Animal Sciences Commons^™

Sentience In Decapod Crustaceans: A General Framework And Review Of The Evidence, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch

Animal Sentience

We outline a framework for evaluating scientific evidence of sentience, focusing on pain experience. It includes eight neural and cognitive-behavioural criteria, with confidence levels for each criterion reflecting the reliability and quality of the evidence. We outline the rationale for each criterion and apply our framework to a controversial sentience candidate: decapod crustaceans. We have either high or very high confidence that true crabs (infraorder Brachyura) satisfy five criteria, amounting to strong evidence of sentience. Moreover, we have high confidence that both anomuran crabs (infraorder Anomura) and astacid lobsters/crayfish (infraorder Astacidea) meet three criteria—substantial evidence of sentience. The case is, …

Pain Sentience Criteria And Their Grading, Eva Jablonka, Simona Ginsburg

Animal Sentience

On the basis of the target article by Crump and colleagues, we suggest a more parsimonious scheme for evaluating the evidence for sentience. Since some of the criteria used by Crump et al. are not independent and some are uninformative we exclude some criteria and amalgamate others. We propose that evidence of flexible learning and prioritization, in conjunction with relevant data on brain organization, is sufficient for assigning pain-sentience to an animal and we suggest a scoring scheme based on four criteria.

Defending Human Difference By Raising The Bar, Joe Gough

Animal Sentience

Chapman & Huffman (C&H) offer a theory of why we humans want to believe that we are different: to justify our cruelty to animals. This commentary offers further supporting evidence of this and examines more closely what the claim that humans are ‘different’ amounts to. It also considers some methodological issues in animal psychology closely related to C&H ‘s theory. These problems result from a common strategy for defending hypotheses about human difference.

Animal Sentience: History, Science, And Politics, Andrew N. Rowan, Joyce M. D'Silva, Ian J.H. Duncan, Nicholas Palmer

Animal Sentience

This target article has three parts. The first briefly reviews the thinking about nonhuman animals’ sentience in the Western canon: what we might know about their capacity for feeling, leading up to Bentham’s famous question “can they suffer?” The second part sketches the modern development of animal welfare science and the role that animal-sentience considerations have played therein. The third part describes the launching, by Compassion in World Farming, of efforts to incorporate animal sentience language into public policy and regulations concerning human treatment of animals.

Reduction In Activity By Noxious Chemical Stimulation Is Ameliorated By Immersion In Analgesic Drugs In Zebrafish, Javier Lopez-Luna, Qussay Al-Jubouri, Waleed Al-Nuaimy, Lynne U. Sneddon

Lynne Sneddon, PhD

Research has recently demonstrated that larval zebrafish show similar molecular responses to nociception to those of adults. Our study explored whether unprotected larval zebrafish exhibited altered behaviour after exposure to noxious chemicals and screened a range of analgesic drugs to determine their efficacy to reduce these responses. This approach aimed to validate larval zebrafish as a reliable replacement for adults as well as providing a high-throughput means of analysing behavioural responses. Zebrafish at 5 days postfertilization were exposed to known noxious stimuli: acetic acid (0.01%, 0.1% and 0.25%) and citric acid (0.1%, 1% and 5%). The behavioural response of each …

Fish Sentience Denial: Muddying The Waters, Lynne U. Sneddon, Javier Lopez-Luna, David C.C. Wolfenden, Matthew C. Leach, Ana M. Valentim, Peter J. Steenbergen, Nabila Bardine, Amanda D. Currie, Donald M. Broom, Culum Brown

Lynne Sneddon, PhD

Recent empirical studies have reported evidence that many aquatic species, including fish, cephalopods and crustaceans, have the capacity for nociception and pain, and that their welfare should be taken into consideration. Some sceptics, rejecting the precautionary principle, have denied that any study demonstrates pain or other aspects of sentience in fish. This target article discusses some of the scientific shortcomings of these critiques through a detailed analysis of a study exploring nociception and analgesia in larval zebrafish.

