Sleep and Memory Consolidation

[DrmDoc]

A recent SciShow video purports 9 Groundbreaking Discoveries About Sleep. I take issue with discovery #2, "sleep solidifies memory," wherein, purportedly, our brain organizes and consolidates our memory. The video's host says that this process occurs during non-REM sleep phases. My issue is that the brain is not organizing and consolidating memories during non-REM, which would require increased neural activity that doesn't occur. What actually occurs is something I've commented about previously regarding the removal of extracellular waste via its Glymphatic system. During non-REM, our brain flushes away extracellular toxins and waste that can impede our mental acuity. If we have stronger memories after a good sleep, its because our brain works better after it has sufficiently cleared its structure of toxic metabolic byproducts.

[Velocity_Boy]

I agree with the video and disagree with you. As do, btw, the vast majority of neurologists, psychiatrists, and other medical professionals in the sleep and dream biz.

 

Dreams are not that mysterious yo us anymore. Sadly, they don't hold the mythical and elusive inner drives and desires of the human Subconscious. Rather, as the vid posited, they are just vestigial images emitted by your brain as it embarks on its nightly process of trying to figure out where to file the past day's new memories. Picture a file clerk in a photograph warehouse with a handful of new photos his boss just gave him. And as he tries to put them in properly appropriate and accessible sub file folders. He also is tasked with discerning which photos...Memories to you...To throw away and which to keep.

 

That's it.

 

A closing caveat...I use the term days and nights assuming the dreamer is typical in that he had a diurnal biorythym, and thus sleeps at night. But it matters not to the brain, as it will just do it's filing duties the following day, should the host organism be nocturnal.

 

Hope this helps.

 

Hmm.just occurred to me this is the second time today I've explained the dreaming process. LOL

[CharonY]

Any source claiming a clear understanding of the process(es) is almost certainly wrong. Either that, or simplified to a degree that it does not actually answer any questions. Roughly two things are assumed. The first is that sleep is somehow required for memory consolidation (whch is failry certain as it goe) and the is that the there are different contributions of REM and slow-wave sleep (SWS) to the process.

After that it gets very speculative. A common hypothesis is that SWS is important for the formation of declarative memories, whereas REM has a stronger contribution to non-declarative memory. This would run counter to a merely supplemental role of non-REM sleep.

And there is quite a bit of experimental data to support the role of SWS for this process. But clearly, far more research is needed to actually figure out mechanisms and form a coherent theoretical framework.

[Velocity_Boy]

Any source claiming a clear understanding of the process(es) is almost certainly wrong. Either that, or simplified to a degree that it does not actually answer any questions. Roughly two things are assumed. The first is that sleep is somehow required for memory consolidation (whch is failry certain as it goe) and the is that the there are different contributions of REM and slow-wave sleep (SWS) to the process.

After that it gets very speculative. A common hypothesis is that SWS is important for the formation of declarative memories, whereas REM has a stronger contribution to non-declarative memory. This would run counter to a merely supplemental role of non-REM sleep.

And there is quite a bit of experimental data to support the role of SWS for this process. But clearly, far more research is needed to actually figure out mechanisms and form a coherent theoretical framework.

But in neurology we do have the basic mechanisms the brain utilizes during dream states pretty much down pat. I'm not sure how close you've been following the neurology of sleep and dreaming of late, but significant advances have been made over the past five years or so.

 

And it is indeed broken down far beyond your do called declarative and non d. Memories. We go down to the neuronal and neurotransmitter level.

 

But the basic and metaphorical explanation I gave in my OP is very accurate. Enough for any layman. Even for medical professionals who aren't directly working in dream neurology. My filing system analogy with the photos is a good one. I welcome any psych or neuro pro reading this to deny that. At the risk of sounding arrogant.

 

We just know how dreams are generated. That's it. If you wish to get a deeper explanation you might enjoy this......

