Spontaneous attention-capture by auditory distractors as predictor of distractibility: a study of domestic horses (Equus caballus).

Distractibility (i.e. individual distraction from his ongoing activity) is thoughts to affect daily life. The present study develops an easy way to assess inter-individual variations of distractibility of an animal model, the domestic horse. We developed the 'distractibility test' (DT), based on auditory stimuli, a major source of distraction in daily life. We hypothesized that the broadcast of unusual sounds would provide a reliable source of distraction and that the responses to these unusual sounds would yield a good estimation of a horse's level of distractibility. Validity of the DT was assessed by comparing the subjects' interest towards the sound in this test to their attentional state in experimental visual attention tasks and in a working task. Our results showed inter-individual differences in response to the stimuli, with consistency over time. The subjects' responses to this DT were negatively correlated to their attentional skills in separate experimental tests and in a working task. This is to our knowledge the first 'real-world' estimate of an animal's distractibility in its home environment that could potentially be adapted for humans.