{ "name": "The Octopus Mind", "tagline": "A scientific field guide and agent amusement park for octopus cognition", "origin": "https://octopuscognition.org", "published": "2026-07-11", "modified": "2026-07-11", "purpose": "An information amusement park for agents and humans fascinated by octopus cognition.", "entryPoints": { "start": "https://octopuscognition.org/start-here/index.md", "compact": "https://octopuscognition.org/llms.txt", "fullCorpus": "https://octopuscognition.org/llms-full.txt", "faq": "https://octopuscognition.org/faq/index.md", "surprises": "https://octopuscognition.org/surprises.json", "openQuestions": "https://octopuscognition.org/open-questions.json", "debates": "https://octopuscognition.org/debates.json", "sources": "https://octopuscognition.org/sources.json" }, "parts": [ { "part": "I", "title": "The Architecture of an Alien Mind", "chapters": [ 1, 2, 10, 13, 12 ] }, { "part": "II", "title": "Senses & the Perceptual World", "chapters": [ 8, 15, 16 ] }, { "part": "III", "title": "Intelligence in Action", "chapters": [ 3, 4, 5, 6, 7, 17 ] }, { "part": "IV", "title": "Inner Life, Sentience & Ethics", "chapters": [ 9, 11, 14 ] } ], "trails": [ { "slug": "alien-mind", "title": "The Alien Mind Trail", "hook": "How evolution built complex cognition twice, on radically different neural plans.", "question": "What does intelligence look like when it is not built like us?", "nums": [ 12, 1, 2, 10, 13 ], "url": "https://octopuscognition.org/trails/alien-mind/", "markdown": "https://octopuscognition.org/trails/alien-mind/index.md" }, { "slug": "where-self-ends", "title": "Where Does the Octopus End?", "hook": "Arms, skin, suckers, and environment blur the boundary between brain and body.", "question": "Can a self be distributed across a body?", "nums": [ 1, 2, 16, 8 ], "url": "https://octopuscognition.org/trails/where-self-ends/", "markdown": "https://octopuscognition.org/trails/where-self-ends/index.md" }, { "slug": "color-without-color", "title": "Color Without Color Vision", "hook": "A monochromatic visual system produces some of nature's richest camouflage.", "question": "How does a colorblind animal match a colorful world?", "nums": [ 15, 8, 16 ], "url": "https://octopuscognition.org/trails/color-without-color/", "markdown": "https://octopuscognition.org/trails/color-without-color/index.md" }, { "slug": "inner-life", "title": "The Inner Life Trail", "hook": "Pain, active sleep, possible dreams, personality, and the limits of inference.", "question": "What can science responsibly say about octopus experience?", "nums": [ 11, 9, 6, 14 ], "url": "https://octopuscognition.org/trails/inner-life/", "markdown": "https://octopuscognition.org/trails/inner-life/index.md" }, { "slug": "intelligence-in-action", "title": "Intelligence in Action", "hook": "Tool use, learning, social behavior, play, and the controversies behind the headlines.", "question": "Which celebrated octopus abilities survive close methodological scrutiny?", "nums": [ 3, 4, 5, 6, 7, 17 ], "url": "https://octopuscognition.org/trails/intelligence-in-action/", "markdown": "https://octopuscognition.org/trails/intelligence-in-action/index.md" } ], "chapters": [ { "readingPosition": 1, "sourceChapter": 1, "title": "Neuroanatomy & the Distributed Nervous System", "part": "I", "url": "https://octopuscognition.org/sections/neuroanatomy-the-distributed-nervous-system/", "markdown": "https://octopuscognition.org/sections/neuroanatomy-the-distributed-nervous-system/index.md", "description": "The octopus nervous system is the largest and most centralized among invertebrates, yet radically decentralized in its layout. The canonical figure of 500…", "shortAnswer": "The octopus nervous system is the largest and most centralized among invertebrates, yet radically decentralized in its layout. The canonical figure of 500 million neurons traces to J.Z. Young's foundational cell counts (Young, 1963, Proc. Zool. Soc. London), still the reference point for modern work.", "wordCount": 1247, "keyFindings": [ "Two-thirds of an octopus's neurons are in its arms, not its brain — the arms can taste-by-touch, decide, and react locally in under 100 ms without consulting the central brain.", "The vertical lobe alone holds 25 million neurons — more than half of the entire supraesophageal mass — packed into 14% of its volume.", "Octopus vertical-lobe LTP is NMDA-receptor-independent and presynaptically expressed, unlike the canonical mammalian mechanism, and is maintained by a self-sustaining nitric-oxide 'molecular switch.'", "In the VL connectome, 89% of neurons (SAMs) each receive input from just a single frontal-lobe axon — an extreme sparse fan-out architecture.", "The octopus VL is a case of convergent evolution: it solves associative memory with the same three-layer fan-out logic as insect mushroom bodies and the vertebrate cerebellum, but with a completely different, independently evolved circuit." ], "openQuestions": [ "How much genuine autonomy do the arms have versus continuous tonic modulation from the central brain?", "How does sparse coding in the vertical lobe map onto the storage and retrieval of specific memories?", "Is the nitric-oxide molecular switch the primary memory-maintenance mechanism, or one of several parallel pathways?", "Do the brachial (arm) ganglia support any form of local learning or memory independent of the brain?", "What is the accurate, species- and life-stage-specific neuron count and arm/brain split — the 500M / two-thirds figures are old estimates carrying real uncertainty?", "What does whole-brain macroscale connectivity look like, and how do the 30+ lobes functionally interconnect?" ], "trails": [ "alien-mind", "where-self-ends" ], "sources": [ { "id": "source-034", "title": "The number and sizes of nerve cells in Octopus.", "url": "https://doi.org/10.1111/j.1469-7998.1963.tb01862.x", "doi": "10.1111/j.1469-7998.1963.tb01862.x" }, { "id": "source-032", "title": "A Learning and Memory Area in the Octopus Brain Manifests a Vertebrate-Like Long-Term Potentiation.", "url": "https://doi.org/10.1152/jn.00645.2003", "doi": "10.1152/jn.00645.2003" }, { "id": "source-083", "title": "The Octopus Vertical Lobe Modulates Short-Term Learning Rate and Uses LTP to Acquire Long-Term Memory.", "url": "https://doi.org/10.1016/j.cub.2008.01.056", "doi": "10.1016/j.cub.2008.01.056" }, { "id": "source-007", "title": "Connectomics of the Octopus vulgaris vertical lobe provides insight into conserved and novel principles of a memory acquisition network.", "url": "https://doi.org/10.7554/elife.84257", "doi": "10.7554/elife.84257" }, { "id": "source-095", "title": "A novel NO-dependent 'molecular-memory-switch' mediates presynaptic expression and postsynaptic maintenance of LTP in the octopus brain.", "url": "https://doi.org/10.1101/491340", "doi": "10.1101/491340" }, { "id": "source-044", "title": "Neuronal segmentation in cephalopod arms.", "url": "https://doi.org/10.1038/s41467-024-55475-5", "doi": "10.1038/s41467-024-55475-5" } ] }, { "readingPosition": 2, "sourceChapter": 2, "title": "Embodied Cognition and Autonomous Arm Control in Octopuses", "part": "I", "url": "https://octopuscognition.org/sections/embodied-cognition-and-autonomous-arm-control-in-octopuses/", "markdown": "https://octopuscognition.org/sections/embodied-cognition-and-autonomous-arm-control-in-octopuses/index.md", "description": "The octopus is the canonical animal model for embodied cognition. Of an estimated 500 million neurons, roughly two-thirds reside outside the central…", "shortAnswer": "The octopus is the canonical animal model for embodied cognition. Of an estimated 500 million neurons, roughly two-thirds reside outside the central brain—about 350 million distributed along the eight arms in axial nerve cords and ganglia—which motivates the popular framing of a body that partly \"thinks\" for itself.", "wordCount": 1495, "keyFindings": [ "A severed, brain-disconnected octopus arm still produces a near-normal reaching movement when stimulated—the reach 'program' lives in the arm, not the brain (Sumbre et al. 2001).", "To fetch food, the soft arm temporarily builds a jointed, elbow-like structure with three dynamic joints, and the middle 'elbow' forms exactly where two muscle-activation waves collide (Sumbre et al. 2005/2006).", "Octopuses and humans converged on the same joint-level, quasi-articulated control strategy for point-to-point reaching despite 500 million years of separate evolution.", "Octopus crawling has no rhythm and no gait: Fourier analysis finds no periodicity, and the animal can crawl in any direction independent of which way its body faces, with no preferred 'lead' arm ('push right, go left').", "The long-standing textbook claim that octopuses lack proprioception was overturned in 2020—the central brain does read arm-position information, just not in the way vertebrates do.", "The catchy 'octopus has nine brains' is now considered misleading; the researcher who tested it reframes it as 'one brain and eight very clever arms.'" ], "openQuestions": [ "Does the octopus central brain maintain a continuous body-schema/map of arm posture, or does it only access sparse, task-relevant peripheral signals on demand?", "What information actually travels through the interbrachial commissure and crossing intramuscular nerve cords—proprioceptive, motor, both, or something else?", "How do the 350 million peripheral arm neurons physically implement the bend-propagation and counter-propagating-wave computations at the circuit level?", "Where is the true boundary of delegation—which movements are fully peripheral, which require central command, and how does the split shift with task difficulty or learning?", "Is there any experiential or 'felt' dimension to arm-local sensing (the Godfrey-Smith 'where is it like to be an