 

 

 

http://dreamstudies.org/2010/01/07/neuroscience-of-dreams/

Edited April 19, 2017 by Velocity_Boy

[CharonY]

I think we have a very different definition to what "down pat" means. Bits and pieces, yes. Some neuronal structures, too. While I am not expert in this area, I do come across neurobiological reviews fairly often and nothing in the recent years have suggested that there is a full understanding of the mechanisms from the cellular process to full physiological consequences (i.e. memory consolidation). In fact, a tonne is still missing to fully understand the concept of memory itself. What you may be thinking about is some of the basic processes that happen that are either associated or are a consequence of the respective sleep phases (such as controlled activation and deactivation of certain brain areas). But how precisely the various functions lead to memory consolidation is far from known. Rather, it is known that certain disruptions in those pattern can interrupt the process somehow.

 

However, if you came across studies that have those details, I would be more than happy to read them. However, the link you provided is not such an example. It names a conceptional model of uncertain usefulness (as it lack quantitative properties) and not much else. Having hypotheses (and there are several of them around) is not quite the same as having it down pat, which I interpret as actually understanding the mechanisms.

[DrmDoc]

I agree with the video and disagree with you. As do, btw, the vast majority of neurologists, psychiatrists, and other medical professionals in the sleep and dream biz.

 

Unfortunately, you and they are absolutely wrong because there's not a single shred of solid neurological evidence for memory consolidation in sleep. Admittedly, there's a plethora of legitimate study and test results that do reveal our memory and mental acuity as functionally far superior particularly after the non-REM stages of sleep. However, as CharonY so aptly conveyed, "nothing in the recent years have suggested that there is a full understanding of the mechanisms from the cellular process to full physiological consequences (i.e. memory consolidation)", particularly in sleep...but then, there are those pesky results and how we should interpret them isn't there?.

 

Although the efficacy of non-REM sleep in restoring mental acuity is legitimate, that legitimacy is undermined by the absence of some clearly defined or cogently relevant neurological evidence. Well, there is such evidence that provides a defined and cogent explanation for our enhanced memory and acuity after non-REM and that evidence has nothing to do with some memory consolidation process in sleep. That evidence is provided by the connection between Alzheimer and our Glymphatic system.

 

Our brain's normal processes produce a toxic metabolic byproduct (amyloid-beta) that is known to accumulate plaque in the brains of Alzheimer patients who suffer debilitating memory loss. During non-REM sleep, this memory debilitating peptide (amyloid-beta) is removed from our brain via its glymphatic process. Rather than some memory or neural consolidation process as many believe, it's the removal of this amyloid peptide and other extracellular waste that enhances our neural connectivity and, effectively, our memory potential and mental acuity.

 

Dreams are not that mysterious yo us anymore. Sadly, they don't hold the mythical and elusive inner drives and desires of the human Subconscious. Rather, as the vid posited, they are just vestigial images emitted by your brain as it embarks on its nightly process of trying to figure out where to file the past day's new memories. Picture a file clerk in a photograph warehouse with a handful of new photos his boss just gave him. And as he tries to put them in properly appropriate and accessible sub file folders. He also is tasked with discerning which photos...Memories to you...To throw away and which to keep.

 

 

Although I've extolled dreaming as an extraordinary experience, I would never assert that experience as mysterious. The mystery for me was lost in my early youth and buried by neuroscience ever since. Neuroscience has informed me that the brain doesn't produce a "Subconscious" and that dreams aren't as many believe or as the video describes. As I complete my fourth decade of indulging my interest in mind and consciousness, neuroscience informs me that our brain function produces just two measurable states (conscious and unconscious) suggestive of activation and mentation. Rather than a mind or state, subconscious is an influence our brain either produces or is affected by. Actual brain states like coma and dreaming are a subset of our brain's unconscious functions. As I so frequently commented, the distinction between unconscious and subconscious is analogous to a person and a package. In that analogy, unconscious identifies the persons while subconscious identifies the package he either receives or delivers.

