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Full-Text Articles in Life Sciences

Plants Lack The Functional Neurotransmitters And Signaling Pathways Required For Sentience In Animals, David G. Robinson, Michael R. Blatt, Andreas Draguhn, Lincoln Taiz, Jon Mallatt Apr 2023

Plants Lack The Functional Neurotransmitters And Signaling Pathways Required For Sentience In Animals, David G. Robinson, Michael R. Blatt, Andreas Draguhn, Lincoln Taiz, Jon Mallatt

Animal Sentience

We cannot agree with Segundo-Ortin and Calvo that plants are sentient organisms. We have critically examined several aspects of their target article, and find their claims are not supported by the published evidence. We address these claims in sections on whether plants have a ‘neurobiology’ analogous to that of animal nervous systems, including neurotransmitters and synaptic receptors that respond to anesthetics; and whether plant signaling resembles neural transmission. For the latter, we especially consider the unique way plants signal their responses to wounding. Although the plant vascular system has been compared to the animal nervous system, animal blood vessels would …


Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo Jan 2023

Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo

Animal Sentience

A growing number of non-human animal species are being seriously considered as candidates for sentience, but plants are either forgotten or explicitly excluded from these debates. In our view, this is based on the belief that plant behavior is hardwired and inflexible and on an underestimation of the role of plant electrophysiology. We weigh such assumptions against the evidence to suggest that it is time to take seriously the hypothesis that plants, too, might be sentient. We hope this target article will serve as an invitation to investigate sentience in plants with the same rigor as in non-human animals.


Sentience In Decapod Crustaceans: A General Framework And Review Of The Evidence, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch Jan 2022

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, …


Animal Sentience Research: Synthesis And Proposals, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch Jan 2022

Animal Sentience Research: Synthesis And Proposals, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch

Animal Sentience

Most commentaries on our target article broadly support our approach to evaluating evidence of animal sentience. In this Response, we clarify the framework’s purpose and address criticisms of our criteria. A recurring theme is that a framework to synthesise current evidence of sentience is not the same as an agenda for future directions in animal sentience research. Although future directions are valuable, our framework aims to evaluate existing evidence and inform animal welfare legislation.


All Living Organisms Are Sentient, Arthur S. Reber, Frantisek Baluska, William B. Miller Jr. Jan 2022

All Living Organisms Are Sentient, Arthur S. Reber, Frantisek Baluska, William B. Miller Jr.

Animal Sentience

We argue that all living organisms, from the simplest unicellular prokaryotes to Homo sapiens, have valenced experiences—feelings as states of preference—and are capable of cognitive representations. Bacteria can learn, form stable memories, and communicate, hence solve problems. Rowan et al.'s statement that "Subjective feelings are just that — subjective — and are available only to the animal (or human) experiencing them" is true but irrelevant. When we see a fish flopping about in the bottom of a boat we immediately recognize suffering without having a glimpse of the nature of piscine distress. Some controlled anthropomorphism can go a …


Legal Recognition Of Animal Sentience: The Case For Cautious Optimism, Jane Kotzmann Jan 2022

Legal Recognition Of Animal Sentience: The Case For Cautious Optimism, Jane Kotzmann

Animal Sentience

Rowan et al.’s target article provides a valuable indication of the work that was required to reach the point where animals are recognised as sentient in various laws. To ensure this work was not in vain, the language of sentience needs to be used as a moral currency to demand further cultural change involving greater human respect for animals.


The Science Of Animal Sentience And The Politics Of Animal Welfare Should Be Kept Separate, Marian Stamp Dawkins Jan 2022

The Science Of Animal Sentience And The Politics Of Animal Welfare Should Be Kept Separate, Marian Stamp Dawkins

Animal Sentience

Although linked historically by Rowan et al., the scientific study of animal sentience and political campaigns to improve animal welfare should be kept separate, for at least two reasons. First, the separation makes it clear that standards of evidence acceptable for ethical or political decisions on animal welfare can be lower than those required for a rigorously scientific approach to animal sentience. Second, it helps to avoid confirmatory bias in the form of giving undue weight to results that are in line with pre-conceived ideas and political views.


