In a recently completed study, an entirely new learning test suited to field conditions was developed to measure the learning capacity and motivation of horses in their own enclosures and other familiar environments.
A learning test for everyday equine life
Mira Hämäläinen, a veterinarian specialising in equine diseases with specialist vocational qualifications in animal care, investigated equine learning using a reverse learning test designed by her research group. In the test, the horse is taught to touch an object for a reward. When the horse learns the task, the setting is changed: the correct object is changed, and the horse must adapt its actions.
Most of the riding school horses involved in the study learned the task and completed the test successfully. Learning was measured by counting the number of correct responses per minute. This proved to be a sensitive and practical way of monitoring the horses’ progress.
“Our reverse learning test can be completed in a single day in the horse’s own enclosure. Traditionally, learning has been investigated through tests that take several days. Requiring only two people and simple equipment, the new test is easy to apply in practice,” Hämäläinen says.
Coping hinges on REM sleep quantity
Sleep is a central pillar of learning and memory in all animal species studied. Insufficient sleep impairs the formation of memory traces, as well as attention, motivation and flexibility when awake.
Hämäläinen’s study monitored nighttime REM sleep in 16 riding school horses for six weeks, conducting five sets of behavioural measurements of which each lasted 48 hours.
The results were clear: horses whose REM sleep lasted more than 30 minutes per night performed better in the reverse learning test than those whose REM sleep duration was shorter.
“Shorter REM sleep did not increase the number of mistakes, but had a particular effect on how long the horses worked on the task,” Hämäläinen says.
In other words, the horses were all able to complete the task, but those with less REM sleep gave up more easily.
“This suggests that REM sleep in horses is associated with motivation and perseverance,” Hämäläinen adds.
Adjusting to short sleep duration has its risks
No external signs of sleep disturbances were observed in the study, although some of the horses exhibited little REM sleep. The results nevertheless indicate that short REM sleep can affect equine performance, particularly when the task requires prolonged concentration and flexible thinking.
“While the horses were quick to learn simple tasks, the effects of short REM sleep periods started to show in longer and more demanding tasks,” Hämäläinen says.
“The findings offer a new tool for assessing the learning capacity and welfare of horses. They also emphasise the importance of sleep as part of their overall wellbeing,” says Doctoral Researcher Iina Brotherus, who studies equine sleep.
The study points out that coping in horses is not solely about training or motivation. The quality of sleep can also determine how effectively horses learn and tackle everyday challenges.
The study was conducted in collaboration with the Finnish Equine Information Centre, Tuire Kaimio and Henna-Kaisa Wigren, a researcher from the SleepWell group active in Meilahti.
Original article
Hämäläinen M.J., Brotherus I.L., Wigren H.M. et al. Effect of horse sleep behavior on performance in a field-side spatial reversal learning test. Scientific Reports (2026).