If horses entrain, don’t entirely reject vocal learning: An experience-based vocal learning hypothesis

Abstract

Bregman and colleagues describe methods for testing whether horses entrain their actions to an auditory beat. If horses can entrain, does this necessarily imply that there is no causal relationship between vocal learning and entrainment? I propose an alternative way in which vocal learning may relate to entrainment – one that is consistent with entrainment in some vocal non-learning species. Due to engaging in the developmental process of vocal learning, there may be early experiences common to vocal learners, but rare in vocal non-learning species. It is possible that it is these experiences that are critical for entrainment – not vocal learning itself, nor related genes. These experiences may result in critical changes in neural development, leading to the development of cognitive mechanisms necessary for both vocal learning and entrainment. This hypothesis changes the causal story from one of genetic change to one of changes in experience, and from a focus on evolution to a focus on individual ontogeny. Thus, if horses can entrain, we should not immediately reject the idea of a relationship between vocal learning and entrainment: First, we should consider whether some unusual aspect of the horses’ experience effectively replicates the unusual experiences of vocal learning animals.