International audienceThe emotional valence of a situation can modulate selective attention. The valence of training experience is crucial for horses, the use of a positive reinforcement as a food reward has been shown to enhance learning performances and to promote a positive relation to the trainer. Here, we investigated the impact of different reinforcement (no reinforcement, primary positive reinforcement) or action (scratch the wither) on the horses’ attentional state in a learning task. In a first study, 15 young males Angloarabian were trained to remain still in response to a vocal command. Immobility was rewarded either with a piece of food (n=8) or with no reward (n=7). In a second study, 15 young polish horses (6 females, 9 males)...