 

Regarding the nature of dreams and your link to an Allan Hobson article, Allan is a well respected, Harvard professor learned in the neuroscience of the dreaming brain for many years...and...I think he's wrong on several issues. Here's an example from your article link:

 

Hobson’s discovery of the role of neurotransmitters in dreaming has stimulated robust research into the biochemistry of consciousness and revolutionized the way that mental illness is conceptualized in psychiatry. REM dreaming is characterized by low serotonin levels and high acetylcholine levels, which may explain why dreams are so hard to remember: they are never encoded in short-term memory in the first place. When we wake up, serotonin floods the brain and our dream experiences from just a moment before are carried away by the tide.

 

 

He was looking for neurological reasons why dreams are hard to remember and, correctly, investigated neurological and neurochemical distinctions between the waking and dreaming states of brain function. His serotonin conclusion is flawed, in my view, for a couple of reasons. First, the idea that serotonin disrupts memory formation after dreaming suggests that serotonin should also have the same effect during wakeful experience since our waking-state brain is continually bathe in this neurochemical. We actually remember our experiences from day-to-day quite well with increased serotonin. Second, Prof. Hobson didn't appear to consider the evolved nature of memory and its impact on his findings.

 

When we think about what may have led to the evolution of memory as one of humanity's most significant survival tools, we should find that real physical/material experience was likely the most compelling impetus for that adaptation. Without question, memory evolved concurrent with sensory experiences that had a real physical/material impact on the survival of ancestral animals. Consequently, as I have frequently commented, our brains have evolved the ability to detect and distinguish the sensory distinctions of true physical/material reality. That ability is supported by transient hypofrontality in sleep and cortical dependency on subcortical neural input as suggested by decorticate studies. Our dream perceptions aren't real physical/material experiences in true reality and, therefore, are difficult to remember because of the evolved nature of memory. If we are able to remember even a little about our dreams, its because of the subtle and subdue real physical perceptions incorporated into dream content. For example, dreaming about running incorporates increased physical respiration in sleep, which can be detected by our brain amid dreaming and lead to an enhanced memory of that dream experience.

Edited April 19, 2017 by DrmDoc

[Function]

Any source claiming a clear understanding of the process(es) is almost certainly wrong. Either that, or simplified to a degree that it does not actually answer any questions.

 

Emerson Pugh said: "If the brain were so simple that we could understand it, we would be so simple that we couldn't."

[DrmDoc]

 

Emerson Pugh said: "If the brain were so simple that we could understand it, we would be so simple that we couldn't."

 

Unlike CharonY, I believe that there are sources that do clearly explain certain memory phenomena simply and neatly particularly amid sleep. Although I agree that our brain isn't simple, I don't believe its complexity is beyond our ability to decipher or understand.

[Function]

 

Unlike CharonY, I believe that there are sources that do clearly explain certain memory phenomena simply and neatly particularly amid sleep. Although I agree that our brain isn't simple, I don't believe its complexity is beyond our ability to decipher or understand.

 

I am consciously awaiting the day that Professor Steven Laureys and his Coma Science Group (or the hell, any neuroscientist) gives the great breakthrough in the understanding of our consciousness and conscience, and our understanding of our existance.

[DrmDoc]

 

I am consciously awaiting the day that Professor Steven Laureys and his Coma Science Group (or the hell, any neuroscientist) gives the great breakthrough in the understanding of our consciousness and conscience, and our understanding of our existance.

 

Overall, I think evolution pretty much explains our existence. As for consciousness, brain evolution provided me with that particular breakthrough moment. Functionally, from spinal cord to cortex, our brain contiguously reveals its evolutional steps. From its ancestral notochord emergence to its most recent cerebrum development, our brain's functional construct suggests quite a lot about how it evolved consciousness--in my opinion.