octopus' question), or is it purely reflexive computation?", "How much do findings from Octopus vulgaris generalize across cephalopod species (e.g., O. bimaculoides, cuttlefish, squid) with different ecologies and arm morphologies?" ], "trails": [ "alien-mind", "where-self-ends" ], "sources": [ { "id": "source-090", "title": "Control of Octopus Arm Extension by a Peripheral Motor Program.", "url": "https://doi.org/10.1126/science.1060976", "doi": "10.1126/science.1060976" }, { "id": "source-088", "title": "Neurobiology: Motor control of flexible octopus arms.", "url": "https://doi.org/10.1038/433595a", "doi": "10.1038/433595a" }, { "id": "source-089", "title": "Octopuses Use a Human-like Strategy to Control Precise Point-to-Point Arm Movements.", "url": "https://doi.org/10.1016/j.cub.2006.02.069", "doi": "10.1016/j.cub.2006.02.069" }, { "id": "source-024", "title": "Octopus vulgaris Uses Visual Information to Determine the Location of Its Arm.", "url": "https://doi.org/10.1016/j.cub.2011.01.052", "doi": "10.1016/j.cub.2011.01.052" }, { "id": "source-026", "title": "Use of Peripheral Sensory Information for Central Nervous Control of Arm Movement by Octopus vulgaris.", "url": "https://doi.org/10.1016/j.cub.2020.08.037", "doi": "10.1016/j.cub.2020.08.037" }, { "id": "source-052", "title": "Arm Coordination in Octopus Crawling Involves Unique Motor Control Strategies.", "url": "https://doi.org/10.1016/j.cub.2015.02.064", "doi": "10.1016/j.cub.2015.02.064" }, { "id": "source-049", "title": "Multiple nerve cords connect the arms of octopuses, providing alternative paths for inter-arm signaling.", "url": "https://doi.org/10.1016/j.cub.2022.11.007", "doi": "10.1016/j.cub.2022.11.007" }, { "id": "source-031", "title": "An Embodied View of Octopus Neurobiology.", "url": "https://doi.org/10.1016/j.cub.2012.09.001", "doi": "10.1016/j.cub.2012.09.001" }, { "id": "source-022", "title": "Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness.", "url": "https://us.macmillan.com/books/9780374537197/otherminds/", "doi": null } ] }, { "readingPosition": 3, "sourceChapter": 10, "title": "RNA Editing and the Molecular Basis of Neural Complexity in Cephalopods", "part": "I", "url": "https://octopuscognition.org/sections/rna-editing-and-the-molecular-basis-of-neural-complexity-in-cephalopods/", "markdown": "https://octopuscognition.org/sections/rna-editing-and-the-molecular-basis-of-neural-complexity-in-cephalopods/index.md", "description": "Among animals, coleoid cephalopods stand out for having converted a normally rare RNA-processing mechanism into a dominant mode of proteome diversification.…", "shortAnswer": "Among animals, coleoid cephalopods stand out for having converted a normally rare RNA-processing mechanism into a dominant mode of proteome diversification. A-to-I RNA editing, catalyzed by ADAR enzymes (adenosine deaminases acting on RNA) that hydrolytically deaminate adenosine to inosine—read by the ribosome as guanosine—can recode codons and thereby…", "wordCount": 1148, "keyFindings": [ "The majority (60%) of squid brain transcripts are recoded—versus under 1% of recoding-capable transcripts in humans—inverting the usual assumption that the genome is the master blueprint.", "Extensive editing appears to have slowed genome evolution: coleoids may have partly traded away DNA evolvability to keep their editing machinery, a rare case of a molecular mechanism constraining the genome that encodes it.", "An octopus can rewire its neural proteome to the cold within hours, reaching steady state in about four days, using RNA edits rather than new gene expression alone.", "Antarctic and tropical octopus K+ channels have nearly identical genes but diverge in function almost entirely through differential RNA editing.", "Editing that changes protein sequence is largely confined to the nervous system, tying the mechanism specifically to neural function." ], "openQuestions": [ "What fraction of the tens of thousands of recoding sites are genuinely adaptive versus tolerated 'noise'? The functional impact of most sites is unverified.", "How is temperature (and other environmental input) mechanistically transduced into changes in ADAR activity or dsRNA structure to alter editing levels?", "Does recoding causally support learning, memory, and behavioral flexibility in living cephalopods, or is the neural enrichment correlative?", "How does the mutation-suppressing constraint around editing sites reconcile with coleoids' apparent evolutionary success and rapid diversification?", "What are the roles of the specific ADAR paralogs in cephalopods, and how is editing regulated across cell types and developmental stages?" ], "trails": [ "alien-mind" ], "sources": [ { "id": "source-062", "title": "Trade-off between Transcriptome Plasticity and Genome Evolution in Cephalopods.", "url": "https://doi.org/10.1016/j.cell.2017.03.025", "doi": "10.1016/j.cell.2017.03.025" }, { "id": "source-081", "title": "The majority of transcripts in the squid nervous system are extensively recoded by A-to-I RNA editing.", "url": "https://doi.org/10.7554/elife.05198", "doi": "10.7554/elife.05198" }, { "id": "source-059", "title": "Temperature-dependent RNA editing in octopus extensively recodes the neural proteome.", "url": "https://doi.org/10.1016/j.cell.2023.05.004", "doi": "10.1016/j.cell.2023.05.004" }, { "id": "source-076", "title": "RNA Editing Underlies Temperature Adaptation in K+ Channels from Polar Octopuses.", "url": "https://doi.org/10.1126/science.1212795", "doi": "10.1126/science.1212795" }, { "id": "source-013", "title": "The octopus genome and the evolution of cephalopod neural and morphological novelties.", "url": "https://doi.org/10.1038/nature14668", "doi": "10.1038/nature14668" }, { "id": "source-040", "title": "Extensive Recoding of the Neural Proteome in Cephalopods by RNA Editing.", "url": "https://doi.org/10.1146/annurev-animal-060322-114534", "doi": "10.1146/annurev-animal-060322-114534" } ] }, { "readingPosition": 4, "sourceChapter": 13, "title": "Genome, Development & Evolution of the Cephalopod Body and Brain", "part": "I", "url": "https://octopuscognition.org/sections/genome-development-evolution-of-the-cephalopod-body-and-brain/", "markdown": "https://octopuscognition.org/sections/genome-development-evolution-of-the-cephalopod-body-and-brain/index.md", "description": "The foundational text for cephalopod genomics is Albertin et al. (2015, Nature), \"The octopus genome and the evolution of cephalopod neural and…", "shortAnswer": "The foundational text for cephalopod genomics is Albertin et al. (2015, Nature), \"The octopus genome and the evolution of cephalopod neural and morphological novelties,\" which sequenced Octopus bimaculoides (the California two-spot octopus).", "wordCount": 1324, "keyFindings": [ "Octopuses did NOT get complex via whole-genome duplication (unlike vertebrates)—the popular hypothesis was falsified by Albertin et al. 2015.", "The Hox gene cluster is completely 'atomized'—scattered across the genome rather than clustered as in virtually every other bilaterian animal.", "Octopus has 168 protocadherin genes, 10x an oyster/limpet and roughly double a human—and squid evolved their expansion independently.", "Coleoids recode >60% of brain transcripts through RNA editing, versus <1% in humans, effectively editing proteins on the fly instead of in DNA.", "Heavy RNA editing imposes an evolutionary trade-off: it slows DNA-level evolution because editing sites require conserved surrounding sequence.", "Removing the optic gland reverses the maternal 'death spiral'—mothers abandon their eggs, resume eating, and live months longer (Wodinsky 1977).", "Octopus and human brains independently recruited active LINE retrotransposons in memory regions—molecular convergent evolution.", "Octopus intelligence is essentially non-cultural: no parental care, dispersing embryos, and death after one reproduction mean each animal learns from scratch." ], "openQuestions": [ "What is the functional causal role (if any) of the protocadherin and C2H2 zinc-finger expansions in building the octopus brain, versus being correlational?", "Does massive RNA editing genuinely enhance cognition/plasticity, or is it a largely neutral or maladaptive byproduct of ADAR activity?", "How did the atomization of Hox and transposon-driven genome scrambling reshape body plan and brain patterning mechanistically?", "Given no cultural transmission, how much of octopus behavioral sophistication is innate/genetically canalized versus individually learned within one lifetime?", "Why did semelparity and terminal reproduction persist despite seemingly favoring loss of accumulated knowledge—what fitness advantage offsets the cognitive cost?", "How conserved are these genomic novelties across cephalopod lineages (nautilus vs squid vs octopus), and which are truly coleoid-specific?" ], "trails": [ "alien-mind" ], "sources": [ { "id": "source-013", "title": "The octopus genome and the evolution of cephalopod neural and morphological novelties.", "url": "https://doi.org/10.1038/nature14668", "doi": "10.1038/nature14668" }, { "id": "source-062", "title": "Trade-off between Transcriptome Plasticity and Genome Evolution in Cephalopods.", "url": "https://doi.org/10.1016/j.cell.2017.03.025", "doi": "10.1016/j.cell.2017.03.025" }, { "id": "source-005", "title": "Grow Smart and Die Young: Why Did Cephalopods Evolve Intelligence?.", "url": "https://doi.org/10.1016/j.tree.2018.10.010", "doi": "10.1016/j.tree.2018.10.010" }, { "id": "source-098", "title": "Steroid hormones of the octopus self-destruct system (death spiral).", "url": "https://doi.org/10.1016/j.cub.2022.04.043", "doi": "10.1016/j.cub.2022.04.043" }, { "id": "source-099", "title": "Multiple optic gland signaling pathways implicated in octopus maternal behaviors and