Anthropomorphic Denial Of Fish Pain, Lynne U. Sneddon, Matthew C. Leach

Lynne Sneddon, PhD

Key (2016) affirms that we do not know how the fish brain processes pain but denies — because fish lack a human-like cortex — that fish can feel pain. He affirms that birds, like fish, have a singly-laminated cortex and that the structure of the bird brain is quite different from that of the human brain, yet he does not deny that birds can feel pain. In this commentary we describe how Key cites studies that substantiate mammalian pain but discounts the same kind of data as evidence of fish pain. We suggest that Key's interpretations are illogical, do not …

Fish Sentience Denial: Muddying The Waters, Lynne U. Sneddon, Javier Lopez-Luna, David C.C. Wolfenden, Matthew C. Leach, Ana M. Valentim, Peter J. Steenbergen, Nabila Bardine, Amanda D. Currie, Donald M. Broom, Culum Brown

Culum Brown, PhD

Recent empirical studies have reported evidence that many aquatic species, including fish, cephalopods and crustaceans, have the capacity for nociception and pain, and that their welfare should be taken into consideration. Some sceptics, rejecting the precautionary principle, have denied that any study demonstrates pain or other aspects of sentience in fish. This target article discusses some of the scientific shortcomings of these critiques through a detailed analysis of a study exploring nociception and analgesia in larval zebrafish.

If It Looks Like A Duck: Fish Fit The Criteria For Pain Perception, Julia E. Meyers-Manor

Animal Sentience

Whereas we have denied the experience of pain to animals, including human babies, the evidence is becoming clearer that animals across a variety of species have the capacity to feel pain (Bellieni, 2012). As converging findings are collected from pain studies and the study of cognition, it is becoming harder to deny that fish are among the species that do feel pain.

Pain In Fish: Evidence From Peripheral Nociceptors To Pallial Processing, Michael L. Woodruff

Animal Sentience

The target article by Sneddon et al. (2018) presents convincing behavioral and pharmacological evidence that ray-finned fish consciously perceive noxious stimuli as painful. One objection to this interpretation of the evidence is that the fish nervous system is not complex enough to support the conscious experience of pain. Data that contradict this objection are presented in this commentary. The neuroanatomy and neurophysiology of the fish nervous system from the peripheral nerves to the pallium is able to support the sentient appreciation of pain.

Fish Sentience Denial: Muddying The Waters, Lynne U. Sneddon, Javier Lopez-Luna, David C.C. Wolfenden, Matthew C. Leach, Ana M. Valentim, Peter J. Steenbergen, Nabila Bardine, Amanda D. Currie, Donald M. Broom, Culum Brown

Animal Sentience

Recent empirical studies have reported evidence that many aquatic species, including fish, cephalopods and crustaceans, have the capacity for nociception and pain, and that their welfare should be taken into consideration. Some sceptics, rejecting the precautionary principle, have denied that any study demonstrates pain or other aspects of sentience in fish. This target article discusses some of the scientific shortcomings of these critiques through a detailed analysis of a study exploring nociception and analgesia in larval zebrafish.

On Crabs And Statistics, Jonathan Birch

Animal Sentience

I respond to commentaries by Elwood and Seth & Dienes and to a recent critique by Diggles, discussing the link between avoidance learning and sentience, the relevance of the clash between frequentist and Bayesian statistics, the risks to decapod welfare in aquaculture, and the broader concerns one may have about a “precautionary” approach to protecting invertebrates.

Denialism And Muddying The Water Or Organized Skepticism And Clarity? That Is The Question, Ben Diggles, Howard I. Browman

Animal Sentience

The research being commented on here has been criticized and defended in journals. Sneddon et al. (2018) add nothing substantive. We have nothing further to add. Readers are referred to Diggles (2018) and to Browman et al. (2018) for a detailed assessment.

Reduction In Activity By Noxious Chemical Stimulation Is Ameliorated By Immersion In Analgesic Drugs In Zebrafish, Javier Lopez-Luna, Qussay Al-Jubouri, Waleed Al-Nuaimy, Lynne U. Sneddon

Anesthesia and Analgesia Collection

Research has recently demonstrated that larval zebrafish show similar molecular responses to nociception to those of adults. Our study explored whether unprotected larval zebrafish exhibited altered behaviour after exposure to noxious chemicals and screened a range of analgesic drugs to determine their efficacy to reduce these responses. This approach aimed to validate larval zebrafish as a reliable replacement for adults as well as providing a high-throughput means of analysing behavioural responses. Zebrafish at 5 days postfertilization were exposed to known noxious stimuli: acetic acid (0.01%, 0.1% and 0.25%) and citric acid (0.1%, 1% and 5%). The behavioural response of each …

The Potential For Sentience In Fishes, Jay R. Stauffer Jr.

