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 in the spinal cord throughout vertebrate phylogeny, from fish to humans. Here I delineate the region of the human brain that is directly responsible for feeling painful stimuli. The principal structural features of this region are identified and then used as biomarkers to infer whether fish are, at least, anatomically capable of feeling pain. Using this strategy, I conclude that fish lack the necessary neurocytoarchitecture, microcircuitry, and structural connectivity for the neural processing required for feeling pain.

Author Biography

Brian Key brian.key@uq.edu.au is Head of the Brain Growth and Regeneration Lab at the University of Queensland, dedicated to understanding the principles of stem cell biology, differentiation, axon guidance, plasticity, regeneration and development of the brain.

Address: School of Biomedical Sciences, University of Queensland, Brisbane 4072, Australia






Article Thread

Key, Brian (2016) Why fish do not feel pain. Animal Sentience 3(1)

Balcombe, Jonathan (2016) Cognitive evidence of fish sentience. Animal Sentience 3(2)

Braithwaite, Victoria A. and Droege, Paula (2016) Why human pain can’t tell us whether fish feel pain. Animal Sentience 3(3)

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Brown, Culum (2016) Comparative evolutionary approach to pain perception in fishes. Animal Sentience 3(5)

Chella, Antonio (2016) Robot fish do not need sentience. Animal Sentience 3(6)

Dinets, Vladimir (2016) No cortex, no cry. Animal Sentience 3(7)

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Jones, Robert C. (2016) Fish sentience and the precautionary principle. Animal Sentience 3(10)

Manzotti, Riccardo (2016) No evidence that pain is painful neural process. Animal Sentience 3(11)

Mather, Jennifer A. (2016) An invertebrate perspective on pain. Animal Sentience 3(12)

Ng, Yew-Kwang (2016) Could fish feel pain? A wider perspective. Animal Sentience 3(13)

Seth, Anil K. (2016) Why fish pain cannot and should not be ruled out. Animal Sentience 3(14)

Striedter, Georg (2016) Lack of neocortex does not imply fish cannot feel pain. Animal Sentience 3(15)

Key, Brian (2016) Going beyond just-so stories. Animal Sentience 3(38)

Baluška, František (2016) Should fish feel pain? A plant perspective. Animal Sentience 3(16)

Burghardt, Gordon (2016) Mediating claims through critical anthropomorphism. Animal Sentience 3(17)

Derbyshire, Stuart W.G. (2016) Fish lack the brains and the psychology for pain. Animal Sentience 3(18)

Elwood, Robert W. (2016) A single strand of argument with unfounded conclusion. Animal Sentience 3(19)

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Godfrey-Smith, Peter (2016) Pain in parallel. Animal Sentience 3(21)

Gonçalves-de-Freitas, Eliane (2016) Pain and fish welfare. Animal Sentience 3(22)

Merker, Bjorn (2016) Drawing the line on pain. Animal Sentience 3(23)

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Shriver, Adam J. (2016) Cortex necessary for pain — but not in sense that matters. Animal Sentience 3(27)

Sneddon, Lynne U. and Leach, Matthew C. (2016) Anthropomorphic denial of fish pain. Animal Sentience 3(28)

Stevens, E. Don (2016) Why is fish “feeling” pain controversial?. Animal Sentience 3(29)

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Wadiwel, Dinesh Joseph (2016) Fish and pain: The politics of doubt. Animal Sentience 3(31)

Key, Brian (2016) Falsifying the null hypothesis that “fish do not feel pain". Animal Sentience 3(39)

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Merker, Bjorn H. (2016) How not to move the line drawn on pain. Animal Sentience 3(40)

Safina, Carl (2016) Fish pain: A painful topic. Animal Sentience 3(41)

Bowers, Robert Ian (2016) Devaluation as a strategy to address behaviourally whether fish feel. Animal Sentience 3(43)

Key, Brian (2016) Burden of proof lies with proposer of celestial teapot hypothesis. Animal Sentience 3(44)

Safina, Carl (2016) Fish pain's burden of proof. Animal Sentience 3(45)

Merker, Bjorn H. (2016) The line drawn on pain still holds. Animal Sentience 3(46)

Holmes, Tim Q. (2020) Impact of UK sport fishing on fish welfare and conservation. Animal Sentience 3(47)