throughout the minute. If a heart beats 60 times per minute, it does not mean that there is always a second in between. Sometimes this will be slightly longer and sometimes slightly shorter. This time between heartbeats (the interval) is called the heart rate variability.
Heart rate variability is influenced by several factors, including stress. A higher heart rate variability is generally associated with lower arousal (stress). A lower heart rate variability (the beats come in quicker succession) can be an indicator of stress.
Relaxed horses can learn better
The researchers clearly saw that horses that had higher heart rate variability during the day (and thus had less excitement, or were calmer) performed better in the exercises.
In other words, a relaxed horse can learn better.
This is an important insight. If a horse is stressed during the day due to improper housing or other stressors (not enough roughage, not enough social contact, no free exercise, etc.), chances are that that horse is also less able to learn. So this has a direct impact on your training.
For good learning ability, it is therefore essential to ensure that a horse experiences as little stress as possible, even when you are not training him.
Next level: the role of hormones and the brain
Learning new things sometimes seems so obvious to us, but it involves a lot of complicated physical processes.
Dopamine (also known as the happiness hormone) is a neurotransmitter that plays an important role in the learning process. It makes us feel pleasant. This means that we want to keep repeating things that cause dopamine to be released. This can be food, but also exercise, sex or the use of certain drugs.
Dopamine can be released roughly in two ways in the brain: continuously/on the background (tonic release) or temporarily/in pulses (phasic release). The tonic release of dopamine causes an individual to seek rewards and thus be motivated to learn. The moment such a situation with a reward occurs, the phasic release also comes into action. Initially, that dopamine is released at the moment the horse receives the reward, but later it can also move forward, when the horse is awaiting the reward.
Example: a horse gets a reward when he touches a target, which is accompanied by dopamine release. After a while, the horse gets extra dopamine the moment he sees the target alone.
If the horse then expects a reward but does not get it, the whole dopamine system must reset. In this process of "reverse learning," the phasic release of dopamine plays an important role.
Previous studies suggest that the blinking frequency of a horse's eye is linked to this dopamine system. This would mean that by looking at a horse's blink frequency, we could say something about how well that horse is able to learn. Louise Evans talks more about this in her webinar (see bottom of this blog).
The temperature of a horse's eyes could also be a predictor of a horse's ability to learn by telling something about brain activity.
A horse's brain, like that of humans, is divided into two parts: the left and right hemispheres. The left hemisphere plays a dominant role when it comes to learning. Whereas the right hemisphere is often more involved in observing the entire environment and keeping an eye out for potential danger, the left hemisphere becomes more active when it comes to responding to a specific trigger.
In this study, the researchers saw that in the horses that performed the exercise best, the temperature of the left eye increased. This could be because in these horses, the left hemisphere became more active. As a result, more blood flows to that half and thus to the left eye.
Science into practice
This research shows the importance of proper housing and management for the horse's performance in training. So check for yourself whether the horse's basic needs are met, you can think of:
does the horse get enough roughage?
does the horse have the opportunity for free social contact with other horses, going beyond just seeing each other?
does the horse have sufficient opportunity for free exercise?
does the horse have sufficient challenge to stimulate curiosity?
is a dry and safe place available for sleeping?
If you have the opportunity, it may also be interesting to put a heart rate monitor (which also measures variability) on the horse outside of training. Give the horse about half an hour to get used to the meter before you start reading the results. What do you see in the heart rate variability? How high or low is it in different situations with your horse?
This is also interesting to watch when you are training. Does the variability go down sharply? Then there is a good chance that the horse is experiencing too much excitement and thus cannot learn well at that moment.
LIVE WEBINAR WITH LOUISE EVANS
Would you like to hear all the details of this study and other studies linked to it from Louise Evans herself? And would you like to know why the researchers were always monitoring the horses' blinking frequency? Then join the live webinar on Thursday, Feb. 15!
Source: Louise Evans, Heather Cameron-Whytock, Carrie Ijichi, Eye understand: Physiological measures as novel predictors of adaptive learning in horses, Applied Animal Behaviour Science, Volume 271, 2024, 106152, ISSN 0168-1591
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