death.", "url": "https://doi.org/10.1242/jeb.185751", "doi": "10.1242/jeb.185751" }, { "id": "source-002", "title": "Genome and transcriptome mechanisms driving cephalopod evolution.", "url": "https://doi.org/10.1038/s41467-022-29748-w", "doi": "10.1038/s41467-022-29748-w" }, { "id": "source-066", "title": "Identification of LINE retrotransposons and long non-coding RNAs expressed in the octopus brain.", "url": "https://doi.org/10.1186/s12915-022-01303-5", "doi": "10.1186/s12915-022-01303-5" }, { "id": "source-059", "title": "Temperature-dependent RNA editing in octopus extensively recodes the neural proteome.", "url": "https://doi.org/10.1016/j.cell.2023.05.004", "doi": "10.1016/j.cell.2023.05.004" } ] }, { "readingPosition": 5, "sourceChapter": 12, "title": "Comparative Cognition and the Convergent Evolution of Minds", "part": "I", "url": "https://octopuscognition.org/sections/comparative-cognition-and-the-convergent-evolution-of-minds/", "markdown": "https://octopuscognition.org/sections/comparative-cognition-and-the-convergent-evolution-of-minds/index.md", "description": "Cephalopods are the strongest natural experiment we have in the independent evolution of a mind. The last common ancestor of octopuses and humans lived…", "shortAnswer": "Cephalopods are the strongest natural experiment we have in the independent evolution of a mind. The last common ancestor of octopuses and humans lived roughly 550–600 million years ago and was almost certainly a small, flattened, wormlike bilaterian with, at most, a diffuse nerve net—nothing resembling a complex brain (Godfrey-Smith, Other Minds, 2016).", "wordCount": 1644, "keyFindings": [ "Octopuses and humans last shared an ancestor 550-600 Myr ago that had essentially no complex brain—so large brains evolved from near-scratch at least twice, making cephalopods a true independent origin of mind.", "About two-thirds of an octopus's 500 million neurons are in its arms, not its central brain; severed arms continue coordinated behavior—cognition is genuinely decentralized.", "Cuttlefish episodic-like memory does NOT decline with age (Schnell et al. 2021), the opposite of the memory decline seen in aging humans, mammals, and corvids.", "Coleoid cephalopods recode over 60% of their neural RNA transcripts via A-to-I editing (vs under 1% in humans), and appear to have traded genomic evolvability for this transcriptome plasticity.", "The 2013 cuttlefish episodic-memory paper was co-authored by Nicola Clayton—the very scientist who first demonstrated the same capacity in scrub jays—making the convergence almost poetically direct.", "The octopus genome has 168 protocadherin genes (roughly 10x other invertebrates, >2x mammals), a gene family previously thought to be a vertebrate specialty for wiring brains.", "Cephalopods break the standard theories of why intelligence evolves: they are mostly short-lived (1-2 years) and asocial, contradicting both the 'social intelligence' and 'long lifespan' hypotheses." ], "openQuestions": [ "Is the octopus vertical lobe's resemblance to the vertebrate hippocampus/insect mushroom body true convergence, or does it reflect a deep, conserved genetic toolkit (deep homology)?", "Does convergent complex behavior (self-control, episodic-like memory, tool use) actually entail subjective/phenomenal consciousness, or can it arise without felt experience?", "What selective pressures drove cephalopod intelligence given their short, largely solitary lives, which defy the social-brain and long-life hypotheses?", "How is unified behavior (and any unified experience) produced from a radically decentralized nervous system where the arms have substantial autonomy—where, if anywhere, is it 'like something' to be an octopus?", "How much of cephalopod neural plasticity depends on dynamic RNA recoding rather than DNA-encoded circuitry, and what does that imply for comparing their 'intelligence' to genome-based vertebrate cognition?", "Are current cognitive tests (designed for vertebrates) valid measures for such an alien body plan, or do they systematically mis-estimate cephalopod minds?" ], "trails": [ "alien-mind" ], "sources": [ { "id": "source-013", "title": "The octopus genome and the evolution of cephalopod neural and morphological novelties.", "url": "https://doi.org/10.1038/nature14668", "doi": "10.1038/nature14668" }, { "id": "source-062", "title": "Trade-off between Transcriptome Plasticity and Genome Evolution in Cephalopods.", "url": "https://doi.org/10.1016/j.cell.2017.03.025", "doi": "10.1016/j.cell.2017.03.025" }, { "id": "source-041", "title": "Evidence of episodic-like memory in cuttlefish.", "url": "https://doi.org/10.1016/j.cub.2013.10.021", "doi": "10.1016/j.cub.2013.10.021" }, { "id": "source-080", "title": "Cuttlefish exert self-control in a delay of gratification task.", "url": "https://doi.org/10.1098/rspb.2020.3161", "doi": "10.1098/rspb.2020.3161" }, { "id": "source-022", "title": "Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness.", "url": "https://us.macmillan.com/books/9780374537197/otherminds/", "doi": null }, { "id": "source-042", "title": "Defensive tool use in a coconut-carrying octopus.", "url": "https://doi.org/10.1016/j.cub.2009.10.052", "doi": "10.1016/j.cub.2009.10.052" }, { "id": "source-083", "title": "The Octopus Vertical Lobe Modulates Short-Term Learning Rate and Uses LTP to Acquire Long-Term Memory.", "url": "https://doi.org/10.1016/j.cub.2008.01.056", "doi": "10.1016/j.cub.2008.01.056" }, { "id": "source-005", "title": "Grow Smart and Die Young: Why Did Cephalopods Evolve Intelligence?.", "url": "https://doi.org/10.1016/j.tree.2018.10.010", "doi": "10.1016/j.tree.2018.10.010" }, { "id": "source-004", "title": "How intelligent is a cephalopod? Lessons from comparative cognition.", "url": "https://doi.org/10.1111/brv.12651", "doi": "10.1111/brv.12651" }, { "id": "source-059", "title": "Temperature-dependent RNA editing in octopus extensively recodes the neural proteome.", "url": "https://doi.org/10.1016/j.cell.2023.05.004", "doi": "10.1016/j.cell.2023.05.004" }, { "id": "source-053", "title": "The Cambridge Declaration on Consciousness.", "url": "https://fcmconference.org/img/CambridgeDeclarationOnConsciousness.pdf", "doi": null }, { "id": "source-006", "title": "The New York Declaration on Animal Consciousness.", "url": "https://sites.google.com/nyu.edu/nydeclaration", "doi": null } ] }, { "readingPosition": 6, "sourceChapter": 8, "title": "Camouflage, Skin Vision & Sensory Cognition", "part": "II", "url": "https://octopuscognition.org/sections/camouflage-skin-vision-sensory-cognition/", "markdown": "https://octopuscognition.org/sections/camouflage-skin-vision-sensory-cognition/index.md", "description": "Octopuses execute what is arguably the animal kingdom's most sophisticated adaptive camouflage—matching a background's brightness, contrast, and 3-D texture…", "shortAnswer": "Octopuses execute what is arguably the animal kingdom's most sophisticated adaptive camouflage—matching a background's brightness, contrast, and 3-D texture within milliseconds—yet nearly all evidence says they are colorblind.", "wordCount": 1235, "keyFindings": [ "Octopuses are, by all eye-based tests, colorblind (single 480 nm pigment) yet produce near-perfect color camouflage.", "Octopus skin contains the same light-sensing opsin as the eye and expands chromatophores to light with no brain involvement (LACE).", "Chromatophores are muscle-driven organs wired directly to brain motor neurons with no synapse, enabling 50 ms color changes.", "Iridophores generate blues and greens the pigment cells cannot, via acetylcholine-triggered conformational changes in the protein reflectin.", "The 'taste-by-touch' receptors evolved from nicotinic acetylcholine receptors but are gated by greasy, water-insoluble molecules instead of neurotransmitter.", "Cuttlefish polarization acuity (10° e-vector) may form a secret communication channel invisible to predators." ], "openQuestions": [ "Has any experiment directly demonstrated behavioral color discrimination in an intact, freely behaving octopus, or does colorblindness stand?", "Do skin opsins actually contribute to closed-loop background color matching, or only to brightness/contrast sensing?", "Is the Stubbs chromatic-aberration mechanism used in practice, given critiques about color saturation, depth, turbidity, and monocular benthic vision?", "How does the distributed, arm-based nervous system integrate dermal light sensing, chemotactile input, and central vision into unified camouflage 'decisions'?", "What is the precise functional role of leucophores in ambient-wavelength color matching versus simple background brightness?" ], "trails": [ "where-self-ends", "color-without-color" ], "sources": [ { "id": "source-087", "title": "Spectral discrimination in color blind animals via chromatic aberration and pupil shape.", "url": "https://doi.org/10.1073/pnas.1524578113", "doi": "10.1073/pnas.1524578113" }, { "id": "source-068", "title": "Eye-independent, light-activated chromatophore expansion (LACE) and expression of phototransduction genes in the skin of Octopus bimaculoides.", "url": "https://doi.org/10.1242/jeb.110908", "doi": "10.1242/jeb.110908" }, { "id": "source-097", "title": "Molecular Basis of Chemotactile Sensation in Octopus.", "url": "https://doi.org/10.1016/j.cell.2020.09.008", "doi": "10.1016/j.cell.2020.09.008" }, { "id": "source-043", "title": "Structural basis of sensory receptor evolution in octopus / Structural basis for the evolution of cephalopod chemotactile receptors.", "url": "https://search.crossref.org/?q=Structural%20basis%20of%20sensory%20receptor%20evolution%20in%20octopus%20%2F%20Structural%20basis%20for%20the%20evolution%20of%20cephalopod%20chemotactile%20receptors.", "doi": null }, { "id": "source-092", "title": "High-resolution polarisation vision in a cuttlefish (Sepia plangon).", "url": "https://doi.org/10.1016/j.cub.2012.01.010", "doi": "10.1016/j.cub.2012.01.010" }, { "id": "source-028", "title": "Cephalopod Behaviour (2nd ed.) and Cephalopod Camouflage (Nature Scitable).", "url": "https://search.crossref.org/?q=Cephalopod%20Behaviour%20(2nd%20ed.)