Pain Sentience Criteria And Their Grading, Eva Jablonka, Simona Ginsburg Jan 2022

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.


Truly Minimal Criteria For Animal Sentience, Mark Solms Jan 2022

Truly Minimal Criteria For Animal Sentience, Mark Solms

Animal Sentience

The criteria for determining animal sentience proposed in the target article are sensible but they lack an explicit functional justification for the focus on pain. This commentary provides an abbreviated account of the most basic functional principles that underpin animal sentience and articulates some minimal criteria for determining its presence.


Crustacean Pain, Michael Tye Jan 2022

Crustacean Pain, Michael Tye

Animal Sentience

This commentary discusses the target article’s methodology, the relevance of the claim that crustaceans lack a neocortex to the thesis that they feel pain, and the evaluation of the results of some trade-off experiments done with hermit crabs.


No Need For Certainty In Animal Sentience, Yew Kwang Ng Jan 2022

No Need For Certainty In Animal Sentience, Yew Kwang Ng

Animal Sentience

This commentary supports Crump et al.’s (2022) point that where risks to welfare are severe, strong evidence of sentience is sufficient to warrant protecting welfare. Crump et al.’s eight criteria for sentience are also useful. Flexible decision-making (5) and flexible behaviour (6) are consistent with Ng (1995). The concession that the “no-need-for-sentience” proposition is unnecessary also strengthens the importance of the target article’s conclusions.


Decapod Sentience: Broadening The Framework, Cecilia De Souza Valente Jan 2022

Decapod Sentience: Broadening The Framework, Cecilia De Souza Valente

Animal Sentience

A framework for studying sentience in decapods is of great value, but how high a cost (in suffering) to each individual decapod (or any animal) is warranted for collecting scientific evidence of sentience? The lack of evidence for some of the target article’s proposed criteria surely results from the fact that research is focused mainly on biomedical studies, ecotoxicology, and commercial production, with decapod sentience and welfare seen as only a secondary research topic. I draw attention also to the possibility of a wider framework that includes all felt experiences, from suffering to pleasure.


Sentience In Decapods: Difficulties To Surmount, Michael L. Woodruff Jan 2022

Sentience In Decapods: Difficulties To Surmount, Michael L. Woodruff

Animal Sentience

In the target article Crump et al. present 8 criteria to assess whether decapods experience pain. Four of these -- sensory integration, motivational trade-offs, flexible self-protection, and associative learning -- could be used to assess sentience in general. In this commentary I discuss difficulties with using these criteria to provide evidence of sentience in decapods, particularly if this evidence is to change public opinion and policies. These difficulties are lack of evidence, the potential to eventually explain the neurobiological basis of the behaviors chosen as criteria, thereby eliminating any explanatory work for sentience, and the reluctance to bring animals that …


Pain In Pleocyemata, But Not In Dendrobranchiata?, Gary Comstock Jan 2022

Pain In Pleocyemata, But Not In Dendrobranchiata?, Gary Comstock

Animal Sentience

Crump et al.’s contribution to assessing whether decapods feel pain raises an important question: Is pain distributed unevenly across the order? The case for pain appears stronger in Pleocyemata than in Dendrobranchiata. Some studies report pain avoidance behaviors in Dendrobranchiata (Penaeidae) shrimp, but further studies are needed to determine whether the chemicals used are acting as analgesics to relieve pain, or as soporifics to reduce overall alertness. If the latter, the most farmed shrimp species may not require the same level of protection as crabs, crayfish, and lobsters.


Distinguishing Epistemic And Moral Grounds For Legal Protection, Carlos Montemayor Jan 2022

Distinguishing Epistemic And Moral Grounds For Legal Protection, Carlos Montemayor

Animal Sentience

The criteria proposed by Crump et al. are based on various cognitive roles associated with sentience. A subset of them may be sufficient for certain kinds of welfare, but the presence of all of them should be considered as clearly sufficient for substantial kinds of legal protection based on their relation to capacities that we consider essential for moral standing in human beings.


Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters Jan 2022

Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters

Animal Sentience

Evidence for sentience in animals distantly related to humans is often sought in observations of behavioral and neural responses to noxious stimuli that would be painful in humans. Most proposed criteria for painful sentience in “lower” animals such as decapod crustaceans have no necessary links to the affective (“suffering”) component of pain. The best evidence for painful affect in animals is learned aversion to stimuli associated with noxious experience, and conditioned preference for contexts associated with relief from aversive consequences of noxious experience, as expressed in voluntary behavior. Such evidence is currently lacking for any invertebrate except octopus.


What Might Decapod Sentience Mean For Policy, Practice, And Public?, Richard Gorman Jan 2022

What Might Decapod Sentience Mean For Policy, Practice, And Public?, Richard Gorman

Animal Sentience

Crump et al. provide eight criteria for evaluating sentience in decapods, with scope for for application to other taxa. Their work has attracted the interest of policymakers. This commentary discusses the limitations of conceptual and legal acknowledgement of sentience in chainging practice and public attitudes. More work is needed. Social science may be able to help.


Does The Sentience Framework Imply All Animals Are Sentient?, Kristin Andrews Jan 2022

Does The Sentience Framework Imply All Animals Are Sentient?, Kristin Andrews

Animal Sentience

The eight criteria proposed in Crump et al.’s framework for evaluating pain sentience in decapod crustaceans are just the tip of the iceberg when it comes to markers that could increase confidence in an animal’s sentience more generally. Some of the commentaries have already pointed out that pain is only one kind of sentience (Souza Valente). It has also already been pointed out that there are other criteria for pain that could be usefully added to the framework’s eight (Burrell). This expansive thinking about criteria that can be used to increase confidence in sentience raisess the question: in an expansive …


Decapod Sentience: Promising Framework And Evidence, Jon Mallatt, Todd E. Feinberg Md Jan 2022

Decapod Sentience: Promising Framework And Evidence, Jon Mallatt, Todd E. Feinberg Md

Animal Sentience

Strong points of the target article by Crump et al. are that it offers clear criteria for judging whether decapods are sentient, an effective semi-quantitative grading system for this purpose, and an astute, critical review of the literature. It concludes plausibly that major subgroups of decapods are sentient. A minor problem is that it includes classical, Pavlovian learning as a marker of sentience along with the more valid marker of complex (e.g., operant) learning. Another minor problem is that it does not distinguish results that are negative because of likely absence of sentience from results that are negative because they …


Decapods As Food, Companions And Research Animals: Legal Impact Of Ascribing Sentience, Jonathan J. Cooper, Ambrose Tinarwo, Beth A. Ventura Jan 2022

Decapods As Food, Companions And Research Animals: Legal Impact Of Ascribing Sentience, Jonathan J. Cooper, Ambrose Tinarwo, Beth A. Ventura

Animal Sentience

This commentary provides an overview of the practical implications of attributing sentience to protect decapods as food, companion and research animals in the UK context. Recognising their capacity to suffer has implications for humane slaughter in farming and fishing sectors. It should also place a greater duty of care on owners of captive decapods, considering their needs and avoiding unnecessary suffering. The recognition of decapod sentience should also have an impact on their protection as research animals, although research with a potential to cause suffering may be needed to better understand decapods’ capacity to suffer.


Pros And Cons Of A Framework For Evaluating Potential Pain In Decapods, Robert W. Elwood Jan 2022

Pros And Cons Of A Framework For Evaluating Potential Pain In Decapods, Robert W. Elwood

Animal Sentience

The rigorous framework for research into potential pain in decapods was successful in allowing legislators in the United Kingdom to evaluate a complex scientific issue. However, it might produce problems for research. I discuss doubts about the usefulness of the eight criteria. Some have yet to receive any investigation and others do not allow much inference about pain. In addition, some existing studies are not covered in the framework. Most worrying, however, is the potential for stifling future research of novel areas that are excluded from the framework.


A Framework For Evaluating Evidence Of Pain In Animals, Matilda Gibbons, Lars Chittka Jan 2022

A Framework For Evaluating Evidence Of Pain In Animals, Matilda Gibbons, Lars Chittka

Animal Sentience

Crump et al. define eight criteria indicating sentience in animals, with a focus on pain. Here, we point out the risk of false negative or false positive diagnoses of pain. Criteria of different levels of inclusivity are useful for using the precautionary principle in animal welfare considerations, and for more formal scientific evidence of pain. We suggest tightening the criteria -- from more general evidence of sentience to pain alone -- because crucial evidence for animal welfare decisions might otherwise be missed for animals subjected to invasive and injurious procedures.


