Heh, I’ve gone the opposite way and now do 3h sleep per 12h-days. The aim is to wake up during REM/light-sleep at the end of the 2nd sleep cycle, but I don’t have a clever way of measuring this[1] except regular sleep-&-wake-times within the range of what the brain can naturally adapt its cycles to.
I think the objective should be to maximize the integral of cognitive readiness over time,[2] so here are some considerations (sorry for lack of sources; feel free to google/gpt; also also sorry for sorta redundant here, but I didn’t wish to spend time paring it down):
Restorative effects of sleep have diminishing marginal returns
I think a large reason we sleep is that metabolic waste-clearance is more efficiently batch-processed, because optimal conditions for waste-clearance are way different from optimal conditions for cognition (and substantial switching-costs between, as indicated by how difficult it can be to actually start sleeping). And this differentially takes place during deep sleep.
Proportion of REM-sleep in a cycle increases per cycle, with a commensurate decrease in deep sleep (SWS).
Two unsourced illustrations I found in my notes:
Note how N3 (deep sleep) drops off fairly drastically after 3 hours (~2 full sleep cycles).
REM & SWS do different things, and I like the things SWS do more
Eg acetylcholine levels (ACh) are high during REM & awake, and low during SWS. ACh functions as a switch between consolidation & encoding of new memories.[3] Ergo REM is for exploring/generalizing novel patterns, and SWS is for consolidating/filtering them.
REM seems to differentially improve procedural memories, whereas SWS more for declarative memories.
(And who cares about procedural memories anyway. :p)
(My most-recent-pet-hunch is that ACh is required for integrating new episodic memories into hippocampal theta waves (via the theta-generating Medial Septum in the Cholinergic Basal Forebrain playing ‘conductor’ for the hippocampus), which is why you can’t remember anything from deep sleep, and why drugs that inhibit ACh also prevent encoding new memories.)
So in summary, two (comparatively minor) reasons I like polyphasic short sleep is:
SWS differentially improves declarative over procedural memories.
Early cycles have proportionally more SWS.
Ergo more frequent shorter sleep sessions will maximize the proportion of sleep that goes to consolidation of declarative memories.
Note: I think the exploratory value of REM-sleep is fairly limited, just based on the personal observation that I mostly tend to dream about pleasant social situations, and much less about topics related to conceptual progress. I can explore much more efficiently while I’m awake.
Also, because I figure my REM-dreams are so socially-focused, I think more of it risks marginally aligning my daily motivations with myopically impressing others, at the cost of motivations aimed at more abstract/illegible/longterm goals.
(Although I would change my mind if only I could manage to dream of Maria more, since trying to impress her is much more aligned with our-best-guess about what saves the world compared to anything else.)
And because diminishing marginal returns to sleep-duration, and assuming cognition is best in the morning (anecdotally true), I maximize high-quality cognition by just… having more mornings preceded by what-best-I-can-tell-is-near-optimal-sleep (ceiling effect).
Lastly, just anecdotally, having two waking-sessions per 24h honestly just feels like I have ~twice the number of days in a week in terms of productivity. This is much more convincing to me than the above.
Starting mornings correctly seems to be incredibly important, and some of the effect of those good morning-starts dissipate the longer I spend awake. Mornings work especially well as hooks/cues for starting effective routines, sorta like a blank slate[4] you can fill in however I want if I can get the cues in before anything else has time to hijack the day’s cognition/motivations.
My mood is harder to control/predict in evenings due to compounding butterfly effects over the course of a day, and fewer natural contexts I can hook into with the right course-corrections before the day ends.
PedanticallyTechnically, we want to maximize brain-usefwlness over time, which in this case would be the integral of [[the distribution cognitive readiness over time] pointwise multiplied by [the distribution of brain-usefwlness over cognitive readiness]].
This matters if, for example, you get disproportionately more usefwlness from the peaks of cognitive readiness, in which case you might want to sacrifice more median wake-time in order to get marginally more peak-time.
I assume this is what your suggested strategy tries to do. However, I doubt it actually works, due to diminishing returns to marginal sleep time (and, I suspect,
“Blank slate” I think caused by eg flushing neurotransmitters out of synaptic clefts (and maybe glucose and other mobile things), basically rebooting attentional selection-history, and thereby reducing recent momentum for whatever’s influenced you short-term.
Heh, I’ve gone the opposite way and now do 3h sleep per 12h-days. The aim is to wake up during REM/light-sleep at the end of the 2nd sleep cycle, but I don’t have a clever way of measuring this[1] except regular sleep-&-wake-times within the range of what the brain can naturally adapt its cycles to.