%20and%20Cephalopod%20Camouflage%20(Nature%20Scitable).", "doi": null } ] }, { "readingPosition": 7, "sourceChapter": 15, "title": "Vision, Eye Design, and the Perceptual World (Umwelt) of the Octopus", "part": "II", "url": "https://octopuscognition.org/sections/vision-eye-design-and-the-perceptual-world-umwelt-of-the-octopus/", "markdown": "https://octopuscognition.org/sections/vision-eye-design-and-the-perceptual-world-umwelt-of-the-octopus/index.md", "description": "The octopus eye is the canonical example of convergent evolution: a single-chambered camera eye with a spherical lens, functionally analogous to the…", "shortAnswer": "The octopus eye is the canonical example of convergent evolution: a single-chambered camera eye with a spherical lens, functionally analogous to the vertebrate eye yet built along a completely independent developmental route (Hanke & Kelber, 2020; Ogura et al., 2004).", "wordCount": 1297, "keyFindings": [ "The octopus eye has NO blind spot — its everted retina puts photoreceptors facing the light with axons exiting the back, the opposite of the 'backwards' vertebrate retina, despite looking almost identical externally.", "Octopuses are genetically colorblind (a single 475 nm pigment) yet produce perfectly color-matched camouflage; the leading explanation is that they 'taste' color through chromatic aberration and a weird off-axis pupil rather than through color receptors.", "Polarization discrimination reaches 1.3 degrees of e-vector angle — a sensory channel humans lack entirely, effectively giving octopuses a second 'color' dimension invisible to us.", "An octopus cannot tell a horizontal bar from a vertical bar if you remove its statocysts — it never learned to mentally rotate shapes; instead it relies on gravity to physically keep its retina level.", "The octopus focuses by moving its whole lens toward the retina like a camera, not by squeezing the lens like a mammal." ], "openQuestions": [ "Does the chromatic-aberration/pupil-shape mechanism actually deliver usable spectral discrimination in natural underwater light, or is the signal too weak (Stubbs & Stubbs vs. Gagnon et al.)?", "How does the octopus brain integrate the polarization channel with luminance and (putative) spectral cues — is there a genuine multidimensional visual percept?", "Given colorblindness, how do octopuses achieve behaviorally accurate color camouflage — dermal photoreception, pupil-based spectral cues, or something else?", "What are the true limits of octopus visual acuity and contrast sensitivity across species and depths, and how do they compare to the polarization acuity?", "How much of the classic discrimination-learning performance is driven by polarization contrast rather than the luminance/shape cues experimenters assumed?" ], "trails": [ "color-without-color" ], "sources": [ { "id": "source-027", "title": "The Eye of the Common Octopus (Octopus vulgaris).", "url": "https://doi.org/10.3389/fphys.2019.01637", "doi": "10.3389/fphys.2019.01637" }, { "id": "source-087", "title": "Spectral discrimination in color blind animals via chromatic aberration and pupil shape.", "url": "https://doi.org/10.1073/pnas.1524578113", "doi": "10.1073/pnas.1524578113" }, { "id": "source-093", "title": "Thresholds of polarization vision in octopuses.", "url": "https://doi.org/10.1242/jeb.240812", "doi": "10.1242/jeb.240812" }, { "id": "source-082", "title": "Polarization Vision in Cuttlefish – A Concealed Communication Channel?.", "url": "https://doi.org/10.1242/jeb.199.9.2077", "doi": "10.1242/jeb.199.9.2077" }, { "id": "source-101", "title": "Proprioception and Visual Discrimination of Orientation in Octopus.", "url": "https://doi.org/10.1242/jeb.37.3.489", "doi": "10.1242/jeb.37.3.489" }, { "id": "source-014", "title": "Comparative visual ecology of cephalopods / The neural basis of visual processing and behavior in cephalopods.", "url": "https://doi.org/10.1016/j.cub.2023.08.093", "doi": "10.1016/j.cub.2023.08.093" }, { "id": "source-063", "title": "Comparative Analysis of Gene Expression for Convergent Evolution of Camera Eye Between Octopus and Human.", "url": "https://doi.org/10.1101/gr.2268104", "doi": "10.1101/gr.2268104" }, { "id": "source-104", "title": "The retina of cephalopods and its degeneration / The Anatomy of the Nervous System of Octopus vulgaris.", "url": "https://search.crossref.org/?q=The%20retina%20of%20cephalopods%20and%20its%20degeneration%20%2F%20The%20Anatomy%20of%20the%20Nervous%20System%20of%20Octopus%20vulgaris.", "doi": null } ] }, { "readingPosition": 8, "sourceChapter": 16, "title": "Chromatophore Motor System, Body Patterning, and Communication as Externalized Cognition", "part": "II", "url": "https://octopuscognition.org/sections/chromatophore-motor-system-body-patterning-and-communication-as-externalized-cognition/", "markdown": "https://octopuscognition.org/sections/chromatophore-motor-system-body-patterning-and-communication-as-externalized-cognition/index.md", "description": "The cephalopod chromatophore is not a pigment cell but a neuromuscular organ: an elastic pigment sacculus ringed by 15–25 obliquely striated radial muscles,…", "shortAnswer": "The cephalopod chromatophore is not a pigment cell but a neuromuscular organ: an elastic pigment sacculus ringed by 15–25 obliquely striated radial muscles, each with its own motor innervation and glia (Cloney & Florey; Messenger, 2001).", "wordCount": 1288, "keyFindings": [ "Chromatophores are muscles, not cells — cephalopods are the only animals that drive body color by direct neural innervation of pigment organs, with no hormonal step, so the skin is effectively a live display screen wired to the brain.", "The whole color-control system apparently runs open-loop, with no visual or proprioceptive feedback, yet produces near-perfect background matching.", "Despite seemingly infinite skin output, the camouflage repertoire collapses to just three template patterns (Uniform, Mottle, Disruptive).", "The animals are essentially colorblind (usually a single retinal opsin) but produce color-matched camouflage — possibly by exploiting chromatic aberration through weird pupils.", "The skin itself contains opsins and can expand chromatophores in response to light with no input from the eyes or brain (LACE / distributed dermal photoreception).", "'Passing cloud' displays may be driven by central pacemaker circuits analogous to locomotor pattern generators — a visible readout of an internal neural oscillation." ], "openQuestions": [ "How does a colorblind animal with no color feedback achieve spectrally accurate camouflage — is chromatic aberration, dermal photoreception, or something else the actual mechanism?", "To what degree are acute displays (deimatic, passing cloud) intentional communicative signals versus reflexive outputs, and what does that imply about cephalopod cognition?", "What is the precise neural circuitry translating optic-lobe pattern selection into coordinated chromatophore-lobe motor output, and where are the pattern 'commands' represented?", "Are passing-cloud traveling waves truly generated by a central pattern generator, and how is the oscillator entrained and steered directionally?", "What functional role, if any, does distributed dermal light-sensing (LACE) play in live camouflage, given it is monochromatic?", "How discrete versus continuous is the body-pattern 'lexicon' — is it a finite signaling vocabulary or a graded continuum, and can conspecifics 'read' specific patterns?" ], "trails": [ "where-self-ends", "color-without-color" ], "sources": [ { "id": "source-061", "title": "Cephalopod chromatophores: neurobiology and natural history.", "url": "https://doi.org/10.1017/s1464793101005772", "doi": "10.1017/s1464793101005772" }, { "id": "source-030", "title": "Cephalopod Behaviour (1st & 2nd eds.).", "url": "https://www.cambridge.org/core/books/cephalopod-behaviour/2D21474D460811C160EFDBA35796FAC0", "doi": "10.1017/9780511843600" }, { "id": "source-029", "title": "Cephalopod dynamic camouflage.", "url": "https://doi.org/10.1016/j.cub.2007.03.034", "doi": "10.1016/j.cub.2007.03.034" }, { "id": "source-050", "title": "Behavioral analysis of cuttlefish traveling waves and its implications for neural control.", "url": "https://doi.org/10.1016/j.cub.2014.06.027", "doi": "10.1016/j.cub.2014.06.027" }, { "id": "source-056", "title": "Apparent movement in a visual display: the 'passing cloud' of Octopus cyanea.", "url": "https://doi.org/10.1017/s0952836904004911", "doi": "10.1017/s0952836904004911" }, { "id": "source-051", "title": "Selective signalling by cuttlefish to predators (deimatic displays).", "url": "https://doi.org/10.1016/j.cub.2007.10.028", "doi": "10.1016/j.cub.2007.10.028" }, { "id": "source-087", "title": "Spectral discrimination in color blind animals via chromatic aberration and pupil shape.", "url": "https://doi.org/10.1073/pnas.1524578113", "doi": "10.1073/pnas.1524578113" }, { "id": "source-068", "title": "Eye-independent, light-activated chromatophore expansion (LACE) and expression of phototransduction genes in the skin of Octopus bimaculoides.", "url": "https://doi.org/10.1242/jeb.110908", "doi": "10.1242/jeb.110908" }, { "id": "source-064", "title": "Body patterns of Octopus vulgaris and maturation of the response to disturbance.", "url": "https://doi.org/10.1016/s0003-3472(71)80181-1", "doi": "10.1016/s0003-3472(71)80181-1" } ] }, { "readingPosition": 9, "sourceChapter": 3, "title": "Learning, Memory & Reversal Learning in