[goldglow]

A recent SciShow video purports 9 Groundbreaking Discoveries About Sleep. I take issue with discovery #2, "sleep solidifies memory," wherein, purportedly, our brain organizes and consolidates our memory. The video's host says that this process occurs during non-REM sleep phases. My issue is that the brain is not organizing and consolidating memories during non-REM, which would require increased neural activity that doesn't occur. What actually occurs is something I've commented about previously regarding the removal of extracellular waste via its Glymphatic system. During non-REM, our brain flushes away extracellular toxins and waste that can impede our mental acuity. If we have stronger memories after a good sleep, its because our brain works better after it has sufficiently cleared its structure of toxic metabolic byproducts.

Watched the video and found it quite interesting, but Shakespeare put it better in MacBeth, Act 2, Scene 2:

 

".... Sleep, that knits up the ravell'd sleave of care,

The death of each day's life, sore labours bath,

Balm of hurt minds,great nature's second course,

Chief nourisher in life's feast. "

 

Could we say that the brain " defragments " during sleep?

[Danijel Gorupec]

What actually occurs is something I've commented about previously regarding the removal of extracellular waste via its Glymphatic system. During non-REM, our brain flushes away extracellular toxins and waste that can impede our mental acuity. If we have stronger memories after a good sleep, its because our brain works better after it has sufficiently cleared its structure of toxic metabolic byproducts.

So, why can this extracellular toxin removal process only happen during unconscious state? Accidental evolutionary path or deeper reasons?

[DrmDoc]

Could we say that the brain " defragments " during sleep?

 

I think the process is more like the removal of obstructions that impede connectivity between neural chains of memory rather than a type of reorganization.

 

So, why can this extracellular toxin removal process only happen during unconscious state? Accidental evolutionary path or deeper reasons?

 

It happens during the conscious state as well but this waste removal process is likely more efficient when the brain is unconscious and not as actively producing cell waste as it does during its waking-state. The evolved nature of sleep primarily regards the efficient mediation of our metabolism during periods of rest and between feeding cycles. During the sleep process, the brain doesn't consume as much energy and its volume actually shrinks. This suggests that the brain doesn't produce as much cell waste and has more time with less constricted pathways to flush away toxic byproducts.

[goldglow]

Thanks, You mentioned earlier the 2 measurable states of the brain: conscious and unconscious, with the subconcious acting as a two-way path between the 2 states, if i have understood correctly. I'd like to ask: do you regard the unconcious as a personal " possession ", or is it the Collective Unconscious that C.G. Jung spoke of - a sort of cloud memory - identical to Rupert Sheldrake's " Morphic Resonance ", or even what ancient mystics called the " Akashic Record "?

[DrmDoc]

Thanks, You mentioned earlier the 2 measurable states of the brain: conscious and unconscious, with the subconcious acting as a two-way path between the 2 states, if i have understood correctly. I'd like to ask: do you regard the unconcious as a personal " possession ", or is it the Collective Unconscious that C.G. Jung spoke of - a sort of cloud memory - identical to Rupert Sheldrake's " Morphic Resonance ", or even what ancient mystics called the " Akashic Record "?

 

Jung didn't have access to the kind of neuroscience we enjoy presently and his ideas were heavily influenced by his religious upbringing. What Jung concluded as evidence of some Unconscious Collective was merely evidences of the extraordinary perceptual capabilities of our unconscious mind individually. Individually, our unconscious brain function is capable of extraordinary feats of perception and analysis that can give the appearance of otherworldly insight when it is merely insight derived from an altered state of awareness and perceptual experience in brain function. It's not about accessing some cloud collective or mystical record, it's about accessing, perceiving, and assessing previously experienced but consciously ignored perceptions. Although our conscious mental and perceptual processes may be unremarkable, our unconscious mind is extraordinarily eidetic and savant-like in nature--in my opinion.

Edited April 29, 2017 by DrmDoc

[goldglow]

Had to look-up " eidetic, " as in " eidetic memory. " As i now know, this explains why Mozart, for example, was able to have complete recall of complex orchestral and choral music after only one hearing, and how Kim Peek, ( the person who was the real-life inspiration for the " Rain Man " movie ) was able to perform astonishing feats of memory despite - or perhaps because of - having been born with FG Syndrome. Thanks.

