Ecology and Evolutionary Biology Commons^™

Where Is Pain In The Brain?, Marshall Devor

Animal Sentience

Key argues that fish cannot experience pain based on (1) brain imaging in humans, (2) consequences of lesions and (3) direct brain stimulation. Imaging indeed shows that pain-relevant signals reach the cortex, but not that they underlie the subjective experience of pain. Lesions and stimulation data are more to the point, but Key paints an idiosyncratic and misleading picture of their effects. S1 and S2 ablation does not eliminate evoked or spontaneous pain, although there may be up- or down-modulation. Likewise, stimulation of pain-associated cortical areas rarely induces pain, and pain almost never occurs at the onset of epileptic seizures. …

Falsifying The Null Hypothesis That “Fish Do Not Feel Pain", Brian Key

Animal Sentience

The reader of Animal Sentience may surmise that because the weight of the commentaries on my target article, “Why fish do not feel pain,” is leaning towards not supporting my argument, it follows that the premise "fish do not feel pain" is incorrect. However, science does not prevail by popular opinion. History is plagued with numerous (and often widely accepted) examples of biological phenomena being explained by mysterious forces. In the absence of a mechanistic understanding, the many different guises of vitalism (the principle that life involves a vital energy) are often invoked to explain the unknown. Spurious …

Constructing A River, Building A Border: An Environmental History Of Irrigation, Water Law, State Formation, And The Rio Grande Rectification Project In The El Paso/Juárez Valley, Joanne Kropp

Open Access Theses & Dissertations

The Rio Grande in the El Paso, Texas, U.S./Juárez, Chihuahua, Mexico, Valley has a long history of human use from prehistoric to modern times. Formal irrigation began in the 1600s, mainly for viticulture, changing to cotton and pecans in the 1900s. The Rio Grande was subject to bed shifting and flooding that, after 1848, affected the location of the international boundary. During the Great Depression the U.S. and Mexican governments sponsored conservation projects to provide jobs and increase agricultural production. The 1933 “Convention - Rectification of the Rio Grande” was the culmination of interstate and bi-national agreements to divide Rio …

The Curiosity Of Con, Petrified Breath, And An Accident Known As Blue., Steven Randall

Theses and Dissertations

My thesis installation emerged from an interest in visualizing breath. The resulting work came to exist at the intersection between art, biology, and performance.

The unicorn tapestries were used as a generative point of departure to explore the preservation and transformation of images through time, by time, and with time. Reproductions of the six tapestries were each etched into paper and then submerged into solutions of Phenol Red dye, Ferric Ferrocyanide (also known as Prussian Blue), and various forms of sodium chloride. Exhaled breath was used to encrust these images of the tapestries into physical objects which gradually crystallized and …

Pain In Parallel, Peter Godfrey-Smith

Animal Sentience

Key's (2016) arguments against the view that fish feel pain can be shown to be fallacious by considering some damage-related behaviors in invertebrates. Pain may have different neural bases in different organisms, so the absence in fish of the cortical structures that might underlie pain in mammals does not settle the question of fish pain.

Nonverbal Indicators Of Pain, Simon Van Rysewyk

Animal Sentience

In discussing fish pain, Key (2016) privileges pain in humans — “the only species able to directly report on its feelings.” Human experience of pain is not necessarily best reflected by verbal self-report, however. Neural responses to noxious stimuli are influenced by individual differences and by context. Nonverbal pain displays such as facial expressions reflect part of the neural response to noxious stimuli. Most mammals have a specific facial grimace reflecting pain. If fish have a somatic expression of pain, the development of a reliable and accurate somatic pain scale specific to fish could make a contribution to the debate …

Why Human Pain Can’T Tell Us Whether Fish Feel Pain, Victoria A. Braithwaite, Paula Droege

Animal Sentience

In his target article, Key (2016) reviews the neuroanatomy of human pain and uses what is known about human pain to argue that fish cannot experience pain. We provide three reasons why the conclusions reached by Key are unsupported. They consider (i) why it is not sufficient to conclude that only human neural structures can process conscious pain, (ii) why an understanding of pain in humans and non-human animals needs to be based within a framework of consciousness, and (iii) evidence already exists that fish treated with noxious stimuli lose the ability to perform normal behaviours: This was a behavioral …

An Invertebrate Perspective On Pain, Jennifer A. Mather

Animal Sentience

Although Key (2016) argues that mammals feel pain and fish do not, from an invertebrate perspective, it is obvious that the pain experience is shared by animals from a number of different animal groups.

