Lateralized emotional functioning in domestic animals

The study of emotional functioning is of crucial importance for improving the welfare of domestic animals. The investigation of animal emotions is mainly based on the outcomes of affective states, specifically animal behaviour, physiology and cognition. The cognitive component of emotions includes the processes regulating the affective states in animals, which are lateralized in the animal kingdom. Functional asymmetries in emotional processing, indeed, have been widely reported in both vertebrates and invertebrates. To date, the study of animal emotions through the evaluation of cerebral lateralization has been mainly performed through the analysis of lateralized behaviours, which indirectly reflect the prevalent activation of the right or the left hemisphere. In particular, the asymmetric processing of different environmental stimuli through the different senses as well as the lateralized motor patterns have been associated with different aspects of animal emotions. In this review, we present a comprehensive overview of the behavioural asymmetries for the sensory and motor functions related to emotional functioning of domestic animals. Our final aim is to support the use of laterality as a tool to evaluate animal emotional processing, and therefore, their welfare.