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I've thought of dreams as unique in suspending self-doubt. For some reason, while in a dream, we are incapable of doubting what is going on. Everything feels in

I've thought of dreams as unique in suspending self-doubt. For some reason, while in a dream, we are incapable of doubting what is going on. Everything feels incredibly vivid and real. Then we wake up, and we go back to doubting: "Ah, must've been a dream!" Edit: Perhaps immersive psychedelics (LSD, ketamine) are similar actually. Speculatively, one could define "real" as our ability to doubt, "fantasy" as the suspension of doubt.

adamjb 6y ago
Dreams made a whole lot more sense to me when I learnt about idea of the brain as a predictive processing machine. It asserts that the brain works as a sort of recursive two-sided process, with theory creation on one side and evidence collecting on the other. Recursive in that the visual processing system might get a "is that a door?" theory from a higher level system, which it'll then answer by collecting and trying to match evidence from multiple lower level systems ("is that an edge?" "is that a shadow?" etc.) until it eventually reaches the level of processing stimuli directly, with each system on the way acting as both questioner and answerer. In this framework dreaming is when the evidence collecting side becomes a lot less rigorous than it usually is, so it says "sure, why not" without reference to a stimulus (i.e. a way to be falsified). In other words it's the brain's predictions continuously coming true.
- sundarurfriend 6y ago
  > brain as a predictive processing machine. It asserts that the brain works as a sort of recursive two-sided process, with theory creation on one side and evidence collecting on the other. SlateStarCodex has a nice article[1] about this. > The key insight: the brain is a multi-layer prediction machine. All neural processing consists of two streams: a bottom-up stream of sense data, and a top-down stream of predictions. These streams interface at each level of processing, comparing themselves to each other and adjusting themselves as necessary. > ... > You’re not seeing the world as it is, exactly. You’re seeing your predictions about the world, cashed out as expected sensations, then shaped/constrained by the actual sense data. [1] https://slatestarcodex.com/2017/09/05/book-review-surfing-uncertainty/ https://slatestarcodex.com/2017/09/05/book-review-surfing-un...
rtx 6y ago
One theory I had read a longtime ago was that nightmares were a way for the subconscious mind to wake-up the conscious mind.

adamjb 6y ago

Dreams made a whole lot more sense to me when I learnt about idea of the brain as a predictive processing machine. It asserts that the brain works as a sort of recursive two-sided process, with theory creation on one side and evidence collecting on the other. Recursive in that the visual processing system might get a "is that a door?" theory from a higher level system, which it'll then answer by collecting and trying to match evidence from multiple lower level systems ("is that an edge?" "is that a shadow?" etc.) until it eventually reaches the level of processing stimuli directly, with each system on the way acting as both questioner and answerer. In this framework dreaming is when the evidence collecting side becomes a lot less rigorous than it usually is, so it says "sure, why not" without reference to a stimulus (i.e. a way to be falsified). In other words it's the brain's predictions continuously coming true.

sundarurfriend 6y ago
> brain as a predictive processing machine. It asserts that the brain works as a sort of recursive two-sided process, with theory creation on one side and evidence collecting on the other. SlateStarCodex has a nice article[1] about this. > The key insight: the brain is a multi-layer prediction machine. All neural processing consists of two streams: a bottom-up stream of sense data, and a top-down stream of predictions. These streams interface at each level of processing, comparing themselves to each other and adjusting themselves as necessary. > ... > You’re not seeing the world as it is, exactly. You’re seeing your predictions about the world, cashed out as expected sensations, then shaped/constrained by the actual sense data. [1] https://slatestarcodex.com/2017/09/05/book-review-surfing-uncertainty/ https://slatestarcodex.com/2017/09/05/book-review-surfing-un...

rtx 6y ago

One theory I had read a longtime ago was that nightmares were a way for the subconscious mind to wake-up the conscious mind.