Portions of the brain fall asleep and wake back up all the time (opens in new tab)

Taking some time to reflect on and consider my own thinking behavior has been interesting. Just like exploring any other system, subjecting myself to sleep stress (in order to meet aggressive deadlines) has allowed me to see what happens when certain things fail, revealing functional boundaries.

I see it as kind of analogous to when you starve a circuit/device of power - it behaves in unexpected ways, revealing implementation details.

Some examples that I remember: after a particularly long all nighter (I was a freshman in college and wanted to try it while I could still do it by choice and not necessity) I was editing an article I was writing for the school magazine. I was starting to fade and realized that I couldn't read and comprehend well-formed, meaningful sentences that I had just written.

I've noticed that when sleep deprived I notice different things and have a more diverse set of emergent thoughts/recall events. For example, today I noticed the plug for an electric oven at a restaurant I have not only been to at least 100 times, but have worked at for months. I randomly remembered the lyrics to China's five-year-plan song walking home from class. I will suddenly remember and think fragments in Spanish, despite not touching it for years.

Truly, it appears the nature of effective cognition is restricting all of the many responses to stimuli to those that are useful and relevant, and I think the parts of the brain that do that may have 'fallen asleep' in all those instances.

You know how every generation conceives of the brain as a machine that's analogous to the latest technology of that generation? Like in the 19th century, the brain was a steam engine, and then in the 20th it was a computer? Well, apparently now the brain is a smartphone.

I think we are getting closer to furthering the concept that dreaming isn't just a side-effect of thinking (or simply a defrag/clean-up routine upon the previous day's thoughts or the mind's expectations for tomorrow). It is itself the key to the thinking process, and sits above and commands the other "agents". It helps us deal with uncertainty and lack of rationality inherent in the universe and our incomplete understanding of it.

This reminds me of the Mental Modules popping in and out of existence from the Coursera course "Buddhism and Modern Psychology", in week 4: https://www.coursera.org/learn/science-of-meditation#syllabu....

I was recently reading my daughter a story after being woken up too early and 'half asleep'. I kept noticing that I had invented a line of text or two, and knew that I had done this because part of my brain wasn't awake enough to focus on or perhaps read the words on the page. So one part of my brain was watching another invent plot or dialogue, while aware that another was 'asleep'. Other times I became aware that the story-supplementing part was not functioning and was able to jolt myself back to a state where I could read and recite the current line.

Here's some amazing relevant research with so many consequences that I keep coming back to:

Partial sleep in the context of augmentation of brain function

Abstract:

Inability to solve complex problems or errors in decision making is often attributed to poor brain processing, and raises the issue of brain augmentation. Investigation of neuronal activity in the cerebral cortex in the sleep-wake cycle offers insights into the mechanisms underlying the reduction in mental abilities for complex problem solving. Some cortical areas may transit into a sleep state while an organism is still awake. Such local sleep would reduce behavioral ability in the tasks for which the sleeping areas are crucial. The studies of this phenomenon have indicated that local sleep develops in high order cortical areas. This is why complex problem solving is mostly affected by local sleep, and prevention of local sleep might be a potential way of augmentation of brain function. For this approach to brain augmentation not to entail negative consequences for the organism, it is necessary to understand the functional role of sleep. Our studies have given an unexpected answer to this question. It was shown that cortical areas that process signals from extero- and proprioreceptors during wakefulness, switch to the processing of interoceptive information during sleep. It became clear that during sleep all “computational power” of the brain is directed to the restoration of the vital functions of internal organs. These results explain the logic behind the initiation of total and local sleep. Indeed, a mismatch between the current parameters of any visceral system and the genetically determined normal range would provide the feeling of tiredness, or sleep pressure. If an environmental situation allows falling asleep, the organism would transit to a normal total sleep in all cortical areas. However, if it is impossible to go to sleep immediately, partial sleep may develop in some cortical areas in the still behaviorally awake organism. This local sleep may reduce both the “intellectual power” and the restorative function of sleep for visceral organs.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4013465/

Fascinating stuff, imo. I've definitely felt the difference between partial sleep restedness and total sleep restedness, and the idea of sleep pressure seems to line up with my experience and with my idea of explorable, falsifiable models of phenomena. The idea that we dream while processing internal organ information is beautiful to me on multiple levels- maybe memory consolidation has a whole lot to do with pre-existing organ health! Maybe instead of the idea that we dream with only our heads, we dream with all of our organs- just imagine how differently Jung would interpret Pauli's dreams if he knew about this!

Seems like the article misses an interesting analog in power gating:

https://en.wikipedia.org/wiki/Power_gating

I seem to recall similar research in rats or mice that found that "sleep" states occurred randomly when awake, and slowly synchronized into moving waves of "sleep" when asleep. If I am indeed remembering correctly, then it would seem more likely that this localized sleep mechanism is shared by all mammals, including humans. I'm sure many of us have experienced cycles of awareness while supposedly fully awake as well.

I wonder if it extends to reptiles, fish, etc.

So our brains have Speedstep and are able to shut down cores to save power? :)

Seems to me that the brain is conservative on energy consumption here. The same I apply to my hobby electronic circuitry design, i.e. turn off sensory areas when not in use and back on as needed.

I would be interested to see how this relates to mental illnesses such as ADHD, schizophrnias catatonic states, and dissociative identity disorder. But maybe that will be another decade out.

This reminds me of dropout regularization - the key idea there is to randomly turn off units during training.

If our brains would work fully all the time, our head would boil and explode. I don't see how this is so new.

I am glad that functioning of the brain is understood much better. Also, this could be utilized if we could find ways to increase focus, maybe even artificially, well artificially until brain gets trained for full flow state for example.

See Carlos Casteneda and "assembling the self."

Dolphins put half their brains to sleep at a time.

Looks like my brain does full shutdown whenever there's an interview