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#1 ThoughtOnFire

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Posted 23 June 2017 - 11:43 AM

Default mode network

 

In neuroscience, the default mode network (DMN), also default network, or default state network, is a network of interacting brain regions known to have activity highly correlated with each other and distinct from other networks in the brain.[3]

The default mode network is most commonly shown to be active when a person is not focused on the outside world and the brain is at wakeful rest, such as during daydreaming and mind-wandering. But it is also active when the individual is thinking about others, thinking about themselves, remembering the past, and planning for the future.[3][4] The network activates "by default" when a person is not involved in a task. Though the DMN was originally noticed to be deactivated in certain goal-oriented tasks and is sometimes referred to as the task-negative network,[5] it can be active in other goal-oriented tasks such as social working memory or autobiographical tasks.[6] The DMN has been shown to be negatively correlated with other networks in the brain such as attention networks.[7] Thinking about others also could include guessing their thoughts, emotions, and psychological motivations.

Evidence has pointed to disruptions in the DMN with people with Alzheimer's and autism spectrum disorder.[3]

 

Function[edit]

The default mode network is known to be involved in many seemingly different functions:

It is the neurological basis for the self:[8]

  • Autobiographical information: Memories of collection of events and facts about one's self
  • Self-reference: Referring to traits and descriptions of one's self
  • Emotion of one's self: Reflecting about one's own emotional state

Thinking about others:[8]

  • Theory of Mind: Thinking about the thoughts of others and what they might or might not know
  • Emotions of other: Understanding the emotions of other people and empathizing with their feelings
  • Moral reasoning: Determining just and unjust result of an action
  • Social evaluations: Good-bad attitude judgments about social concepts
  • Social categories: Reflecting on important social characteristics and status of a group

Remembering the past and thinking about the future:[8]

  • Remembering the past: Recalling events that happened in the past
  • Imagining the future: Envisioning events that might happen in the future
  • Episodic memory: Detailed memory related to specific events in time
  • Story comprehension: Understanding and remembering a narrative

The default mode network is active during passive rest and mind-wandering.[3] Mind-wandering usually involves thinking about others, thinking about one's self, remembering the past, and envisioning the future.[8]Electrocorticography studies (which involve placing electrodes on the surface of epileptic patient's brains) have shown the default mode network becomes activated within an order of a fraction of a second after participants finish a task.[9]

Studies have shown that when people watch a movie,[10] listen to a story,[11] or read a story,[12] their DMNs are highly correlated with each other. DMNs are not correlated if the stories are scrambled or are in a language the person does not understand, suggesting that the network is highly involved in the comprehension and the subsequent memory formation of that story. The DMN is shown to even be correlated if the same story is presented to different people in different languages,[13] further suggesting the DMN is truly involved in the comprehension aspect of the story and not the auditory or language aspect.

The default mode network has shown to deactivate during external goal-oriented tasks such as visual attention or cognitive working memory tasks, thus leading some researchers to label the network as the task-negative network.[5] However, when the tasks are external goal-oriented tasks that are known to be a role of the DMN, such as social working memory or an autobiographical task, the DMN is positively activated with the task and correlates with other networks such as the network involved in executive function.[6]

 

Pathophysiology[edit]

The default mode network has been hypothesized to be relevant to disorders including Alzheimer's diseaseautismschizophreniadepressionchronic pain and others.[3]

People with Alzheimer's disease show a reduction in glucose (energy use) within the areas of the default mode network.[3] These reductions start off as slight decreases in mild patients and continue to large reductions in severe patients. Surprisingly, disruptions in the DMN begin even before individuals show signs of Alzheimer's disease.[3] Plots of amyloid-beta, which is thought to cause Alzheimer's disease, show the buildup of the protein is within the DMN.[3] This prompted Randy Buckner and colleagues to propose the high metabolic rate from continuous activation of DMN causes more amyloid-beta protein to accumulate in these DMN areas.[3] These amyloid-beta proteins disrupt the DMN and because the DMN is heavily involved in memory formation and retrieval, this disruption leads to the symptoms of Alzheimer's disease.

DMN is thought to be disrupted in individuals with autism spectrum disorder.[3] These individual are impaired in social interaction and communication which are tasks central to this network. Studies have shown worse connections between areas of the DMN in individuals with autism, especially between the mPFC (involved in thinking about the self and others) and the PCC (the central core of the DMN).[18][19] The more severe the autism, the less connected these areas are to each other.[18][19] It is not clear if this is a cause or a result of autism.

Lower connectivity was found across the default network in people who have experienced long term trauma, such as childhood abuse or neglect, and is associated with dysfunctional attachment patterns. Among people experiencing posttraumatic stress disorder, lower activation was found in the posterior cingulate gyrus compared to controls.[20] Hyperconnectivity of the default network has been linked to rumination in depression[21] and chronic pain.[22]



#2 ThoughtOnFire

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Posted 23 June 2017 - 11:44 AM

Possible correlation to DP/DR?