I think the objective should be to maximize the integral of cognitive readiness over time,[2] so here are some considerations (sorry for lack of sources; feel free to google/gpt; also also sorry for sorta redundant here, but I didn’t wish to spend time paring it down):
Restorative effects of sleep have diminishing marginal returns
I think a large reason we sleep is that metabolic waste-clearance is more efficiently batch-processed, because optimal conditions for waste-clearance are way different from optimal conditions for cognition (and substantial switching-costs between, as indicated by how difficult it can be to actually start sleeping). And this differentially takes place during deep sleep.
Eg interstitial space expands by ~<60% and the brain is flooded to flush out metabolic waste/debris via the glymphatic system.
Proportion of REM-sleep in a cycle increases per cycle, with a commensurate decrease in deep sleep (SWS).
Two unsourced illustrations I found in my notes:
Note how N3 (deep sleep) drops off fairly drastically after 3 hours (~2 full sleep cycles).
REM & SWS do different things, and I like the things SWS do more
Eg acetylcholine levels (ACh) are high during REM & awake, and low during SWS. ACh functions as a switch between consolidation & encoding of new memories.[3] Ergo REM is for exploring/generalizing novel patterns, and SWS is for consolidating/filtering them.
See also acetylcholine = learning-rate.
REM seems to differentially improve procedural memories, whereas SWS more for declarative memories.
(And who cares about procedural memories anyway. :p)
(My most-recent-pet-hunch is that ACh is required for integrating new episodic memories into hippocampal theta waves (via the theta-generating Medial Septum in the Cholinergic Basal Forebrain playing ‘conductor’ for the hippocampus), which is why you can’t remember anything from deep sleep, and why drugs that inhibit ACh also prevent encoding new memories.)
So in summary, two (comparatively minor) reasons I like polyphasic short sleep is:
SWS differentially improves declarative over procedural memories.
Early cycles have proportionally more SWS.
Ergo more frequent shorter sleep sessions will maximize the proportion of sleep that goes to consolidation of declarative memories.
Note: I think the exploratory value of REM-sleep is fairly limited, just based on the personal observation that I mostly tend to dream about pleasant social situations, and much less about topics related to conceptual progress. I can explore much more efficiently while I’m awake.
Also, because I figure my REM-dreams are so socially-focused, I think more of it risks marginally aligning my daily motivations with myopically impressing others, at the cost of motivations aimed at more abstract/illegible/longterm goals.
(Although I would change my mind if only I could manage to dream of Maria more, since trying to impress her is much more aligned with our-best-guess about what saves the world compared to anything else.)
And because diminishing marginal returns to sleep-duration, and assuming cognition is best in the morning (anecdotally true), I maximize high-quality cognition by just… having more mornings preceded by what-best-I-can-tell-is-near-optimal-sleep (ceiling effect).
Lastly, just anecdotally, having two waking-sessions per 24h honestly just feels like I have ~twice the number of days in a week in terms of productivity. This is much more convincing to me than the above.
Starting mornings correctly seems to be incredibly important, and some of the effect of those good morning-starts dissipate the longer I spend awake. Mornings work especially well as hooks/cues for starting effective routines, sorta like a blank slate[4] you can fill in however I want if I can get the cues in before anything else has time to hijack the day’s cognition/motivations.
See my (outdated-but-still-maybe-inspirational) my morning routine.
My mood is harder to control/predict in evenings due to compounding butterfly effects over the course of a day, and fewer natural contexts I can hook into with the right course-corrections before the day ends.
Although waking up with morning-wood is some evidence of REM, but I don’t know how reliable that is. ^^
PedanticallyTechnically, we want to maximize brain-usefwlness over time, which in this case would be the integral of [[the distribution cognitive readiness over time] pointwise multiplied by [the distribution of brain-usefwlness over cognitive readiness]].This matters if, for example, you get disproportionately more usefwlness from the peaks of cognitive readiness, in which case you might want to sacrifice more median wake-time in order to get marginally more peak-time.
I assume this is what your suggested strategy tries to do. However, I doubt it actually works, due to diminishing returns to marginal sleep time (and, I suspect,
> “Our findings support the notion that ACh acts as a switch between modes of acquisition and consolidation.” (2006)
> “Acetylcholine Mediates Dynamic Switching Between Information Coding Schemes in Neuronal Networks” (2019)
“Blank slate” I think caused by eg flushing neurotransmitters out of synaptic clefts (and maybe glucose and other mobile things), basically rebooting attentional selection-history, and thereby reducing recent momentum for whatever’s influenced you short-term.