Animal Sentience

Balcombe’s book is filled with information on the biology, behavior, and life history of fishes. I do not agree with all his premises. I am still somewhat perplexed about the discussion of whether fish feel pain; I am not sure whether the distinction between nociception and pain makes any difference. Overall, however, his treatment of the principles of both natural and sexual selection is comprehensive and accurate, and has greatly increased my knowledge and awareness of the biology, ethology, and potential for sentience in fishes. In summary, this work has exposed me to new ideas about how to examine fishes …

The “Precautionary Principle” – A Work In Progress, Shelley Adamo

Animal Sentience

The target article by Birch illustrates the practical difficulties with the “Animal Sentience Precautionary Principle” (ASPP) while presenting potential solutions. However, the ASPP will be difficult to use without guidelines detailing how evidence of sentience should be assessed. Moreover, extrapolating conclusions found for a single species to all species within an Order is problematic. Finally, I recommend that Birch demonstrate his ASPP framework using a controversial test case to help show how it could be used in real-world situations.

Assessing Negative And Positive Evidence For Animal Pain, Robert W. Elwood

Animal Sentience

Jonathan Birch suggests that we should take one well-conducted study that produces results consistent with the idea of pain as being sufficient to invoke the animal sentience precautionary principle. Here, I consider how to balance negative and positive results from such studies using examples from my own work. I also consider which criteria of pain might provide strong inference about pain and which may prove to be weaker.

Insect Consciousness: Commitments, Conflicts And Consequences, Colin Klein, Andrew B. Barron

Animal Sentience

Our target article, “Insects have the capacity for subjective experience,” has provoked a diverse range of commentaries. In this response we have collated what we see as the major themes of the discussion. It is clear that we differ from some commentators in our commitments to what subjective experience is and what the midbrain is capable of. Here we clarify where we stand on those points and how our view differs from some other influential perspectives. The commentaries have highlighted the most lively areas of disagreement. We revisit here the debates surrounding whether the cortex is essential for any form …

Animal Welfare And Individual Characteristics: A Conversation Against Speciesism, Marc Bekoff, Lori Gruen

Marc Bekoff, PhD

It seems impossible for a human being not to have some point of view concerning nonhuman animal (hereafter animal) welfare. Many people make decisions about how humans are permitted to treat animals using speciesist criteria, basing their decisions on an individual's species membership rather than on that animal's individual characteristics. Although speciesism provides a convenient way for making difficult decisions about who should be used in different types of research, we argue that such decisions should rely on an analysis of individual characteristics and should not be based merely on species membership. We do not argue that the concept of …

Subjective Experience In Insects: Definitions And Other Difficulties, Shelley Adamo

Animal Sentience

Whether insects have the potential for subjective experiences depends on the definition of subjective experience. The definition used by Klein & Barron (2016) is an unusually liberal one and could be used to argue that some modern robots have subjective experiences. From an evolutionary perspective, the additional neurons needed to produce subjective experiences will be proportionately more expensive for insects than for mammals because of the small size of the insect brain. This greater cost could weaken selection for such traits. Minimally, it may be premature to assume that small neuronal number is unimportant in determining the capacity for consciousness.

The Minimization Of Research Animal Distress And Pain: Conclusions And Recommendations, Kathleen Conlee, Martin Stephens, Andrew N. Rowan

Martin Stephens, PhD

While the attention given to preventing, assessing, and alleviating pain in research animals has increased noticeably in recent decades, much remains to be done both in terms of implementing best practices and conducting studies to answer outstanding questions. In contrast, the attention to distress (particularly non-pain induced distress) has shown no comparable increase. There are many reasons for this discrepancy, including the conceptual untidiness of the distress concept, the paucity of pharmacological treatments for distress, and perceived lack of regulatory emphasis on distress. These are challenges that need to be addressed and overcome. This book is intended to help meet …

Resolving Animal Distress And Pain: Principles And Examples Of Good Practice In Various Fields Of Research, Alicia Karas, Matthew C. Leach, Karl A. Andrutis, Kathleen Conlee, John P. Gluck, Andrew N. Rowan, Martin L. Stephens

Martin Stephens, PhD

Pain and distress are central topics in legislation, regulations, and standards regarding the use of animals in research. However, in practice, pain has received greatly increased attention in recent years, while attention to distress has lagged far behind, especially for distress that is not induced by pain. A contributing factor is that there is less information readily available on distress, including practical information on its recognition, assessment and alleviation.