#3 Broken

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Posted 25 June 2017 - 04:40 PM

Interesting that I was reading about this the other day. DMN is correlated with mind-wandering meditations like ACEM and others, but also hypothesised to be involved with processing trauma. Mind wandering activates the medial temporal lobe (smaller in DP in one study I read) and this area specifically processes trauma... or so the theory goes. I think my mind (cant speak for other DP'ers) is overly focused which I've said before is probably over-activating the executive functioning network.. which may overactivate the parietal lobe that is larger in one DP study and implicated in focusing attention... its a far reach, but mind wandering meditation has been very helpful recently. So my over active mind focuses to stop my mind 'wandering' over to repressed memories and supressed things.. it's almost as if there is this subconscious strain going on keeping me from opening a certain window in my mind.. because I have been there before and I didnt like what I saw. So I OVERLY focus on what I am doing which keeps this tunnel vision literally and metaphorically. When I let my mind wander and calm and slow down.. it helps



#4 Broken

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Posted 21 September 2017 - 09:24 AM

I think this is quite relevant to my recent thoughts on DPD. The DMN is where the mind wanders and does it's own thing. No task or agenda, nothing to do. Just rest and effortless wandering. 

 

Executive function network; 

 

The dorsolateral prefrontal cortex (DLPFC) is involved with "on-line" processing of information such as integrating different dimensions of cognition and behaviour.

The anterior cingulate cortex (ACC) is involved in emotional drives, experience and integration

The orbitofrontal cortex (OFC) plays a key role in impulse control, maintenance of set, monitoring ongoing behaviour and socially appropriate behaviours

 

DLPFC magnetic stimulation DPD study. Low hertz stimulation (decrease blood flow) of right DLPFC (associated with negative emotion), and high hertz stimulation (increase blood flow) of left DLPFC : https://www.ncbi.nlm...pubmed/28291040

 

ACC increased blood flow associated with increased DP (old study but meh.. still relevant). As I understand it DPD has higher blood flow in ACC UNTIL there is emotional context and blood flow decreases: https://www.ncbi.nlm...pubmed/10442442

 

OFC- The human OFC is among the least-understood regions of the human brain; but it has been proposed that the OFC is involved in sensory integration (unknown really, also involved with reward during tasks).

 

Default mode network:

 

This would be a large list, as also there are many things potentially done in kind wandering such as; Information regarding the self, Thinking about others, Autobiographical memory and future simulations, as well as trauma processing (which can involve any of these things). 

Sleep deprivation results in a decrease in connectivity within the DMN - for me this is chicken and egg but I never get a good nights sleep. Whether that is caused by DP or bad sleep caused DP is unsure. But bad sleep did come first but was a long term problem.

 

Now to the point. My mind is completely obsessed with recovering from this. Which I believe over activates my executive functions, to the point now where I believe they are probably overactive to the point I cannot switch them off. This is either because of the DP coming along and me being obsessed with recovery. It is almost as though my brain had to maintain DP to study it and find out what it was in order to get rid of it. Or the other option is, that during mind wandering something was remembered. A trauma that I cannot now access in order to protect my sense of self. So my mind doesn't enter that 'zone' of consciousness in order to net get re-retraumatised. 

 

If I could sum this all up, I think I need some form of CBT where I rewrite my entire belief system about this. In 3 points they would be:

 

1) All symptoms are anxiety.

2) There is nothing I can do to get better. I need rest not obsession

3) There is no therapy, medication or supplement that will help.

 

And whenever my mind veers away from those points I need to bring myself back to them. With time they will help me drop the topic and they will be naturally more incorporated into my own way of thinking. And with less effort to 'get better' the fear of not recovering or finding 'the cure' will drop away as I am not reinforcing that fear every god damn minute of the day



#5 Broken

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Posted 27 September 2017 - 09:26 AM

Also of relevance is the SALIENCE network- makes you care about things, makes you do things and have motivation. This is primarily the ACC and anterior insula, both of which are heavily involved in DPD. Now, SKUNK that is high thc and low cbd causes depersonalization symptoms in healthy individuals as it dissrupts the salience network. Interestingly HASH which has lower thc and higher cbd levels (ratio 3%thc / 3%cbd) DOES NOT do this. So, it would seem high thc levels are the enemy to this network.

 

If you are interested, 54minutes into this documentary on marijuana talks about this. How hash doesnt disrupt the salience network but skunk did.... so. A theory of mine is that THC has caused some (mine and others) dpd to develop. I have ordered some  CBD and tried it before.. the issue is, it would cost a LOT of money in order to get this drug to a therapeutic value. But none the less it could help...

