Summary

Octopuses are an independent experiment in complex minds. Humans and cephalopods diverged from a flattened, worm-like ancestor, then built intelligence along radically different paths: our centralized nervous system versus the octopus’s distributed, “ladder-like” brain. That makes cephalopods a powerful test of embodied cognition, subjective experience, and what consciousness can be.

Consciousness likely grows from the link between sensing and action, not sensation alone. Working memory, broadcast / integration, novelty-seeking, and flexible control turn perception into experience. Octopus arms complicate the picture: their local brains act independently yet remain consciously steerable – less like a single command center than a brain and arms “playing jazz.”

Chappy’s Review

An interesting investigation into how cephalopods think different than humans but not as relevant to cognitive science as I would’ve hoped. A good relaxing read though!

Key Takeaways

Notes

1: Meetings Across the Tree of Life

• Cephalopods have complex nervous systems
• Common ancestor to humans: flattened worm-like creature
• How did subjective consciousness evolve?
• “The sea is the original home of the mind”
• Philosophy, animals, and evolution

2: A History of Animals

• Multicellular likely arose due to improper cell division
• Two roles of nervous system: sensing and action
• More and more internal → brain
• Two views:
  • Sensory-motor view
  • Creating actions themselves
• Nervous systems likely originated 500-700 MYA with jellies, sponges
• Box jellyfish are the most capable non-bilatarian animals
• Scavenging → predation accelerated evolution

3: Mischief and Craft

• Octopuses uniquely have no hard parts except beak - very morphable
• Can tell they’re contained / experimented, recognize individual humans
• Not group social like other intelligent species
• Distributed, “ladder-like” brain / nervous system unlike other species with spinal chords
• Embodied cognition: body itself encodes intelligence and how we must deal with the environment
• ↑ unlike humans, octopuses have much less of this (eg. all soft so less bounded)

4: From White Noise to Consciousness

• Goal to explain evolution of subjective perception / consciousness
• How same sensory input leads to differing belief / actions
• Doesn’t accept that all living things have subjective experience (unless lots of evidence for it)
• Study: consciousness depends on the link between sensing and action (can’t just be sensing)
• Unity of senses is surprisingly not needed (eg. split brain)
• People can navigate around objects without consciously seeing
• We can only learn associations non-consciously if <1s between - otherwise needs conscious memory
• The latecomer view: ↑ thus consciousness only evolved recently
• The transformation view: opposing view that ↑ instead transformed subjective experience not brought into being by “”
• Studies proving pain is widely perceived among animals
• Seeking novelty is key to consciousness
• Octopus arm brains akin to automatic breathing but consciously controllable
• Or might be like brain and arms “playing jazz” - synthesis of two

5: Making Colors

• Cuttlefish can change colors spectacularly but can’t see color
• Brand new study shows Octopuses can see with their skin (in their arms)
• Reasons for color change evolution:
  1. Camouflage
  2. Signaling
• ↑ but there are clearly other social use cases too
• Might be used for communication

6: Our Minds and Others

• Is internal commentary necessary?
• Emerging consensus: not essential for the formation of complex thoughts
• Language is input and output
• Efference copy: brain sends copy of action to others parts of brain to adapt sensory input
  • Eg. walking around changes vision
• ↑ listening to yourself speak and correcting if it came out wrong → internal monologue
• 3 components of working memory:
  1. Phonological loop (audio)
  2. Visiospatial sketchpad (pictures + shapes)
  3. Executive control device (controls ↑↑)
• 2 things needed for consciousness:
  • Working memory / “workspace”
  • Broadcast / integration
• Unlike human thinking and writing, not much room for efference with cuttlefish changing colors

7: Experience Compressed

• Obvious evolutionary reasons for aging*
• Positive feedback loop of senescence

8: Octopolis

• Color indicative of aggression / status
• Octopolis is unique because it requires more social navigation
• Types of memory:
  • Episodic: what happened at X
  • Procedural: how to X
  • Semantic: what is X
• Octopolis faces immense climate change risk