Mikhalevich & Powell (2020) argue that it is wrong, both scientifically and morally, to dismiss the evidence for sentience in invertebrates. They do not offer any examples, however, of how their welfare should be considered or improved. We draw on animal welfare science to suggest some ways that would not be excessively demanding.

There is no agreement on whether any invertebrates are conscious and no agreement on a methodology that could settle the issue. How can the debate move forward? I distinguish three broad types of approach: theory-heavy, theory-neutral and theory-light. Theory-heavy and theory-neutral approaches face serious problems, motivating a middle path: the theory-light approach. At the core of the theory-light approach is a minimal commitment about the relation between phenomenal consciousness and cognition that is compatible with many specific theories of consciousness: (...) the hypothesis that phenomenally conscious perception of a stimulus facilitates, relative to unconscious perception, a cluster of cognitive abilities in relation to that stimulus. This “facilitation hypothesis” can productively guide inquiry into invertebrate consciousness. What is needed? At this stage, not more theory, and not more undirected data gathering. What is needed is a systematic search for consciousness-linked cognitive abilities, their relationships to each other, and their sensitivity to masking. (shrink)

Invertebrate animals are usually seen as a kind of “aliens” which do not deserve any moral consideration. However, there is a growing amount of evidenceindicating that many of them do have the capacity to experience pain. The samecriteria that are usually applied in order to infer that vertebrates are sentient beings (behavioral response, learning capacity, memory, a certain specific neurophysiological structure…) lead to the idea that many invertebrates aresentient as well. Therefore, under the skeptical premise that we have no (...) directevidence of the experience of pain in vertebrates, we are forced to hold that itexists in both vertebrates and invertebrates. (shrink)

—Commentary on Mikhalevich and Powell on invertebrate minds.— 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.

There are several reasons to believe that there is a predominance of suffering over wellbeing in nature. The difference grows exponentially when the suffering of invertebrates is taken into consideration. Given the relevance of the experience of pain when it comes to attributing moral considerability to an individual, the seriousness and implications of the above statements are significant due to the need to reconcile the interests of an enormous number of individuals who experience pain to some degree. Depending on (...) the species and the ecosystem, there are variations that must be kept in mind with the aim of reducing the existing amount of suffering. (shrink)

Amongst invertebrates, molluscs show great variability in their nervous system ranging from primitive arrangement in Chitons to the complex mass of fused ganglia forming the ‘brain’ of cephalopods. Most of the effector organs used for pharmacological or physiological experiments. The neurosecretory cells (NSCs) with their combination of neuronal and glandular capabilities are perfectly suited to translate a neuronal input into the hormonal output best suited to long-term process. In this capacity, the NSCs may produce hormones, which act directly upon (...) the peripheral target or it may exert its effect indirectly by influencing the activity of other non-neural, endocrine organs. Neurosecretory cells have been detected in the cerebral, pedal and visceral ganglia of Lamellidens corrianus. The distribution and biology of freshwater bivalve like Lamellidens corrianus is influenced by local ecological factors (like temperature, pH, inorganic salts, type of soil etc.), water flow system and presence of micro-organisms, teleost fishes and seasonal variations in these parameters. Nitrogenous excretory changes which include ammonia in these molluscs is also influenced by these local ecological factors in which temperature is plays very crucial role. It is well known fact that the high stress conditions during drought or severe winter conditions have been conquered by several lineage of gastropods and sand bivalves and their ability to enter the resistant or dormant stages (low food) protein catabolism increased. Present investigation deals with the oxygen consumption and ammonia excretion ratio of these freshwater pelecypode Lamellidens corrianus. Study on Lemellidens corrianus directed in understanding the different behavioral and physiological aspects after cerebral ganglia removal and injection of their extracts revealed significant changes during summer (April-May). (shrink)

‘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. (shrink)

Sentience is the capacity to have feelings, such as feelings of pain, pleasure, hunger, thirst, warmth, joy, comfort and excitement. It is not simply the capacity to feel pain, but feelings of pain, distress or harm, broadly understood, have a special significance for animal welfare law. Drawing on over 300 scientific studies, we evaluate the evidence of sentience in two groups of invertebrate animals: the cephalopod molluscs or, for short, cephalopods (including octopods, squid and cuttlefish) and the decapod crustaceans or, (...) for short, decapods (including crabs, lobsters and crayfish). We also evaluate the potential welfare implications of current commercial practices involving these animals. (shrink)

We discuss the evolutionary transition from animals with limited experiencing to animals with unlimited experiencing and basic consciousness. This transition was, we suggest, intimately linked with the evolution of associative learning and with flexible reward systems based on, and modifiable by, learning. During associative learning, new pathways relating stimuli and effects are formed within a highly integrated and continuously active nervous system. We argue that the memory traces left by such new stimulus-effect relations form dynamic, flexible, and varied global sensory (...) states, which we call categorizing sensory states . These CSSs acquired a function: they came to act as internal “evaluators” and led to positive and negative reinforcement of new behavior. They are therefore the simplest, distinct, first-person motivational states that an animal can have. They constitute what we call basic consciousness, and are the hallmark of animals that can experience. Since associative learning has been found in many invertebrate taxa that first appeared during the Cambrian era, we propose that the processes underlying basic consciousness are phylogenetically ancient, and that their emergence may have fueled the Cambrian explosion. (shrink)

I commend Mikhalevich & Powell for extending the discussion of cognition and its relation to moral status with their well researched and argued target article on invertebrate cognition. I have two small criticisms: that the scala naturae still retains its appeal to some in biology as well as psychology, and that drawing the line at invertebrates requires a bit more defense given the larger comparative cognitive-scientific context.

