Animal consciousness: new knowledge

The issue of consciousness in both humans and animals is both a societal debate and a vast research topic. In 2009, at the request of the Ministries for Agriculture and Research, INRA compiled a scientific expert report on pain in animals which defined pain as a two-dimensional issue: the sensation of pain (nociception) and consciousness that interprets this sensation and enables an individual to react. This initial expert report formed part of an action plan resulting from meetings on animals and society held in 2008. The relationships between humans and animals have long formed part of the research topics and organisation of INRA, with a European dimension resulting from the coordination of European research programmes, and the Animal Health and Welfare ERA-Net (ANIHWA). More than 80 INRA scientists operate a multidisciplinary network in France on animal welfare called “Agri Bien-être animal” (AgriBEA) which combines research, development and training. In 2015, the Joint INRA-CIRAD Ethics Advisory Committee worked on the welfare of farmed livestock and formulated recommendations that were taken up by the Institute. Benefiting from these measures and the expertise of its scientists, INRA was able to address the issue of animal consciousness at the request of the EFSA by mobilising 17 experts, seven of them from other research institutions. The expert report on animal consciousness has thus informed and updated knowledge in a broader area than that which could be addressed by the expert report on animal pain.

Animal consciousness has been a research topic for philosophers since antiquity. In the 19th century, naturalists and later comparative psychologists and ethologists further questioned the mental states of animals. They came to the conclusion that consciousness does occur in animals. Research on biological and psychological issues resulted more recently in several major conceptual innovations which established that consciousness is the outcome of brain processes. And indeed, since January 2015, the French Civil Code has recognised animals as “sentient beings”.

A multidisciplinary research topic

Subjected to cognitive tests, animals have behaviour which shows their capacity to experience emotions, their ability to seek information when lack of knowledge has been detected and also to process past and future. The study of the social behaviour of animals and human-animal relationships indicate the existence of different forms of consciousness with variable degrees of complexity. As for humans, animal consciousness might be best described as the emerging product of interactions between different functional layers constituted by perceptual, attentional, mnesic, emotional and evaluative competences.

Current studies explore the neural correlates of consciousness in animals. Some levels of consciousness in animals have already been acknowledged, notably by considering sleep/awakeness as a modulator of the level of consciousness. Upon the perception of a stimulus of interest, several of these layers are activated and interact to ultimately produce interpretations and intentionality which are externalized through the expression of conscious actions. Thus, processes related to consciousness allow the emergence of responses which have greater complexity and content than the simple combination or addition of individual responses of separate systems.

Depending on the animal species or external factors considered, consciousness may fluctuate. The question, in that context, is whether the cognitive abilities engendering consciousness are the result of evolutionary processes. They could also be the result of convergence in evolution which has occurred in species not related phylogenetically, thus having different neuronal structures, but facing equal environmental constrains. Although a clear demonstration of an evolutionary role for consciousness is still lacking.

Animal pain and sentience

Current knowledge suggests that at least vertebrates are equipped with nervous systems that support conscious processes of complex information, including negative emotions caused by nociceptive stimuli.

While sentience may be widespread among animals, more elaborate contents of consciousness have only been documented across a small range of species, among primates, corvidae, rodents and ruminants. Such higher contents need in particular autobiographic memory, including episodic memory. Because animals with autobiographic memory, as observed in primates, corvidae and rodents, can have desires and goals that extend into the past and the future, they can be negatively affected by aversive experience.

Future research

This multidisciplinary expert report analysing a vast corpus of behavioural, cognitive and neurobiological findings tends to demonstrate the existence of elaborate contents of consciousness in the species studied until now. It was also able to identify new research needs. In particular, it would be desirable to broaden current fields of investigation to a larger range of animal species, to develop experimental systems that can better distinguish conscious behaviours from acquired automatisms and to better understand the mental functioning of farmed livestock.

Because research in the field of animal consciousness has up until now been focused on a small number of species of mammals and birds, it would be desirable to fill these gaps by widening the field of investigation to a larger range of animal species. To improve our understanding of the mechanisms of their mental functioning, experimental protocols will strive to distinguish between those behavioural and physiological answers of animals that stem from conscious behaviour from those associated with acquired automatisms which can be complex. The study of the development of the forms of consciousness at a young age is particularly important for farm animals, which have generally a brief life. The way they represent themselves and their world and how they relate to their environment would enrich our thinking on how to improve their welfare and the way they are handled. The nature of the relationships of animals with the humans who raise them should also be studied in domesticated species.

Full report published by EFSA on the Wiley platform