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"If this were to be the case, this remarkable convergence of sleep behaviors in vertebrates and cephalopods points to the evolution of complex sleep in cognitiv

"If this were to be the case, this remarkable convergence of sleep behaviors in vertebrates and cephalopods points to the evolution of complex sleep in cognitively complex organisms with elaborate neural architectures." The last common ancestor of vertebrates and cephalopods is a flatworm 750 million years ago. So this is proposing that nightmares, and dreams, and even sleep(?) are examples of convergent evolution. Which gets weirder the more I think about it.

steve_adams_86 3y ago
There is a fairly viable hypothesis that dreaming could be regions of the brain attempting to kind of “protect their turf” by turning on and being active — thus necessary and relevant, and deserving real estate in the brain — as senses actually attempt to utilize brain regions utilized for other purposes throughout sleep. That’s why you can improve your ability to use various senses throughout life, such as if you go blind. This could have emerged a very, very, very long time ago in very simple organisms and thus could be present in most animals with a reasonably simple explanation. That humans have stories, language, and nightmares within dreams (and evidently dogs as well, regarding nightmares) could be a more sophisticated version of this protocol that might be a mammalian thing, but fundamentally uses the same protocol. It’s like various regions of your brain turning on to say hey, I’m still here, don’t overwrite me with that other stuff. It’s a hypothesis, but it’s a clean one I think. I like it. It works well to unify a lot of organisms and doesn’t seem so strange if it’s convergent — what’s really happening is more like a simulation to stimulate the brain. I realize as I write this that the simulation part is maybe the most fascinating aspect. Why isn’t it random noise? Well, perhaps because part of the way our brain works practically requires running it through the simulator. But why would that be the same for an octopus, assuming it is? That being convergent would be more surprising. However, maybe the underlying feature of brains running simulations is actually common to far more animals than we realize. A fly can anticipate something coming towards it and missing, and it won’t move. If the object will hit it, and assuming it’s not moving too quickly, the fly will move. Is the fly performing a simulation of the object to predict its path? Is that the same ancient simulation software? I’m just rambling. It’s an extremely interesting topic and I had two coffees instead of one this morning.
- gcanyon 3y ago
  Interesting ideas, I'm glad you had the extra coffee :-) I wonder though if "A fly can anticipate" is accurate? As you question, does the fly run a simulation -- or more generally, does it have a mental model of the world. Given the size of fly brains, my guess would be no -- that it's more of a "when I see this, I do that" sort of a thing, honed by millions of generations of ancestors into an unthinking, but effective, state machine. One thing I double-checked: our last common ancestor with insects is something like 500 million years ago -- much more recent than with octopuses. So even if there is some similarity with insects, that's no guarantee that it exists in octopuses as well. As an aside, it's weird to think that I have more in common with a fly than an octopus (genetically at least).

steve_adams_86 3y ago

There is a fairly viable hypothesis that dreaming could be regions of the brain attempting to kind of “protect their turf” by turning on and being active — thus necessary and relevant, and deserving real estate in the brain — as senses actually attempt to utilize brain regions utilized for other purposes throughout sleep. That’s why you can improve your ability to use various senses throughout life, such as if you go blind. This could have emerged a very, very, very long time ago in very simple organisms and thus could be present in most animals with a reasonably simple explanation. That humans have stories, language, and nightmares within dreams (and evidently dogs as well, regarding nightmares) could be a more sophisticated version of this protocol that might be a mammalian thing, but fundamentally uses the same protocol. It’s like various regions of your brain turning on to say hey, I’m still here, don’t overwrite me with that other stuff. It’s a hypothesis, but it’s a clean one I think. I like it. It works well to unify a lot of organisms and doesn’t seem so strange if it’s convergent — what’s really happening is more like a simulation to stimulate the brain. I realize as I write this that the simulation part is maybe the most fascinating aspect. Why isn’t it random noise? Well, perhaps because part of the way our brain works practically requires running it through the simulator. But why would that be the same for an octopus, assuming it is? That being convergent would be more surprising. However, maybe the underlying feature of brains running simulations is actually common to far more animals than we realize. A fly can anticipate something coming towards it and missing, and it won’t move. If the object will hit it, and assuming it’s not moving too quickly, the fly will move. Is the fly performing a simulation of the object to predict its path? Is that the same ancient simulation software? I’m just rambling. It’s an extremely interesting topic and I had two coffees instead of one this morning.

gcanyon 3y ago
Interesting ideas, I'm glad you had the extra coffee :-) I wonder though if "A fly can anticipate" is accurate? As you question, does the fly run a simulation -- or more generally, does it have a mental model of the world. Given the size of fly brains, my guess would be no -- that it's more of a "when I see this, I do that" sort of a thing, honed by millions of generations of ancestors into an unthinking, but effective, state machine. One thing I double-checked: our last common ancestor with insects is something like 500 million years ago -- much more recent than with octopuses. So even if there is some similarity with insects, that's no guarantee that it exists in octopuses as well. As an aside, it's weird to think that I have more in common with a fly than an octopus (genetically at least).