This chapter attempts to help fill that void by reversing the usual pattern and giving greater attention to distress than to pain. In addition, we also bypass the pain versus distress …

Recognition Of Distress In Animals – A Philosophical Prolegomenon, Bernard E. Rollin

Bernard Rollin, PhD

For those who continue to doubt the studiability of distress or suffering or misery in all of its forms in animals, consider the following thought experiment: If the government were to come up with a billion dollars in research funding for animal distress, would that money go a-begging? We can study these states just as we studied pain—excellent work on boredom by Franciose Wemelsfelder in a volume on laboratory animal welfare I co-edited made the methodology for such study quite explicit. (Wemelsfelder, 1990) And when the ideological scales fall from our eyes, we realize that the work of scientists like …

Fish Intelligence, Sentience And Ethics, Culum Brown

Culum Brown, PhD

Fish are one of the most highly utilised vertebrate taxa by humans; they are harvested from wild stocks as part of global fishing industries, grown under intensive aquaculture conditions, are the most common pet and are widely used for scientific research. But fish are seldom afforded the same level of compassion or welfare as warm-blooded vertebrates. Part of the problem is the large gap between people’s perception of fish intelligence and the scientific reality. This is an important issue because public perception guides government policy. The perception of an animal’s intelligence often drives our decision whether or not to include …

Fish Pain: An Inconvenient Truth, Culum Brown

Culum Brown, PhD

Whether fish feel pain is a hot political topic. The consequences of our denial are huge given the billions of fish that are slaughtered annually for human consumption. The economic costs of changing our commercial fishery harvest practices are also likely to be great. Key outlines a structure-function analogy of pain in humans, tries to force that template on the rest of the vertebrate kingdom, and fails. His target article has so far elicited 34 commentaries from scientific experts from a broad range of disciplines; only three of these support his position. The broad consensus from the scientific community is …

A New Invasiveness Scale: Its Role In Reducing Animal Distress, Kenneth J. Shapiro, Peter B. Field

Kenneth J. Shapiro, PhD

No abstract provided.

Fish Pain's Burden Of Proof, Carl Safina

Animal Sentience

A hypothesis like Key’s, that fish cannot feel pain, should really be stated as a null hypothesis — an assumption that there is no difference in the things being compared. Then evidence — including anecdotal evidence — for and against rejecting the null hypothesis can be examined and weighed. Key (2016a) has proven only that fish lack mammalian brains.

Brain Processes For “Good” And “Bad” Feelings: How Far Back In Evolution?, Jaak Panksepp

Animal Sentience

The question of whether fish can experience pain or any other feelings can only be resolved by neurobiologically targeted experiments. This commentary summarizes why this is essential for resolving scientific debates about consciousness in other animals, and offers specific experiments that need to be done: (i) those that evaluate the rewarding and punishing effects of specific brain regions and systems (for instance, with deep-brain stimulation); (ii) those that evaluate the capacity of animals to regulate their affective states; and (iii) those that have direct implications for human affective feelings, with specific predictions — for instance, the development of new treatments …

Fish Pain: An Inconvenient Truth, Culum Brown

Animal Sentience

Whether fish feel pain is a hot political topic. The consequences of our denial are huge given the billions of fish that are slaughtered annually for human consumption. The economic costs of changing our commercial fishery harvest practices are also likely to be great. Key outlines a structure-function analogy of pain in humans, tries to force that template on the rest of the vertebrate kingdom, and fails. His target article has so far elicited 34 commentaries from scientific experts from a broad range of disciplines; only three of these support his position. The broad consensus from the scientific community is …

Why Fish Do Not Feel Pain, Brian Key

Animal Sentience

Only humans can report feeling pain. In contrast, pain in animals is typically inferred on the basis of nonverbal behaviour. Unfortunately, these behavioural data can be problematic when the reliability and validity of the behavioural tests are questionable. The thesis proposed here is based on the bioengineering principle that structure determines function. Basic functional homologies can be mapped to structural homologies across a broad spectrum of vertebrate species. For example, olfaction depends on olfactory glomeruli in the olfactory bulbs of the forebrain, visual orientation responses depend on the laminated optic tectum in the midbrain, and locomotion depends on pattern generators …