Pain In Fish: Weighing The Evidence, James D. Rose

Animal Sentience

The target article by Key (2016) examines whether fish have brain structures capable of mediating pain perception and consciousness, functions known to depend on the neocortex in humans. He concludes, as others have concluded (Rose 2002, 2007; Rose et al. 2014), that such functions are impossible for fish brains. This conclusion has been met with hypothetical assertions by others to the effect that functions of pain and consciousness may well be possible through unknown alternate neural processes. Key's argument would be bolstered by consideration of other neurological as well as behavioral evidence, which shows that sharks and ray are fishes …

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

Animal Sentience

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 …

Why Is Fish “Feeling” Pain Controversial?, E. Don Stevens

Animal Sentience

In his excellent target article, Key (2016) develops a mechanistic argument in an attempt to show why it is unlikely that fish can “feel” pain or for that matter, “feel” anything. The topic is controversial and likely to achieve the goal of getting many hits for the inaugural issue of the new journal, Animal Sentience. In my view, the question is unlikely to be answered, for two reasons. First, because the proponents of the “fish feel pain” controversy are untrained and unskilled in the details and jargon of neurophysiology and/or neuroanatomy, and the opponents of the controversy, like Key, …

How Not To Move The Line Drawn On Pain, Bjorn H. Merker

Animal Sentience

In this second commentary I outline the inadequacy of Key's responses to the many peer critiques of his thesis that have so far appeared in Animal Sentience. I illustrate with examples drawn from his response to my first commentary.

Could Fish Feel Pain? A Wider Perspective, Yew-Kwang Ng

Animal Sentience

Key’s (2016) target article provides some strong arguments but also makes some logical mistakes. The arguments are not sufficient to support a definite conclusion that fish cannot feel pain. A multi-faceted perspective taking into account brain structure, chemical secretion in brain, animal behavior, and evolutionary biology may be useful and appears, at least in some aspects, to suggest the opposite conclusion from that of the target article.

Should Fish Feel Pain? A Plant Perspective, František Baluška

Animal Sentience

Key (2016) claims fish that fish do not feel pain because they lack the necessary neuronal architecture: their responses to noxious stimuli, according to Key, are executed automatically without any feelings. However, as pointed out by many of his commentators, this conclusion is not convincing. Plants might provide some clues. Plants are not usually thought to be very active behaviorally, but the evidence suggests otherwise. Moreover, in stressful situations, plants produce numerous chemicals that have painkilling and anesthetic properties. Finally, plants, when treated with anesthetics, cannot execute active behaviors such as touch-induced leaf movements or rapid trap closures after localizing …

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 …

Fish Pain: A Painful Topic, Carl Safina

Animal Sentience

If fish cannot feel pain, why do stingrays have purely defensive tail spines that deliver venom? Stingrays’ ancestral predators are fish. And why do many fishes possess defensive fin spines, some also with venom that produces pain in humans? These things did not evolve just in case sentient humans would evolve millions of years later and then invent scuba. If fish react purely unconsciously to “noxious” stimuli, why aren’t sharp jabbing spines enough? Why also stinging venom?

Pain-Capable Neural Substrates May Be Widely Available In The Animal Kingdom, Edgar T. Walters

Animal Sentience

Neural and behavioral evidence from diverse species indicates that some forms of pain may be generated by coordinated activity in networks far smaller than the cortical pain matrix in mammals. Studies on responses to injury in squid suggest that simplification of the circuitry necessary for conscious pain might be achieved by restricting awareness to very limited information about a noxious event, possibly only to the fact that injury has occurred, ignoring information that is much less important for survival, such as the location of the injury. Some of the neural properties proposed to be critical for conscious pain in mammals …

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 …

Cognitive Evidence Of Fish Sentience, Jonathan Balcombe

Animal Sentience

I present a little-known example of flexible, opportunistic behavior by a species of fish to undermine Key’s (2016) thesis that fish are unconscious and unable to feel. Lack of a cortex is flimsy grounds for denying pain to fish, for on that criterion we must also then deny it to all non-mammals, including birds, which goes against scientific consensus. Notwithstanding science’s fundamental inability to prove anything, the precautionary principal dictates that we should give the benefit of the doubt to fish, and the state of the oceans dictates that we act on it now.

Fish Lack The Brains And The Psychology For Pain, Stuart W.G. Derbyshire

Animal Sentience

Debate about the possibility of fish pain focuses largely on the fish’s lack of the cortex considered necessary for generating pain. That view is appealing because it avoids relatively abstract debate about the nature of pain experience and subjectivity. Unfortunately, however, that debate cannot be entirely avoided. Subcortical circuits in the fish might support an immediate, raw, “pain” experience. The necessity of the cortex only becomes obvious when considering pain as an explicitly felt subjective experience. Attributing pain to fish only seems absurd when pain is considered as a state of explicit knowing.