Sentience Politics : A Fishy Perspective, Culum Brown Jan 2022

Sentience Politics : A Fishy Perspective, Culum Brown

Animal Sentience

The plight of fishes has almost certainly got worse since Bentham (1789) coined the phrase “The question is not Can they reason? nor, Can they talk? but Can they suffer?” Despite the fact that fishes are increasingly recognised as sentient animals worthy of protection under animal welfare legislation in many countries around the world, fishing practices are almost universally exempt activities. The human population continues to grow, and, surprisingly, per capita intake of fish is still increasing (FAO 2020). The source of this fish is not wild stocks (catches of which have remained more or less stagnant for …


The Reality And Prevalence Of Animal Sentience, Antonio Damasio Jan 2022

The Reality And Prevalence Of Animal Sentience, Antonio Damasio

Animal Sentience

Rowan et al use findings from neurobiology, clinical neurology, and general biology to argue for the extensive presence of sentience in animals, but they are wisely cautious concerning when in the phylogenetic scale that emergence occurred.


Why The Recognition Of Sentience Is So Important For Animal Welfare, Mark Jones Jan 2022

Why The Recognition Of Sentience Is So Important For Animal Welfare, Mark Jones

Animal Sentience

Rowan et al. (2022) provide a useful summary of the history and development of the philosophical, public, and legal recognition of animal sentience and its importance in improving the welfare of animals. Here I argue for the incorporation of the precautionary principle in sentience recognition, and the wider significance of sentience recognition to the current climate, biodiversity and human health crises.


Defending Human Difference By Raising The Bar, Joe Gough Jan 2022

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.


Intensive Animal Farming Conditions Are A Major Threat To Global Health, Cynthia Schuck-Paim Aug 2020

Intensive Animal Farming Conditions Are A Major Threat To Global Health, Cynthia Schuck-Paim

Animal Sentience

Wiebers & Feigin accurately propose that reducing the risks posed by infectious disease outbreaks and other global health challenges will depend critically on transitioning away from intensive animal farming practices. Creating the right incentive structure for this transition to happen is one of the great challenges in the years to come, but a much-needed step to ensure the health and well-being of current and future generations.


Consider The Agent In The Arthropod, Nicolas Delon, Peter Cook, Gordon Bauer, Heidi Harley Jul 2020

Consider The Agent In The Arthropod, Nicolas Delon, Peter Cook, Gordon Bauer, Heidi Harley

Animal Sentience

Whether or not arthropods are sentient, they can have moral standing. Appeals to sentience are not necessary and retard progress in human treatment of other species, including invertebrates. Other increasingly well-documented aspects of invertebrate minds are pertinent to their welfare. Even if arthropods are not sentient, they can be agents whose goals—and therefore interests—can be frustrated. This kind of agency is sufficient for moral status and requires that we consider their welfare.


Brain Complexity, Sentience And Welfare, Donald M. Broom Jul 2020

Brain Complexity, Sentience And Welfare, Donald M. Broom

Animal Sentience

Neither sentience nor moral standing is confined to animals with large or human-like brains. Invertebrates deserve moral consideration. Definition of terms clarifies the relationship between sentience and welfare. All animals have welfare but humans give more protection to sentient animals. Humans should be less human-centred.


Invertebrate Cognition, Sentience And Biology, Georges Chapouthier Jul 2020

Invertebrate Cognition, Sentience And Biology, Georges Chapouthier

Animal Sentience

All animal species have adapted for survival and no species is superior overall. For cognitive capacities and sentience, invertebrates such as the octopus, although quite unlike vertebrates, can achieve similar performance levels. So can other invertebrates with small brains; hence they too, as sentient beings, deserve moral consideration from humans. How are we to identify these species? Only though a detailed analysis of their behavior. The decision, which is a moral judgment, depends on biological knowledge that still needs to be acquired.