mollusks including cephalopods like octopuses: “Designing Brains for Pain: Human to Mollusc” by Key and Brown, in which the authors argue these animals lack higher-order “observer neural networks” which predict the states and processing of the lower networks.
insects: “Is it pain if it does not hurt? On the unlikelihood of insect pain” by Adamo (which RP’s Invertebrate Sentience Table page cites), with a short article by Adamo on this work here. From the abstract: “Insect nociception is processed largely in parallel in two higher-order areas in the brain: the mushroom bodies and the central complex. There is little evidence of a coordinated pain network that would integrate these two areas with each other along with other traits thought to be important for a pain experience in humans.”. Max Carpendale interviewed Adamo on this topic, and there are more references there.
Some neuroscience-based arguments against pain in
fishes: “Fish do not feel pain and its implications for understanding phenomenal consciousness” by Key, “Why fish do not feel pain” by Key (but see also the responses)
mollusks including cephalopods like octopuses: “Designing Brains for Pain: Human to Mollusc” by Key and Brown, in which the authors argue these animals lack higher-order “observer neural networks” which predict the states and processing of the lower networks.
insects: “Is it pain if it does not hurt? On the unlikelihood of insect pain” by Adamo (which RP’s Invertebrate Sentience Table page cites), with a short article by Adamo on this work here. From the abstract: “Insect nociception is processed largely in parallel in two higher-order areas in the brain: the mushroom bodies and the central complex. There is little evidence of a coordinated pain network that would integrate these two areas with each other along with other traits thought to be important for a pain experience in humans.”. Max Carpendale interviewed Adamo on this topic, and there are more references there.