Unveiling directional physiological coupling in human-horse interactions
Alejandro Luis Callara,
Chiara Scopa,
Laura Contalbrigo,
Antonio Lanatà,
Enzo Pasquale Scilingo,
Paolo Baragli,
Alberto Greco
Affiliations
Alejandro Luis Callara
Department of Information Engineering, University of Pisa, Via G. Caruso 16, Pisa, 56122 Pisa, Italy; Research Center “E. Piaggio”, Largo Lucio Lazzarino 1, Pisa, 56122 Pisa, Italy
Chiara Scopa
Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Viale delle Scienze 11/A, Parma, 43124 Parma, Italy
Laura Contalbrigo
National Reference Centre for Animal Assisted Interventions, Istituto Zooprofilattico Sperimentale delle Venezie,Viale dell’Università 10, 35020 Legnaro, Italy
Antonio Lanatà
Department of Information Engineering, University of Florence, Via di Santa Marta 3, Firenze, 50139 Firenze, Italy
Enzo Pasquale Scilingo
Department of Information Engineering, University of Pisa, Via G. Caruso 16, Pisa, 56122 Pisa, Italy; Research Center “E. Piaggio”, Largo Lucio Lazzarino 1, Pisa, 56122 Pisa, Italy
Paolo Baragli
Research Center “E. Piaggio”, Largo Lucio Lazzarino 1, Pisa, 56122 Pisa, Italy; Department of Veterinary Sciences, University of Pisa, Viale delle Piagge 2, Pisa, 56124 Pisa, Italy
Alberto Greco
Department of Information Engineering, University of Pisa, Via G. Caruso 16, Pisa, 56122 Pisa, Italy; Research Center “E. Piaggio”, Largo Lucio Lazzarino 1, Pisa, 56122 Pisa, Italy; Corresponding author
Summary: This research investigates the human-horse bond, aiming to unveil the physiological mechanisms regulating interspecies interactions. We hypothesized observing a physiological synchronization in human-horse dynamics, akin to human interactions. Through time-frequency Granger causality analysis of heart rate variability (HRV) and behavioral data, this study reveals the establishment of bidirectional synchronization in HRV between humans and horses. The coupling directionality is influenced by behavior and familiarity. In exploration scenarios led by horses, bidirectional interactions occur, particularly with familiar individuals. Conversely, during human-led activities such as grooming, physiological connectivity direction varies based on the familiarity level. In addition, the methodology allows in-depth analysis of sympathetic and parasympathetic nervous system contributions, highlighting their intricate role in the human-horse relationship. Such a physiological coupling estimate, correlated with behavioral data, provides a quantitative tool applicable across contexts and species This holds significant promise for assessing animal-assisted therapies and for applications in sports and various animal-related domains.