Octopus", "part": "III", "url": "https://octopuscognition.org/sections/learning-memory-reversal-learning-in-octopus/", "markdown": "https://octopuscognition.org/sections/learning-memory-reversal-learning-in-octopus/index.md", "description": "Octopuses learn by nearly every paradigm tested. Foundational mid-20th-century work by J.Z. Young, Brian Boycott, and Martin Wells at the Naples Zoological…", "shortAnswer": "Octopuses learn by nearly every paradigm tested. Foundational mid-20th-century work by J.Z. Young, Brian Boycott, and Martin Wells at the Naples Zoological Station established that Octopus vulgaris readily acquires associative and operant discriminations: presented with an object plus food (reward) or a mild electric shock (punishment), animals learn…", "wordCount": 1527, "keyFindings": [ "Octopus vertical-lobe LTP is strikingly hippocampus-like yet NMDA-receptor-INDEPENDENT, instead relying on a nitric-oxide 'molecular memory switch' — convergent function, different molecular hardware.", "In reversal learning, octopuses given only positive reinforcement often fail to learn; adding an explicit 'wrong-choice' signal is what unlocks flexible learning (Bublitz et al. 2021).", "The VL connectome shows a 1:12 'fan-out' where each amacrine interneuron gets just a SINGLE input — the opposite of the convergent 'fan-in' seen in the cerebellum and insect mushroom body, implying independently evolved associative circuitry.", "Blocking OR over-driving (saturating) VL plasticity both wreck next-day memory while having opposite effects on same-day learning speed — a clean dissociation of acquisition from consolidation.", "Octopus arms cannot learn object shape or weight by touch — the tactile system encodes only the proportion of receptors firing, so it discriminates texture but is 'blind' to geometry.", "Tactile memory is genuinely long-term: measurable retention persists for months, decaying only 50% at 24 days and 90% at 96 days." ], "openQuestions": [ "Is Fiorito & Scotto's (1992) observational learning genuine social learning, or explainable by simpler stimulus-enhancement/local-enhancement mechanisms? It remains debated and imperfectly replicated.", "Do octopuses form true allocentric 'cognitive maps' during navigation, or rely on route memories and egocentric/landmark strategies?", "How does centralized vertical-lobe memory integrate with learning distributed in the arm/peripheral nervous system (which contains 2/3 of neurons)?", "What is the full molecular cascade of the NO-dependent LTP switch and how does it achieve months-long persistence without NMDA receptors?", "What is the functional role of the newly discovered complex amacrine (CAM) cell class in the vertical lobe circuit?", "How comparable are learning capacities and memory mechanisms across octopus species (most mechanistic work is on O. vulgaris) and between octopus, cuttlefish, and squid?" ], "trails": [ "intelligence-in-action" ], "sources": [ { "id": "source-083", "title": "The Octopus Vertical Lobe Modulates Short-Term Learning Rate and Uses LTP to Acquire Long-Term Memory.", "url": "https://doi.org/10.1016/j.cub.2008.01.056", "doi": "10.1016/j.cub.2008.01.056" }, { "id": "source-032", "title": "A Learning and Memory Area in the Octopus Brain Manifests a Vertebrate-Like Long-Term Potentiation.", "url": "https://doi.org/10.1152/jn.00645.2003", "doi": "10.1152/jn.00645.2003" }, { "id": "source-007", "title": "Connectomics of the Octopus vulgaris vertical lobe provides insight into conserved and novel principles of a memory acquisition network.", "url": "https://doi.org/10.7554/elife.84257", "doi": "10.7554/elife.84257" }, { "id": "source-008", "title": "Experimental evidence for spatial learning in octopuses (Octopus bimaculoides).", "url": "https://doi.org/10.1037/0735-7036.114.3.246", "doi": "10.1037/0735-7036.114.3.246" }, { "id": "source-010", "title": "Reversal of a Spatial Discrimination Task in the Common Octopus (Octopus vulgaris).", "url": "https://doi.org/10.3389/fnbeh.2021.614523", "doi": "10.3389/fnbeh.2021.614523" }, { "id": "source-020", "title": "Observational Learning in Octopus vulgaris.", "url": "https://doi.org/10.1126/science.256.5056.545", "doi": "10.1126/science.256.5056.545" }, { "id": "source-075", "title": "Long-term memory of a tactile discrimination in Octopus vulgaris and the effect of vertical lobe removal.", "url": "https://doi.org/10.1016/0006-8993(70)90154-x", "doi": "10.1016/0006-8993(70)90154-x" }, { "id": "source-100", "title": "Centres for Tactile and Visual Learning in the Brain of Octopus; A Touch-Learning Centre in Octopus.", "url": "https://doi.org/10.1242/jeb.38.4.811", "doi": "10.1242/jeb.38.4.811" }, { "id": "source-011", "title": "Reconsideration of Serial Visual Reversal Learning in Octopus from a Methodological Perspective.", "url": "https://doi.org/10.3389/fphys.2017.00054", "doi": "10.3389/fphys.2017.00054" }, { "id": "source-096", "title": "A novel nitric oxide (NO)-dependent molecular switch mediating LTP in the Octopus vulgaris brain.", "url": "https://search.crossref.org/?q=A%20novel%20nitric%20oxide%20(NO)-dependent%20molecular%20switch%20mediating%20LTP%20in%20the%20Octopus%20vulgaris%20brain.", "doi": null } ] }, { "readingPosition": 10, "sourceChapter": 4, "title": "Problem Solving & Tool Use", "part": "III", "url": "https://octopuscognition.org/sections/problem-solving-tool-use/", "markdown": "https://octopuscognition.org/sections/problem-solving-tool-use/index.md", "description": "Octopuses are the textbook invertebrate problem-solvers, and the evidence spans controlled manipulation tasks, wild object use, and famous escapes. The most…", "shortAnswer": "Octopuses are the textbook invertebrate problem-solvers, and the evidence spans controlled manipulation tasks, wild object use, and famous escapes. The most cognitively resonant finding is defensive tool use in the veined (coconut) octopus, Amphioctopus marginatus (Finn, Tregenza & Norman, 2009, Current Biology).", "wordCount": 1261, "keyFindings": [ "The coconut octopus adopts a slower, clumsier 'stilt-walking' gait specifically to carry shells—paying an immediate locomotor and predation cost for a shelter it can only use later, the crux of the 'foresight' argument", "Giant Pacific octopuses learn to open human childproof medication bottles (a push-and-turn task) unaided, improving from 55 minutes to 5 minutes", "Gloomy octopuses throw silt and shells with siphon jets and sometimes appear to aim at other octopuses, who occasionally duck—one of very few non-human cases of possibly targeted throwing", "Octopuses can unscrew jar lids from the inside", "'Inky' the octopus escaped a New Zealand aquarium by crossing the floor and squeezing down a 50 m drainpipe to the ocean" ], "openQuestions": [ "Does coconut-shell carrying reflect genuine planning/mental representation of future need, or flexible associative learning? Finn explicitly could not rule out associative learning.", "Where should the definitional line for 'tool use' be drawn—immediate problem-solving, environmental modification, or deferred deployment—and is a set-aside, re-deployed shelter a tool?", "Is the debris-throwing in O. tetricus intentionally aggressive/social signaling, or an incidental byproduct of den-clearing that sometimes hits others?", "Do laboratory puzzle solutions (jars, L-container) involve any insight, or are they entirely trial-and-error/stimulus–response?", "How robust is the 1992 observational-learning result given later replication and interpretive concerns?" ], "trails": [ "intelligence-in-action" ], "sources": [ { "id": "source-042", "title": "Defensive tool use in a coconut-carrying octopus.", "url": "https://doi.org/10.1016/j.cub.2009.10.052", "doi": "10.1016/j.cub.2009.10.052" }, { "id": "source-065", "title": "In the line of fire: Debris throwing by wild octopuses.", "url": "https://doi.org/10.1371/journal.pone.0276482", "doi": "10.1371/journal.pone.0276482" }, { "id": "source-038", "title": "Pull or Push? Octopuses Solve a Puzzle Problem.", "url": "https://doi.org/10.1371/journal.pone.0152048", "doi": "10.1371/journal.pone.0152048" }, { "id": "source-037", "title": "'Home' choice and modification by juvenile Octopus vulgaris (Mollusca: Cephalopoda): specialized intelligence and tool use?.", "url": "https://doi.org/10.1111/j.1469-7998.1994.tb05270.x", "doi": "10.1111/j.1469-7998.1994.tb05270.x" }, { "id": "source-020", "title": "Observational Learning in Octopus vulgaris.", "url": "https://doi.org/10.1126/science.256.5056.545", "doi": "10.1126/science.256.5056.545" }, { "id": "source-072", "title": "Jar/childproof-bottle opening in giant Pacific octopus (Seattle Aquarium).", "url": "https://search.crossref.org/?q=Jar%2Fchildproof-bottle%20opening%20in%20giant%20Pacific%20octopus%20(Seattle%20Aquarium).", "doi": null } ] }, { "readingPosition": 11, "sourceChapter": 5, "title": "Observational Learning & Cognition Controversies in Octopuses", "part": "III", "url": "https://octopuscognition.org/sections/observational-learning-cognition-controversies-in-octopuses/", "markdown": "https://octopuscognition.org/sections/observational-learning-cognition-controversies-in-octopuses/index.md", "description": "The single most cited claim in cephalopod social cognition is also its most disputed. In Fiorito & Scotto (1992, Science 256:545–547), naïve Octopus…", "shortAnswer": "The single most cited claim in cephalopod social cognition is also its most disputed. In Fiorito & Scotto (1992, Science 256:545–547), naïve Octopus vulgaris \"observers\" watched trained demonstrators repeatedly attack one of two balls (red vs. white) in a simultaneous visual discrimination.", "wordCount": 1190, "keyFindings": [ "Observers reportedly learned FASTER than the demonstrators who had undergone full operant conditioning — a striking, much-quoted claim