What Would The Babel Fish Say?, Monica Gagliano

Animal Sentience

Starting with its title, Key’s (2016) target article advocates the view that fish do not feel pain. The author describes the neuroanatomical, physiological and behavioural conditions involved in the experience of pain in humans and rodents and confidently applies analogical arguments as though they were established facts in support of the negative conclusion about the inability of fish to feel pain. The logical reasoning, unfortunately, becomes somewhat incoherent, with the arbitrary application of the designated human criteria for an analogical argument to one animal species (e.g., rodents) but not another (fish). Research findings are reported selectively, and questionable interpretations are …

Modulation Of Behavior In Communicating Emotion, Martin Gardiner

Animal Sentience

King discusses many examples where two animals, as they bond, behave in ways we interpret as expressing love for one another. If one of the bonded animals then dies, signs of loving are replaced by signs we interpret as expressing grief by the animal who remains. I propose a pathway for emotional communication between an animal and an observer that can have a central role in these and other observations by King and in our overall ability to interpret observed behavior in relation to emotion. This pathway provides evidence of emotion in an observed animal by communicating evidence of emotion’s …

Spinning Our Wheels And Deepening The Divide: Call For An Evidence-Based Approach To The Fish Pain Debate, Steven J. Cooke

Animal Sentience

There is vigorous ongoing debate about whether fish feel pain and have the capacity to suffer. The body of literature dedicated to the topic is increasing but what is particularly problematic is that the majority of the contributions represent opinion pieces and thus fall within the realm of advocacy. Many of the empirical research papers purporting that fish do or do not feel pain have problems with cavalier use of definitions, poor experimental design, or statistical/technical issues and tend to include advocacy statements in their interpretations. Rather than continuing to spin our wheels and deepen the divide, I would advocate …

Pain And Fish Welfare, Eliane Gonçalves-De-Freitas

Animal Sentience

The evolutionary approach of Key’s (2016) target article, generically comparing humans with fish of all kinds, is simplistic. The author ignores published research on structural and molecular aspects of pain in fish. The target article reads more like a selective polemic against fish welfare than an even-handed analysis.

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 …

Animal Sentience: The Other-Minds Problem, Stevan Harnad

Animal Sentience

The only feelings we can feel are our own. When it comes to the feelings of others, we can only infer them, based on their behavior — unless they tell us. This is the “other-minds problem.” Within our own species, thanks to language, this problem arises only for states in which people cannot speak (infancy, aphasia, sleep, anaesthesia, coma). Our species also has a uniquely powerful empathic or “mind-reading” capacity: We can (sometimes) perceive from the behavior of others when they are in states like our own. Our inferences have also been systematized and operationalized in biobehavioral science …

Nonhuman Mind-Reading Ability, Marthe Kiley-Worthington

Animal Sentience

Harnad (2016) is mistaken that humans are better at mind-reading than other species. Humans have context-independent language, but nonhuman species, especially mammals, have context-dependent nonverbal skills – perceptual, communicative and social -- that can be much keener than our own.

Considering Animals’ Feelings: Précis Of Sentience And Animal Welfare (Broom 2014), Donald M. Broom

Animal Sentience

The concept of sentience concerns the capacity to have feelings. There is evidence for sophisticated cognitive concepts and for both positive and negative feelings in a wide range of nonhuman animals. All vertebrates, including fish, as well as some molluscs and decapod crustaceans have pain systems. Most people today consider that their moral obligations extend to many animal species. Moral decisions about abortion, euthanasia, and the various ways we protect animals should take into account the research findings about sentience. In addition, all animal life should be respected and studies of the welfare of even the simplest invertebrate animals should …

Sentience And Animal Welfare: Affirming The Science And Addressing The Skepticism, Nancy Clarke

Animal Sentience

Broom’s (2014) book is a well-researched and thoroughly written exploration and evaluation of the journey from the origins of animal welfare science to what we can say we now know and need to consider in relation to animal sentience and welfare. This book will help to counter any skepticism among academics and policy makers.

Is Sentience Only A Nonessential Component Of Animal Welfare?, Ian J.H. Duncan

Animal Sentience

According to Broom (2014), animal welfare is a concept that can be applied to all animals, including single-celled organisms that are obviously not sentient. Such a stance makes it difficult to draw a connection between welfare and sentience, and that is the book’s downfall. Some excellent points are made about sentience and there are very good discussions on animal welfare. However, unless sentience is considered the essential component of welfare, any attempt to link the two phenomena will be unsuccessful — and that, indeed, is the case with this book.