Heather Browning

This paper addresses what we consider to be the most pressing challenge for the emerging science of consciousness: the measurement problem of consciousness. That is, by what methods can we determine the presence of and properties of consciousness? Most methods are currently developed through evaluation of the presence of consciousness in humans and here we argue that there are particular problems in application of these methods to nonhuman cases - what we call the indicator validity problem and the extrapolation problem. The first is a problem with the application of indicators developed using the differences in conscious and unconscious processing in humans to the identification of other conscious vs. non-conscious organisms or systems. The second is a problem in extrapolating any indicators developed in humans or other organisms to artificial systems. However, while pressing ethical concerns add urgency in the attribution of consciousness and its attendant moral status to non-human animals and intelligent machines, we cannot wait for certainty and we advocate the use of a precautionary principle to avoid doing unintentional harm. We also intend that the considerations and limitations discussed in this paper can be used to further analyse and refine the methods of consciousness science with the hope that one day we may be able to solve the measurement problem of consciousness.

Animal welfare has a long history of disregard. While in recent decades the study of animal welfare has become a scientific discipline of its own, the difficulty of measuring animal welfare can still be vastly underestimated. There are three primary theories, or perspectives, on animal welfare - biological functioning, natural living and affective state. These come with their own diverse methods of measurement, each providing a limited perspective on an aspect of welfare. This paper describes a perspectival pluralist account of animal welfare, in which all three theoretical perspectives and their multiple measures are necessary to understand this complex phenomenon and provide a full picture of animal welfare. This in turn will offer us a better understanding of perspectivism and pluralism itself.

There are many decision contexts in which we require accurate information on animal welfare, in ethics, management, and policy. Unfortunately, many of the methods currently used for estimating animal welfare in these contexts are subjective and unreliable, and thus unlikely to be accurate. In this paper, I look at how we might apply principled methods from animal welfare science to arrive at more accurate scores, which will then help us in making the best decisions for animals. I construct and apply a framework of desiderata for welfare measures, to assess the best of the currently available methods and argue that a combined use of both a whole-animal measure and a combination measurement framework for assessing welfare will give us the most accurate answers to guide our action.

One of the most challenging questions surrounding subjective animal welfare is whether these states are measurable: that is, is subjective welfare an appropriately quantifiable target for scientific enquiry and ethical and deliberative calculation? The availability of several different types of measurement scale raises important questions regarding whether subjective experience has the right properties to be meaningfully represented on the types of scale required for different applications. This methodological question has so far received scant attention in the animal welfare literature. In this paper, I address this omission by examining the types of measurement scale we can reasonably expect to apply to animal welfare measurements, and which we will actually need for our applications. I argue that our different applications will require variously ordinal, interval, and ratio scales, and that we have sufficient reason to believe that subjective welfare is a target with the appropriate characteristics to justify the practice of representing it using each of these types of scales.

One of the primary concerns in animal research is ensuring the welfare of laboratory animals. Modern views on animal welfare emphasize the role of animal sentience, i.e. the capacity to experience subjective states such as pleasure or suffering, as a central component of welfare. The increasing official recognition of animal sentience has had large effects on laboratory animal research. The Cambridge Declaration on Consciousness (Low et al., University of Cambridge, 2012) marked an official scientific recognition of the presence of sentience in mammals, birds, and cephalopods. Animal sentience has furthermore been recognized in legislation in the European Union, UK, New Zealand and parts of Australia, with discussions underway in other parts of the world to follow suit. In this paper, we analyze this shift towards recognition of sentience in the regulation and practice in the treatment of laboratory animals and its effects on animal welfare and use.

There is increasing recognition that the welfare needs of cephalopod molluscs and decapod crustaceans are important. Current commercial practices involving these animals include a range of potential threats to their welfare, such as conditions of farming, capture, transport, and slaughter. This article draws from and updates our 2021 review for the UK Government, recommending a range of relatively simple and impactful changes that could benefit welfare while highlighting important research gaps that should be prioritised to facilitate the drafting of guidelines for best-practice.

With increasing attention given to wild animal welfare and ethics, it has become common to depict animals in the wild as existing in a state dominated by suffering. This assumption is now taken on board by many and frames much of the current discussion; but needs a more critical assessment, both theoretically and empirically. In this paper, we challenge the primary lines of evidence employed in support of wild animal suffering, to provide an alternative picture in which wild animals may often have lives that are far more positive than is commonly assumed. Nevertheless, while it is useful to have an alternative model to challenge unexamined assumptions, our real emphasis in this paper is the need for the development of effective methods for applying animal welfare science in the wild, including new means of data collection, the ability to determine the extent and scope of welfare challenges and opportunities, and their effects on welfare. Until such methods are developed, discussions of wild animal welfare cannot go beyond trading of intuitions, which as we show here can just as easily go in either direction.

