Stress modulates instrumental learning performances in horses (Equus caballus) in interaction with temperament.
Authors: Valenchon Mathilde, Lévy Frédéric, Prunier Armelle, Moussu Chantal, Calandreau Ludovic, Lansade Léa
Journal: PloS one
Summary
# Editorial Summary When horses acquire new skills under acute stress, their initial performance may actually improve—yet this apparent benefit comes at a cost to long-term retention. Researchers assessed the temperament of horses before exposing them to a stressor either before or after an instrumental learning task, then evaluated their reacquisition of the same task eight days later without stress present. Horses stressed after learning showed significantly impaired reacquisition performance compared to unstressed controls, whilst those stressed during acquisition showed a smaller but similar effect, suggesting that stress-induced memory associations with the learning environment undermined consolidation. Temperament traits markedly influenced learning only under stressful conditions: horses with higher locomotor activity performed better when stressed, whilst fearful horses showed substantially worse performance, indicating that reactive individuals are more cognitively vulnerable during handling or training when environmental stressors are present. For practitioners, this highlights the importance of minimising acute stress during and immediately after skill acquisition—particularly when working with naturally fearful or reactive animals—as stress may appear to sharpen focus initially but compromises the long-term retention essential for reliable performance in competition or practical contexts.
Read the full abstract on PubMed
Practical Takeaways
- •Training timing matters: avoid stressful situations immediately after learning sessions, as this impairs the horse's ability to consolidate and improve upon learned tasks in subsequent sessions.
- •High-activity, low-fear horses learn better under pressure, while fearful horses benefit from calm training environments; tailor your teaching approach to individual temperament when external stressors are unavoidable.
- •A single stressful event before training may not hinder performance, but stress associated with the learning context itself can create lasting interference with future practice — minimize negative associations with training locations.
Key Findings
- •Acute stress before acquisition tended to enhance early success rates in instrumental learning tasks.
- •Horses stressed after acquisition failed to improve performance during reacquisition 8 days later, whereas non-stressed controls showed improvement.
- •Temperament traits (locomotor activity and fearfulness) only influenced learning under stressful conditions, not baseline performance.
- •State stress from memory of a prior stressor impaired reacquisition more severely than stress exposure before initial acquisition.