Measuring animal welfare: What can cognition contribute?

In this review, we explore a variety of techniques that are currently available to investigate the welfare of non-human animals (referred to from now on as animals) with a particular focus on studies of animal cognition. We consider some of the more traditional measures of animal welfare: biological function, physiology and inference, and discuss different ways in which we might assess welfare requirements. We then consider whether cognitive assays can help us determine what animals want or prefer, and whether it is possible to use cognition to discover the mental or affective state of an animal (i.e. positive or negative affective states). We defend that certain aspects of cognition will play a fruitful role in helping us to understand animal 'mental welfare' and, in this way, we make a case for how cognition can be usefully applied in a welfare context.