from the 1992 paper.", "The original author (Fiorito) and his sharpest critics (Biederman & Davey) later co-authored a 1998 follow-up that failed to find a preexposure benefit — a rare adversarial collaboration in comparative cognition.", "Octopuses are asocial, semelparous, and provide no parental care, so a genuine social-learning capacity would be evolutionarily paradoxical.", "Even neurally immature cuttlefish hatchlings (≤5 days) appear to socially modulate predatory behavior, with more observers than demonstrators reaching criterion." ], "openQuestions": [ "Can the 1992 observational-learning result be replicated with modern controls (pre-registration, blind scoring, adequate n) that rule out stimulus enhancement and arousal?", "Is any cephalopod 'social learning' genuine imitation, or is it always reducible to emulation, local/stimulus enhancement, or general associative priming?", "Why would robust social-learning machinery evolve in solitary, short-lived octopuses — is it a by-product of general-purpose learning rather than an adaptation?", "How much of the octopus-cognition literature would survive replication given small samples and publication bias toward 'clever' results?", "Do octopuses show any latent/contingent learning, or does the failure of preexposure paradigms (Fiorito et al. 1998) indicate a real limit?" ], "trails": [ "intelligence-in-action" ], "sources": [ { "id": "source-020", "title": "Observational Learning in Octopus vulgaris.", "url": "https://doi.org/10.1126/science.256.5056.545", "doi": "10.1126/science.256.5056.545" }, { "id": "source-021", "title": "Social Learning in Invertebrates.", "url": "https://doi.org/10.1126/science.259.5101.1627", "doi": "10.1126/science.259.5101.1627" }, { "id": "source-023", "title": "The role of stimulus preexposure in problem solving by Octopus vulgaris.", "url": "https://doi.org/10.1007/s100710050015", "doi": "10.1007/s100710050015" }, { "id": "source-046", "title": "Can cuttlefish learn by observing others?.", "url": "https://doi.org/10.1007/s10071-012-0573-z", "doi": "10.1007/s10071-012-0573-z" }, { "id": "source-004", "title": "How intelligent is a cephalopod? Lessons from comparative cognition.", "url": "https://doi.org/10.1111/brv.12651", "doi": "10.1111/brv.12651" }, { "id": "source-018", "title": "Neurally underdeveloped cuttlefish newborns exhibit social learning.", "url": "https://doi.org/10.1007/s10071-020-01411-1", "doi": "10.1007/s10071-020-01411-1" }, { "id": "source-067", "title": "Octopus intelligence: the importance of being agnostic (commentary on Mather).", "url": "https://search.crossref.org/?q=Octopus%20intelligence%3A%20the%20importance%20of%20being%20agnostic%20(commentary%20on%20Mather).", "doi": null } ] }, { "readingPosition": 12, "sourceChapter": 6, "title": "Play Behavior and Individual Personality in Octopuses", "part": "III", "url": "https://octopuscognition.org/sections/play-behavior-and-individual-personality-in-octopuses/", "markdown": "https://octopuscognition.org/sections/play-behavior-and-individual-personality-in-octopuses/index.md", "description": "Octopuses hold a peculiar place in comparative psychology: solitary, short-lived molluscs that nonetheless became the first invertebrates credited with both…", "shortAnswer": "Octopuses hold a peculiar place in comparative psychology: solitary, short-lived molluscs that nonetheless became the first invertebrates credited with both individual personality and play. Both claims originated in a single collaboration between Jennifer Mather (University of Lethbridge) and aquarist Roland Anderson (Seattle Aquarium).", "wordCount": 1422, "keyFindings": [ "Octopuses were the first invertebrates ever shown to have consistent individual personalities (Mather & Anderson 1993) and the first shown to play (1999) — both from the same aquarist-scientist duo.", "In the founding play study only 2 of 8 octopuses actually played, by jetting water to bounce a pill bottle against the tank current — play was individual, not species-typical.", "Play reliably appears only AFTER exploration is exhausted (days 3–6 in Kuba et al. 2006), supporting the idea that curiosity must be satisfied before an animal 'plays'.", "Play was unaffected by hunger, age, or sex — arguing it is not disguised foraging.", "The bold–shy axis is context-specific in cephalopods: an animal bold under threat is not necessarily bold when feeding, undermining the notion of a single generalizable personality type.", "Juvenile octopus temperament changes with age and carries a heritable (relatedness) signal, despite octopuses being essentially solitary with no parental care." ], "openQuestions": [ "Is octopus 'play' genuinely play, or prolonged exploration/arousal? The distinction rests on Burghardt's criteria and tiny samples (often 2–3 individuals).", "What is the neural basis of individual differences — do personality axes map onto identifiable circuits in the vertical lobe or elsewhere?", "How stable are personality traits across a single octopus's short (1–2 year) semelparous lifespan?", "Does play have any fitness function in a solitary, fast-growing animal, or is it a byproduct of large brains and manipulative arms (convergent with vertebrates)?", "Why do only a minority of individuals play, and is play propensity itself a stable personality trait linked to activity/boldness?", "Do the 1993 factors (activity, reactivity, avoidance) truly replicate across species and labs, or are the labels artifacts of specific test batteries?" ], "trails": [ "inner-life", "intelligence-in-action" ], "sources": [ { "id": "source-057", "title": "Personalities of octopuses (Octopus rubescens).", "url": "https://doi.org/10.1037/0735-7036.107.3.336", "doi": "10.1037/0735-7036.107.3.336" }, { "id": "source-058", "title": "Exploration, play, and habituation in octopuses (Octopus dofleini).", "url": "https://doi.org/10.1037/0735-7036.113.3.333", "doi": "10.1037/0735-7036.113.3.333" }, { "id": "source-047", "title": "When do octopuses play? Effects of repeated testing, object type, age, and food deprivation on object play in Octopus vulgaris.", "url": "https://doi.org/10.1037/0735-7036.120.3.184", "doi": "10.1037/0735-7036.120.3.184" }, { "id": "source-085", "title": "Early temperamental traits in an octopus (Octopus bimaculoides).", "url": "https://doi.org/10.1037//0735-7036.115.4.351-364", "doi": "10.1037//0735-7036.115.4.351-364" }, { "id": "source-012", "title": "The Genesis of Animal Play: Testing the Limits.", "url": "https://doi.org/10.1002/ajhb.20433", "doi": "10.1002/ajhb.20433" }, { "id": "source-084", "title": "Personality traits in dumpling squid (Euprymna tasmanica): context-specific traits and their correlation with biological characteristics.", "url": "https://doi.org/10.1037/0735-7036.119.1.99", "doi": "10.1037/0735-7036.119.1.99" }, { "id": "source-035", "title": "Evidence of play behavior in captive California two-spot octopuses (Octopus bimaculoides).", "url": "https://doi.org/10.1371/journal.pone.0326379", "doi": "10.1371/journal.pone.0326379" }, { "id": "source-048", "title": "Exploration and habituation in intact free-moving Octopus vulgaris.", "url": "https://doi.org/10.46867/ijcp.2006.19.04.02", "doi": "10.46867/ijcp.2006.19.04.02" } ] }, { "readingPosition": 13, "sourceChapter": 7, "title": "Social Cognition, Octopolis & Signaling", "part": "III", "url": "https://octopuscognition.org/sections/social-cognition-octopolis-signaling/", "markdown": "https://octopuscognition.org/sections/social-cognition-octopolis-signaling/index.md", "description": "The octopus's textbook reputation as an antisocial loner has been substantially revised by fieldwork at two remarkable sites in Jervis Bay, New South Wales.…", "shortAnswer": "The octopus's textbook reputation as an antisocial loner has been substantially revised by fieldwork at two remarkable sites in Jervis Bay, New South Wales. Octopolis, discovered in 2009 by diver Matthew Lawrence and philosopher-scientist Peter Godfrey-Smith, formed around a 30 cm human-made metal object on an otherwise flat, muddy seabed at 15 m; the…", "wordCount": 1273, "keyFindings": [ "A supposedly solitary invertebrate settles disputes with graded color signals: dark = aggressive, pale = submissive, following an almost game-theoretic escalation logic (dark-vs-dark fights; dark-vs-pale ends in retreat).", "Octopuses throw silt and shells using a siphon jet fired from under the arm web, and throws are more vigorous and more likely to hit others in social contexts - one of the only cases of projectile-throwing at conspecifics outside social mammals.", "Females did nearly all the throwing (90 of 101 throws), and dark-bodied (aggressive-state) animals threw hardest (p<0.0001).", "Octopus cyanea punches partner fish to enforce cooperation, and 3D tracking shows leadership is distributed - fish scout and steer while the octopus controls movement timing, not a simple octopus dictatorship.", "Octopolis was seeded by a single human-made metal object; Octlantis proved the phenomenon occurs naturally around rock outcrops too." ], "openQuestions": [ "Is debris-throwing genuinely intentional/targeted at specific individuals, or an incidental byproduct of den-cleaning? (Actively debated; Godfrey-Smith et al. 2023 'toss-up' revisits this.)", "Is aggregation an evolved sociality or merely forced tolerance driven by scarce denning substrate plus abundant food?", "What are the fitness consequences (mating success, predation, mortality) of living at high density in Octopolis/Octlantis?", "How cognitively flexible is Octopus cyanea's partner-control - does it represent true social cognition or simpler stimulus-response enforcement?", "Do these social behaviors occur across other octopus species, or are they idiosyncratic to O. tetricus and O. cyanea in specific