The question of animal emotions

If the UK joins a handful of other nations to recognize the sentience of invertebrates, such as cephalopod mollusks and decapod crustaceans, by, for example, prohibiting the boiling of live lobsters, this will be based on evidence that emotions and felt experiences (i.e., sentience) are not limited to animals close to humans, such as the mammals. This topic has been heavily debated in both affective neuroscience (how to define an emotion?) and philosophy (what is the moral relevance of animal experiences?), but a consensus on the criteria for and implications of recognizing animal sentience seems to be emerging (1).