While global aquaculture is rapidly expanding, there remains little attention given to the assessment of animal welfare within aquacultural systems. It is crucial that animal welfare concerns are central in the development and implementation of aquaculture as if they are not prioritized early on, it becomes much more difficult to adapt in future. To this end, it is important to ensure the availability of high-quality welfare assessment schemes to evaluate the welfare of animals in aquaculture and promote and maintain high welfare standards. This paper will first discuss some of the current certification and assessment frameworks, highlighting the primary limitations that need to be addressed, before going on to describe the recommendations for a best-practice welfare assessment process for aquaculture; with the hope that these considerations can be taken on board and used to help improve welfare assessment for aquaculture and, ultimately, to ensure animals used in aquaculture have a higher level of welfare. Any aquacultural system should be assessed according to a suitable framework in order to be considered adequate for the welfare of the animals it contains, and thus to maintain social license to operate.

One of the biggest problems in applications of animal welfare science is our ability to make comparisons between different individuals, both within and across species. Although welfare science provides methods for measuring the welfare of individual animals, there’s no established method for comparing measures between individuals. In this paper I diagnose this problem as one of underdetermination—there are multiple conclusions given the data, arising from two sources of variation that we cannot distinguish: variation in the underlying target variable (welfare experience) and in the relationship of measured indicators to the target. I then describe some of the possible methods of making comparisons, based on the use of similarity assumptions that will have greater or lesser justification in different circumstances, and the alternative methods we may use when direct comparisons are not possible. In the end, all our available options for making welfare comparisons are imperfect, and we need to make explicit context-specific decisions about which will be best for the task at hand while acknowledging their potential limitations. Future developments in our understanding of the biology of sentience will help strengthen our methods of making comparisons.

‘Sentience’ sometimes refers to the capacity for any type of subjective experience, and sometimes to the capacity to have subjective experiences with a positive or negative valence, such as pain or pleasure. We review recent controversies regarding sentience in fish and invertebrates and consider the deep methodological challenge posed by these cases. We then present two ways of responding to the challenge. In a policy-making context, precautionary thinking can help us treat animals appropriately despite continuing uncertainty about their sentience. In a scientific context, we can draw inspiration from the science of human consciousness to disentangle conscious and unconscious perception (especially vision) in animals. Developing better ways to disentangle conscious and unconscious affect is a key priority for future research.

Measurement of subjective animal welfare creates a special problem in validating the measurement indicators used. Validation is required to ensure indicators are measuring the intended target state, and not some other object. While indicators can usually be validated by looking for correlation between target and indicator under controlled manipulations, this is not possible when the target state is not directly accessible. In this article, I outline a four-step approach using the concept of robustness that can help with validating indicators of subjective animal welfare.

Animal welfare has a long history of disregard. While in recent decades the study of animal welfare has become a scientific discipline of its own, the difficulty of measuring animal welfare can still be vastly underestimated. There are three primary theories, or perspectives, on animal welfare - biological functioning, natural living and affective state. These come with their own diverse methods of measurement, each providing a limited perspective on an aspect of welfare. This paper describes a perspectival pluralist account of animal welfare, in which all three theoretical perspectives and their multiple measures are necessary to understand this complex phenomenon and provide a full picture of animal welfare. This in turn will offer us a better understanding of perspectivism and pluralism itself.

Beyond simple consciousness or sentience, some non-human animals may possess more sophisticated cognitive abilities linked to capacities for self-awareness or even personhood, capacities that may influence our attitudes toward the importance of their suffering. In this chapter, we first examine the concepts of consciousness, suffering, self-awareness, and personhood before surveying the current evidence for these capacities in different animal species and discussing their relevance to the moral importance of animal suffering. We argue that while self-awareness is not necessary for morally relevant suffering, it may serve to expand the range of ways in which an individual can suffer (including increasing the harm of death), as well as potentially grounding a higher level of moral status.

Recent discussions in animal welfare have emphasised the importance of animal agency—the ability of animals to make choices and exert control over their environment in a way that aligns with their needs and preferences. In this paper, we discuss the importance of animal agency for welfare and examine how use of some types of animal–computer interaction can enable animals to exercise more agency in captive environments through increased choice and control, cognitive challenge, and social interactions; as well as considering some of the potential limitations of such efforts.

The study of introspection has, up until now, been predominantly human-centric, with regrettably little attention devoted to the question of whether introspection might exist in non-humans, such as animals and artificial intelligence (AI), and what distinct forms it might take. In their target article, Kammerer and Frankish (this issue) aim to address this oversight by offering a non-anthropocentric framework for understanding introspection that could be used to address these questions. However, their discussions on introspection in animals and AIs were quite brief. In this commentary, we will build on their suggestions to offer some methodological guidance for how future research into introspection in animals and AIs might proceed.