 

 

Definition of " eidetic ": "......marked by or involving extraordinarily accurate and vivid recall, especially of

visual images. " ( Merriam-Webster dictionary. )

Edited April 29, 2017 by goldglow

[DrmDoc]

Had to look-up " eidetic, " as in " eidetic memory. " As i now know, this explains why Mozart, for example, was able to have complete recall of complex orchestral and choral music after only one hearing, and how Kim Peek, ( the person who was the real-life inspiration for the " Rain Man " movie ) was able to perform astonishing feats of memory despite - or perhaps because of - having been born with FG Syndrome. Thanks.

 

 

Definition of " eidetic ": "......marked by or involving extraordinarily accurate and vivid recall, especially of

visual images. " ( Merriam-Webster dictionary. )

 

Which explains why accessing the unconscious via hypnosis can sometimes elicit forgotten details of prior experiences.

[goldglow]

Yes. Thanks. I wouldn't dream of asking for dream-interpretation, ( sorry for that feeble joke! ) , but i am interested in something i can't explain for myself: i very often dreamed of being in a brightly lit library with a staircase leading to other floors above, but, the last time i had this dream, the library was in darkness and the stairway was blocked. Without trying to interpret anything , what could have actually taken place in the unconscious, if that's the case, to change the old dream, when i can think of nothing in my daily life, ( same old same old ), that could have caused this alteration in the " package " received in the dream, nor point to any great revelation from remembering the dream?

[DrmDoc]

Yes. Thanks. I wouldn't dream of asking for dream-interpretation, ( sorry for that feeble joke! ) , but i am interested in something i can't explain for myself: i very often dreamed of being in a brightly lit library with a staircase leading to other floors above, but, the last time i had this dream, the library was in darkness and the stairway was blocked. Without trying to interpret anything , what could have actually taken place in the unconscious, if that's the case, to change the old dream, when i can think of nothing in my daily life, ( same old same old ), that could have caused this alteration in the " package " received in the dream, nor point to any great revelation from remembering the dream?

 

I've forgotten more thing about dreaming than some professed experts claim to understand and your dream experience isn't very complex from my perspective. The key to understanding your experience resides in an empirical truth, which is dreaming regards a mental reality rather than one that is physically or materially real. Empirically, dreaming is an immersive mental experience and, therefore, all aspects of that experience regards something that is mental in nature. As an immersive mental experience, our actual experience of being physically at rest or asleep in material reality doesn't reach our awareness the way it does when we are fully awake. Consequently, our dream perceptions are incongruent with our actual physical experience of being at rest or asleep. It's that incongruence that makes our dream experiences more difficult to recall in detail than those experiences we have that are congruent with our actual physical/material perceptions and consequences.

 

Unfortunately, far too many of us don't think there's value in any efforts to understand an experience that doesn't appear to have any real physical/material impact on our reality. I believe differently because I understand that impact regards our mental reality, which is equally as relevant and important to our health and overall life experience. To understand the unconscious implications of your dream, you'll have to translate its content first. A library, for example, is an environment of collective works of knowledge and, if this were my dream, It would likely reflect my thoughts on such a mental environment. The darkness of this environment would regard my thoughts on its less than illuminating quality. Blocked stairs leading upward would regard my thoughts on how I perceive some barrier to the steps I might take to reach some higher level of edification within that environment. Overall, it would be clear to me that this dream experience is a reflection of my frustration or disappointment in some experience that should be more illuminating, mentally, than it seems to be. Our repeated frustration and disappointment with certain conscious experiences can and do manifest as recurring dreams.

 

Dreams tend to convey something we already know but in ways that can be perceptually clear. I hope this helps.

Edited April 30, 2017 by DrmDoc

[goldglow]

It helps a great deal, and definitely strikes a chord. Thank you. I'll be fascinated to see what happens if i ever go back to that library!