On April 19, 2024, the New York Declaration on Animal Consciousness was announced at the “Emerging Science of Animal Consciousness” conference held at New York University. The New York Declaration is an effort to showcase a scientific consensus on the presence of conscious experiences across all vertebrates (including reptiles, amphibians, and fish) and many invertebrates (at least including cephalopods, decapod crustaceans, and insects). Scientifically, the New York Declaration marks a significant advancement for humanity. However, it also brings heightened awareness (...) to the moral challenges associated with animals that have conscious experiences (or phenomenal consciousness). This article will discuss philosophical approaches to the moral issue of killing sentient beings, thereby highlighting an existing moral dilemma in human society: In sustaining human survival, a species considered to have morality, we have to violate our own moral standards by killing other species with intrinsic value, consciousness, or sentience. This moral dilemma has long been present in human society. Various solutions have been proposed and implemented in practice to address this issue, such as the non-violence and vegetarian approach of Buddhism, the application of Islamic law and sacred rituals to animals in Islam, animal rights movements and voluntary extinction in Western countries, and the technology producing meat using animal cells. However, despite these approaches, we have not yet been able to fully resolve the dilemma, as sentient beings continue to be killed for our survival. We believe the most feasible solution is to change the current food consumption culture, build an eco-surplus culture to mitigate climate change, prevent deforestation, and promote peace. (shrink)

This paper explores the idea that many “simple minded” invertebrates are “natural zombies” in that they utilize their senses in intelligent ways, but without phenomenal awareness. The discussion considers how “first-order” representationalist theories of consciousness meet the explanatory challenge posed by blindsight. It would be an advantage of first-order representationalism, over higher-order versions, if it does not rule out consciousness in most non-human animals. However, it is argued that a first-order representationalism which adequately accounts for blindsight also implies that (...) most non-mammals are not conscious. The example of the honey bee is used to illuminate these claims. Although there is some reason to think that bees have simple beliefs and desires, nevertheless, their visually-mediated cognizing is comparable to that of an animal with blindsight. There is also reason to think that the study of blindsight can also help determine how consciousness is distributed in the animal world. (shrink)

What can the creation of artificial habitats to replace old-growth forests tell us about the process, value and future of design? This chapter takes a concrete and provocative example and uses it to rethink design as a gradual, ecological action. To illustrate this understanding, the chapter begins with a description of a proposal to provide artificial habitats for wild animals such as birds, bats and invertebrates. The controversial idea to replace rapidly disappearing old-growth trees with artificial structures puts in (...) doubt habitual assumptions about the clients, procedures and goals of design. This example is of relevance to all design because the need to provide artificial habitats to nonhumans will be increasingly common under the influence of such phenomena as global warming or urbanisation. … The invention of artificial structures in place of natural habitats is described in this chapter as an incitement that highlights the need for further research into values, participants and methods of design. This discussion concludes with a proposal for an attitude of modesty in the face of increasingly overwhelming volumes of information as well as in the presence of an even greater ignorance about the futures of nondeterministic, volatile and incompletely controllable natural systems. The dilemma of design in these conditions is in the tension between its remit to act and the uncertainty that inescapably underlies any creative endeavour. (shrink)

This selective review explores biologically inspired learning as a model for intelligent robot control and sensing technology on the basis of specific examples. Hebbian synaptic learning is discussed as a functionally relevant model for machine learning and intelligence, as explained on the basis of examples from the highly plastic biological neural networks of invertebrates and vertebrates. Its potential for adaptive learning and control without supervision, the generation of functional complexity, and control architectures based on self-organization is brought forward. Learning (...) without prior knowledge based on excitatory and inhibitory neural mechanisms accounts for the process through which survival-relevant or task-relevant representations are either reinforced or suppressed. The basic mechanisms of unsupervised biological learning drive synaptic plasticity and adaptation for behavioral success in living brains with different levels of complexity. The insights collected here point toward the Hebbian model as a choice solution for “intelligent” robotics and sensor systems. Keywords: Hebbian learning; synaptic plasticity; neural networks; self-organization; brain; reinforcement; sensory processing; robot control . (shrink)

Mikhalevich & Powell are to be commended for challenging the “invertebrate dogma” that invertebrates are unworthy of ethical concern. However, developing an evolutionarily inclusive ethics requires facing some of the more radical implications of rejecting hierarchical scala naturae and human-centered conceptions of the biological world. In particular, we need to question the anthropocentric assumptions that still linger in discussions like these.

Can octopuses feel pain and pleasure? What about crabs, shrimps, insects, or spiders? How do we tell whether a person unresponsive after severe brain injury might be suffering? When does a fetus in the womb start to have conscious experiences? Could there even be rudimentary feelings in miniature models of the human brain, grown from human stem cells? And what about AI? These are questions about the edge of sentience, and they are subject to enormous, disorienting uncertainty. The stakes are (...) immense, and neglecting the risks can have terrible costs. We need to err on the side of caution, yet it’s often far from clear what ‘erring on the side of caution’ should mean in practice. When are we going too far? When are we not doing enough? The Edge of Sentience presents a comprehensive precautionary framework designed to help us reach ethically sound, evidence-based decisions despite our uncertainty. (shrink)

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. (shrink)