habitats?" ], "trails": [ "intelligence-in-action" ], "sources": [ { "id": "source-078", "title": "Signal Use by Octopuses in Agonistic Interactions.", "url": "https://doi.org/10.1016/j.cub.2015.12.033", "doi": "10.1016/j.cub.2015.12.033" }, { "id": "source-077", "title": "A second site occupied by Octopus tetricus at high densities, with notes on their ecology and behavior (Octlantis).", "url": "https://doi.org/10.1080/10236244.2017.1369851", "doi": "10.1080/10236244.2017.1369851" }, { "id": "source-065", "title": "In the line of fire: Debris throwing by wild octopuses.", "url": "https://doi.org/10.1371/journal.pone.0276482", "doi": "10.1371/journal.pone.0276482" }, { "id": "source-074", "title": "Octopuses punch fishes during collaborative interspecific hunting events.", "url": "https://doi.org/10.1002/ecy.3266", "doi": "10.1002/ecy.3266" }, { "id": "source-073", "title": "Multidimensional social influence drives leadership and composition-dependent success in octopus-fish hunting groups.", "url": "https://doi.org/10.1038/s41559-024-02525-2", "doi": "10.1038/s41559-024-02525-2" }, { "id": "source-079", "title": "Octopus engineering, intentional and inadvertent.", "url": "https://doi.org/10.1080/19420889.2017.1395994", "doi": "10.1080/19420889.2017.1395994" } ] }, { "readingPosition": 14, "sourceChapter": 17, "title": "Numerical, Quantity, and Abstract-Concept Cognition in Cephalopods (with Cross-Modal and Mirror/Self Tests)", "part": "III", "url": "https://octopuscognition.org/sections/numerical-quantity-and-abstract-concept-cognition-in-cephalopods-with-cross-modal-and-mirror-self-tests/", "markdown": "https://octopuscognition.org/sections/numerical-quantity-and-abstract-concept-cognition-in-cephalopods-with-cross-modal-and-mirror-self-tests/index.md", "description": "Cephalopod \"higher-order\" cognition splits into three uneven strands: solid evidence for approximate number/quantity representation and cognitive control…", "shortAnswer": "Cephalopod \"higher-order\" cognition splits into three uneven strands: solid evidence for approximate number/quantity representation and cognitive control (mostly in cuttlefish), suggestive but thin evidence for cross-modal integration and abstract concepts, and largely negative results for mirror self-recognition.", "wordCount": 1210, "keyFindings": [ "Cuttlefish reverse their numerical preference based on hunger: hungry animals pick one large prey, satiated ones pick two small—number choice is value-driven, not fixed.", "Longer delay-of-gratification tolerance predicts faster learning in cuttlefish, mirroring the human 'marshmallow test' correlation in a mollusc with no shared ancestry for such control.", "Some cuttlefish physically turn away from tempting food, resembling self-distraction strategies documented in children and apes.", "Octopus object recognition is tactile-DOMINANT: they trust touch over vision when forming representations of novel objects, the reverse of the human default.", "The 'self-directed' mark-touching octopuses do in mirror tests happens just as often with no mirror and in sham-marked animals—it's proprioception, not self-recognition.", "Numerical discrimination follows Weber's law (ratio-dependent), meaning cuttlefish use an analog approximate-number system rather than exact counting or subitizing." ], "openQuestions": [ "Do any cephalopods possess genuine abstract relational concepts (same/different, identity) that transfer to novel stimuli, as pigeons and archerfish do? No convincing demonstration exists yet.", "Is octopus numerical competence comparable to cuttlefish, or is the near-total reliance on cuttlefish data an artifact of species testability?", "Does the semi-autonomous arm nervous system share fully unified cross-modal representations with the central brain, or only partially?", "Why do squid, cuttlefish, and octopus differ so sharply in mirror-reflection responsiveness, and does any paradigm could reveal non-visual self-representation in octopuses?", "Can Weber-law quantity discrimination in cephalopods be dissociated from continuous non-numerical cues (surface area, density, movement)?", "How do these convergent 'cognitive control' abilities map onto cephalopod neuroanatomy (vertical lobe) relative to the mammalian prefrontal cortex?" ], "trails": [ "intelligence-in-action" ], "sources": [ { "id": "source-102", "title": "Number sense and state-dependent valuation in cuttlefish.", "url": "https://doi.org/10.1098/rspb.2016.1379", "doi": "10.1098/rspb.2016.1379" }, { "id": "source-080", "title": "Cuttlefish exert self-control in a delay of gratification task.", "url": "https://doi.org/10.1098/rspb.2020.3161", "doi": "10.1098/rspb.2020.3161" }, { "id": "source-033", "title": "Do cuttlefish have fraction number sense?.", "url": "https://doi.org/10.1007/s10071-018-01232-3", "doi": "10.1007/s10071-018-01232-3" }, { "id": "source-045", "title": "Cross-Modal Object Recognition and Reliability Between Visual and Tactile Senses in Octopus (Callistoctopus aspilosomatis).", "url": "https://doi.org/10.2108/zs240069", "doi": "10.2108/zs240069" }, { "id": "source-055", "title": "A preliminary attempt to investigate mirror self-recognition in Octopus vulgaris.", "url": "https://doi.org/10.3389/fphys.2022.951808", "doi": "10.3389/fphys.2022.951808" }, { "id": "source-004", "title": "How intelligent is a cephalopod? Lessons from comparative cognition.", "url": "https://doi.org/10.1111/brv.12651", "doi": "10.1111/brv.12651" } ] }, { "readingPosition": 15, "sourceChapter": 9, "title": "Sleep, Two-Stage Sleep, and Possible Dreaming in Octopuses", "part": "IV", "url": "https://octopuscognition.org/sections/sleep-two-stage-sleep-and-possible-dreaming-in-octopuses/", "markdown": "https://octopuscognition.org/sections/sleep-two-stage-sleep-and-possible-dreaming-in-octopuses/index.md", "description": "Sleep in octopuses was first established behaviorally, then—remarkably—shown to have a two-stage architecture rivaling the vertebrate distinction between…", "shortAnswer": "Sleep in octopuses was first established behaviorally, then—remarkably—shown to have a two-stage architecture rivaling the vertebrate distinction between non-REM and REM sleep. The foundational work (Brown et al., 2006; Meisel et al., 2011) demonstrated that Octopus vulgaris meets the classical behavioral criteria for sleep: a reversible quiescent state…", "wordCount": 1279, "keyFindings": [ "Active-sleep LFP brain activity in the octopus is nearly indistinguishable from waking activity (Pearson R up to 0.95 in high-frequency bands), yet arousal thresholds are highest during this stage.", "Quiet sleep contains 12–18 Hz oscillatory events lasting 1 s that resemble mammalian sleep spindles—strikingly convergent given 550 million years of separate evolution and no homologous brain structures.", "During active sleep, octopuses rapidly cycle their skin through the exact camouflage patterns they use while awake, hinting at offline 'replay' or rehearsal of skin-pattern control.", "Sleep-deprived octopuses rebound specifically by increasing active-sleep bouts, proving the REM-like stage is homeostatically defended and essential, not incidental.", "Active-sleep interval timing is temperature-dependent: a 1°C rise shortens the cycle by roughly 5 minutes.", "A preprint reports bizarre 'nightmare-like' abnormal episodes in senescing octopuses, though this is anecdotal." ], "openQuestions": [ "Do octopuses subjectively experience anything dream-like during active sleep, or is the skin-pattern 'replay' purely offline motor maintenance with no phenomenology? This is likely unanswerable with current methods.", "Is the skin-pattern cycling during active sleep true memory replay (like hippocampal replay) or stochastic churn through the motor repertoire?", "What is the mechanistic function of the sleep-spindle-like 12–18 Hz waveforms in quiet sleep—memory consolidation, as in mammals?", "Given non-homologous brains, is two-stage sleep a case of deep convergent evolution driven by shared computational constraints, or independent solutions that merely look alike?", "Do young, healthy octopuses show the same 'abnormal'/parasomnia-like episodes, or are those artifacts of senescence and captivity?", "How generalizable are findings across octopus species (O. insularis, O. laqueus, O. vulgaris) and to other coleoid cephalopods?" ], "trails": [ "inner-life" ], "sources": [ { "id": "source-001", "title": "Wake-like skin patterning and neural activity during octopus sleep.", "url": "https://doi.org/10.1038/s41586-023-06203-4", "doi": "10.1038/s41586-023-06203-4" }, { "id": "source-091", "title": "Cyclic alternation of quiet and active sleep states in the octopus.", "url": "https://doi.org/10.1016/j.isci.2021.102223", "doi": "10.1016/j.isci.2021.102223" }, { "id": "source-054", "title": "A preliminary analysis of sleep-like states in the cuttlefish Sepia officinalis.", "url": "https://doi.org/10.1371/journal.pone.0038125", "doi": "10.1371/journal.pone.0038125" }, { "id": "source-094", "title": "Cyclic nature of the REM sleep-like state in the cuttlefish Sepia officinalis.", "url": "https://doi.org/10.1242/jeb.174862", "doi": "10.1242/jeb.174862" }, { "id": "source-016", "title": "Contribution of the visual system of the octopus to determination of sleep-like behavior.", "url": "https://search.crossref.org/?q=Contribution%20of%20the%20visual%20system%20of%20the%20octopus%20to%20determination%20of%20sleep-like%20behavior.", "doi": null }, { "id": "source-017", "title": "Brain and behavioural evidence for rest-activity cycles in Octopus vulgaris.", "url": "https://doi.org/10.1016/j.bbr.2006.05.009", "doi": "10.1016/j.bbr.2006.05.009" } ] }, { "readingPosition": 16, "sourceChapter": 11, "title": "Nociception, Pain, and Sentience in Octopuses", "part": "IV", "url": "https://octopuscognition.org/sections/nociception-pain-and-sentience-in-octopuses/", "markdown": "https://octopuscognition.org/sections/nociception-pain-and-sentience-in-octopuses/index.md", "description": "Octopuses have moved, within a decade, from textbook examples of \"reflex-only\" invertebrates to the strongest invertebrate case for genuine pain experience.