Sleep restores the brain to a state of criticality | Hacker News Reader

Sleep restores the brain to a state of criticality

nature.com

Since it's paywalled, here is the summary from the (recommended) BrainPost newsletter: https://www.brainpost.co/weekly-brainpost/2024/1/23/the-purp...

This bit was particularly interesting: "First, the authors found that more time in a waking state correlated with higher deviation from criticality (i.e., higher DCC scores) and more time in sleep correlated with lower DCC scores, consistent with their theory. Interestingly, the effect was greater when the rats spent more time moving during wake and the effect was absent when the rats were awake but in the dark. This suggested that not all wake experiences are the same and that more stimulation during a waking state can result in a greater deviation from criticality."

I have to admit I'm a little confused by this. I understand network criticality in terms of autocorrelation and crosscorrelation, but it seems like they define deviation from criticality in terms of duration of neural ensemble rest periods (they link to another paper for this DCC definition). So isn't this in a sense saying (very very roughly) something like "mice sleep more when their neurons are resting more than expected based on a power law distribution"? If so seems kind of tautological.

It's an interesting idea and kind of at the boundary of my understanding so I'm probably missing something.

What does this mean in the context of depression? Sleep deprivation is a method to treat depression for a short time until medication kicks in. In addition in the former melancholic depression there is a recognized pattern of mood improvement over the course of the day.

Well, if the lack of sleep decreases your cognitive performance, then maybe it treats depression because being sleep-deprived you start to forget how much your life sucks? Or in general, you have less mental energy, so you do less thinking, including negative thinking?

thx. you seem to have pointed out my vicious cycle.

it seems... i will wake up before i become conscious aware of how my life sucks... like waking up before having a nightmare. i will then be too lazy to be productive, waste my dopamine into thoughts about others... and then i will not have any good feeling of relieve and success (due to reaching my goals) when going to bed. (i suffer badly from bed-time-procrastination and insomnia.) the exit strategy would then imply that i would replace all those daily routines and useless habits that i would end up keeping to have further down that spiral. i should instead do the things that i procrastinate due to the excuse they do not seem urgent enough... replacing the useless with the not-urgent. that way i influence what my brain digests during my sleep.

the sleep-deprivation relaxes me to not judge my useless habits, but now that i know that, i can see myself from a different perspective, judge/plan differently what i will do next, take control...

i'm gonna try that now. :)

Perhaps depression (and by extension other mental health disorders) are a vector away from criticality in a different direction than the one that is refreshed by sleeping. Sum of vectors may partially cancel when depressed and sleep deprived. Needs more study.

"Criticality is a concept borrowed from physics that describes when a system of individual parts will be most effective at responding to an input."

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