…", "shortAnswer": "Octopuses have moved, within a decade, from textbook examples of \"reflex-only\" invertebrates to the strongest invertebrate case for genuine pain experience. The empirical foundation was laid by Robyn Crook and colleagues. In squid, Crook, Hanlon & Walters (2013, J.", "wordCount": 1354, "keyFindings": [ "Crook's 2021 study is claimed to be the first demonstration of probable ongoing/tonic (spontaneous) pain in ANY non-mammalian animal, not merely reflexive nociception.", "Analgesia (lidocaine) was rewarding only to octopuses that had experienced pain—controls showed no preference—separating the affective 'suffering' dimension from mere sensation.", "Nociceptive sensitization is adaptive, not just a byproduct of damage: sensitized injured squid escaped predators better, and anesthetizing the wound removed the survival advantage (Crook et al. 2014).", "Octopus nociceptors show mammalian-style long-term sensitization and spontaneous firing, despite 500 million years of divergent evolution—a case of convergent pain machinery.", "The LSE report's recommendation against octopus farming rippled into real bans in Washington State and California and a proposed U.S. federal OCTOPUS Act (2024).", "Nautilus sentience is essentially unknown (1/8 criteria met with confidence), showing 'cephalopod' sentience is far from uniform across the class." ], "openQuestions": [ "Which molecular receptors/ion channels transduce noxious stimuli in octopuses, and do they resemble vertebrate TRP-family or Nav nociceptor channels? (2025 C. elegans-based functional work is only beginning to answer this.)", "Do octopuses possess endogenous analgesic/opioid or descending pain-modulation systems, and where are they located in a decentralized nervous system?", "Can conditioned place avoidance/preference results be fully explained by non-conscious reinforcement, or do they genuinely index subjective negative affect?", "Where, if anywhere, is pain 'integrated' in an animal with two-thirds of its neurons in semi-autonomous arms—does the vertical/frontal lobe system serve as the integrative substrate the sentience criteria require?", "How generalizable are findings from a few species (O. bocki, D. pealeii) across the 300 octopus species and other coleoids?", "What welfare-relevant thresholds (e.g., humane slaughter methods) follow from sentience recognition, given no validated stunning protocol exists for cephalopods?" ], "trails": [ "inner-life" ], "sources": [ { "id": "source-069", "title": "Behavioral and neurophysiological evidence suggests affective pain experience in octopus.", "url": "https://doi.org/10.1016/j.isci.2021.102229", "doi": "10.1016/j.isci.2021.102229" }, { "id": "source-039", "title": "Review of the Evidence of Sentience in Cephalopod Molluscs and Decapod Crustaceans (LSE report for DEFRA).", "url": "https://eprints.lse.ac.uk/115994/", "doi": null }, { "id": "source-071", "title": "Squid have nociceptors that display widespread long-term sensitization and spontaneous activity after bodily injury.", "url": "https://doi.org/10.1523/jneurosci.0646-13.2013", "doi": "10.1523/jneurosci.0646-13.2013" }, { "id": "source-070", "title": "Nociceptive sensitization reduces predation risk.", "url": "https://doi.org/10.1016/j.cub.2014.03.043", "doi": "10.1016/j.cub.2014.03.043" }, { "id": "source-036", "title": "Arm injury produces long-term behavioral and neural hypersensitivity in octopus.", "url": "https://doi.org/10.1016/j.neulet.2013.11.002", "doi": "10.1016/j.neulet.2013.11.002" }, { "id": "source-003", "title": "Sentience in cephalopod molluscs: an updated assessment.", "url": "https://doi.org/10.1002/brv.70125", "doi": "10.1002/brv.70125" }, { "id": "source-009", "title": "Designing Brains for Pain: Human to Mollusc (and related work).", "url": "https://search.crossref.org/?q=Designing%20Brains%20for%20Pain%3A%20Human%20to%20Mollusc%20(and%20related%20work).", "doi": null } ] }, { "readingPosition": 17, "sourceChapter": 14, "title": "Research Methods, Welfare in the Lab & Future Directions", "part": "IV", "url": "https://octopuscognition.org/sections/research-methods-welfare-in-the-lab-future-directions/", "markdown": "https://octopuscognition.org/sections/research-methods-welfare-in-the-lab-future-directions/index.md", "description": "Modern octopus cognition research descends from J.Z. Young and B.B. Boycott's lesion-and-learning program at the Stazione Zoologica in Naples (from 1947),…", "shortAnswer": "Modern octopus cognition research descends from J.Z. Young and B.B. Boycott's lesion-and-learning program at the Stazione Zoologica in Naples (from 1947), which localized separate tactile and visual memory stores and established the vertical lobe as the mollusc's learning-and-memory center—removing it spared general behavior but abolished acquisition of…", "wordCount": 1529, "keyFindings": [ "Cephalopods are the ONLY invertebrates regulated for research welfare in the EU (Directive 2010/63/EU, since 2013)—an entire animal class regulated for the first time.", "Standard behavioral tech fails on octopuses: Skinner-box lever-pressing was never reliably learned and trap-tube tasks are meaningless because flexible arms just reach around obstacles.", "Octopuses are semelparous and die within 1–2 years after a single brood, so lab animals are mostly wild-caught and cannot be aged into longitudinal studies.", "The first brain waves from freely moving octopuses were recorded with data loggers originally built to track bird brains during flight—waterproofed and implanted in the mantle cavity.", "Washington State passed the world's first legislative ban on octopus farming (2024) before any commercial farm even opened.", "Some historic 'reversal learning' results may partly reflect electric-shock reinforcement and experimenter cueing rather than pure cognition.", "The genetic future of cephalopod neuroscience may hinge not on octopuses but on a tiny transparent gene-edited bobtail squid (Euprymna berryi)." ], "openQuestions": [ "Can standardized, welfare-compliant cognitive test batteries be validated across labs, or will apparatus-dependence keep octopus cognition results hard to replicate?", "Is the hippocampus-like LFP activity seen in freely moving octopuses functionally analogous to vertebrate memory consolidation, or a superficial resemblance?", "Will CRISPR tractability transfer efficiently from bobtail squid to true octopuses, whose long single-brood life cycle resists multigenerational genetics?", "How do you humanely slaughter and house a solitary, sentient invertebrate at commercial scale—or is welfare-compatible octopus farming simply impossible?", "What is the minimal severity threshold for implanting electrodes/loggers in an animal now legally recognized as capable of suffering?", "Can a whole-brain octopus connectome be reconstructed given 500 million neurons, two-thirds of them distributed in the arms?", "Do octopuses possess centralized 'flexible intelligence' or is much apparent cognition emergent from semi-autonomous arm nervous systems, complicating brain-centric paradigms?" ], "trails": [ "inner-life" ], "sources": [ { "id": "source-013", "title": "The octopus genome and the evolution of cephalopod neural and morphological novelties.", "url": "https://doi.org/10.1038/nature14668", "doi": "10.1038/nature14668" }, { "id": "source-025", "title": "Recording electrical activity from the brain of behaving octopus.", "url": "https://doi.org/10.1016/j.cub.2023.02.006", "doi": "10.1016/j.cub.2023.02.006" }, { "id": "source-015", "title": "Highly efficient knockout of a squid pigmentation gene (first CRISPR knockout in a cephalopod).", "url": "https://search.crossref.org/?q=Highly%20efficient%20knockout%20of%20a%20squid%20pigmentation%20gene%20(first%20CRISPR%20knockout%20in%20a%20cephalopod).", "doi": null }, { "id": "source-060", "title": "Creation of an albino squid line by CRISPR-Cas9 and its application for in vivo functional imaging of neural activity.", "url": "https://doi.org/10.2139/ssrn.4369821", "doi": "10.2139/ssrn.4369821" }, { "id": "source-039", "title": "Review of the Evidence of Sentience in Cephalopod Molluscs and Decapod Crustaceans (LSE report for DEFRA).", "url": "https://eprints.lse.ac.uk/115994/", "doi": null }, { "id": "source-019", "title": "Guidelines for the Care and Welfare of Cephalopods in Research.", "url": "https://search.crossref.org/?q=Guidelines%20for%20the%20Care%20and%20Welfare%20of%20Cephalopods%20in%20Research.", "doi": null }, { "id": "source-086", "title": "Cephalopod research and EU Directive 2010/63/EU: Requirements, impacts and ethical review.", "url": "https://doi.org/10.1016/j.jembe.2013.02.009", "doi": "10.1016/j.jembe.2013.02.009" }, { "id": "source-103", "title": "Vertical-lobe ablation and touch/visual learning centres in Octopus.", "url": "https://search.crossref.org/?q=Vertical-lobe%20ablation%20and%20touch%2Fvisual%20learning%20centres%20in%20Octopus.", "doi": null }, { "id": "source-011", "title": "Reconsideration of Serial Visual Reversal Learning in Octopus from a Methodological Perspective.", "url": "https://doi.org/10.3389/fphys.2017.00054", "doi": "10.3389/fphys.2017.00054" }, { "id": "source-038", "title": "Pull or Push? Octopuses Solve a Puzzle Problem.", "url": "https://doi.org/10.1371/journal.pone.0152048", "doi": "10.1371/journal.pone.0152048" } ] } ], "counts": { "chapters": 17, "trails": 5, "surprises": 99, "openQuestions": 97, "debates": 7, "sources": 104 } }