 

I am also still developing my own tailored form of CBT if you will. Basically telling myself that all physical, mental and emotional symptoms are signs of a tired body and mind. That is all. That they are signs of healing not me going crazy. And that I need to rest. This has been of some benefit, but will take a lot of time to rewire and change my entire thought/belief system around this condition



#6 Broken

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Posted 07 October 2017 - 12:17 PM

https://www.google.c...yAjHGYCdsmMK2lx

Salience network (anterior cingulate and insula) and the effect of CBD and THC

#7 bouquet

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Posted 08 October 2017 - 11:51 AM

Interesting read,thank you for sharing these. Would you say that the more legal marijuana becomes and the more research being conducted, the more chances there are for medical treatment to be developed to eliminate negative effects of high THC and reverse DP/DR effects as well?

#8 Broken

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Posted 08 October 2017 - 12:56 PM

No worries, I sure find it interesting and very relevant. Shame not many others do! lol I can understand it though, I used to be very against this argument when I read about it years ago. It seems insane to suggest to take more of what got me into this mess. But channel 4 had a great documentary called 'drugs live' where people took hash, skunk and placebo. The difference of the effects and the science behind it on that show completely changed my opinion. CBD and THC are VERY different drugs.

 

Absolutely. My position on marijuana has yo-yoed over the years. I am now very pro legalisation and education. High THC strains are very damaging and cause psychosis and actually degrade the connection between the two hemispheres of the brain (the corpus callosum). But CBD really protects the over stimulating effects of THC and seems to prevent that... I say 'seems' as there is little science on this at the moment, but it all suggests this. 

 

The science of DP/DR is still wishy washy and weak. It seems the high effects of THC cause DP symptoms in some which could be due to CB1 receptors or another mechanism, perhaps downstream effecting dynorphin (kappa ligand/agonist) release.. again kappa ligands/agonists seem to create DP symptoms. I don't know what caused my DP unfortunately, but it started with a panic attack from skunk after EATING it! (stupid idea). And then I smoked as the high takes 2-3hours to hit after eating it... so I probably had a lot of THC in the system and low CBD. Also, my 'highs' were always DP symptoms; things looked unreal, detached, emotionless, zoned out, foggy mind etc. This is what I thought 'being high' was.. if educated on the risks I would have stopped then. I don't think a normal high is dissociation. Or not to the extent I had.

 

Now to what is happening now. I take 5% CBD approx 15 drops a day which would be approx 15mg. It takes about 6 days to stabilise in amount in the blood by my calculation. Also, some science seems to say the metabolites of CBD further aid it's therapeutic effect.. it has been about 10/11days since I started and today it really seems to be taking effect. I feel better and my sleep quality has improved a lot the last 2 days. My DR seemed a slight amount better today and my mood is also better. And also generally more relaxed. The issue is, people, as I did, take the first dose, get a dramatic effect that is relaxing and great. But this dies down and is not experienced with the same force as the first dose, so people believe they have 'built tolerance'... I think the doses have to be continued daily without fail to build it up in the blood. I'm nowhere near writing a recovery story, but of the endless list of supplements I have tried, this one I will be sticking to for sure. Another note is my appetite is increasing, positive for me as I don't eat nearly enough. 



#9 bouquet

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Posted 08 October 2017 - 04:04 PM

"....yo-yoed over the years" haha, I totally agree with you,it's been the same experience for me,too!!

I'm sorry to hear what you went/go through, and hope you feel better day by day!! I also have marijuana-induced derealization,I woke up one day a few weeks after the first time I have ever used marijuana, to see things in 2D and as if my head is not in its previous position! My eyes also seems to not focus right especially when I wake up but I believe they are all related...feels like a mild high...also the symptoms came together with an unusual stiff neck, where the neck meets the body,(not painful but incredibly stiff somehow),so the only explanation I came up with after looking through the internet has been Derealization!

I read about CBD treatment but I never tried it,as I was not sure whether it would work but just like you said,even the fact that it gives relief for anxiety might work in the long run,thank you very much for the suggestion.

All I do in the mean time has been not really thinking about it and keeping myself busy,I mean We all need to consider worst case scenarios-at least We can feel, touch, laugh and move around:) it's just that it feels like a good read when I come up with the research,I'm really looking forward to new research regarding the impact of CBD and THC. I mean they MUST come up with a medical solution to stop this as it is becoming a more global problem now and the more young people use it,the more they will experience it! I read that it even happens with some people who are sensitive to little amounts of THC.

Please please let us know how you're doing with the CBD therapy and post anything research related if you may,I'm glad to hear your appetite is coming back,in the mean time don't forget to fill your days with laughter as it will make you feel wayyy better!:) I believe We will beat this thing with enough faith in ourselves, our surroundings and god perhaps!:)

#10 nickcb96

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Posted 09 October 2017 - 08:51 AM

No worries, I sure find it interesting and very relevant. Shame not many others do! lol I can understand it though, I used to be very against this argument when I read about it years ago. It seems insane to suggest to take more of what got me into this mess. But channel 4 had a great documentary called 'drugs live' where people took hash, skunk and placebo. The difference of the effects and the science behind it on that show completely changed my opinion. CBD and THC are VERY different drugs.

Absolutely. My position on marijuana has yo-yoed over the years. I am now very pro legalisation and education. High THC strains are very damaging and cause psychosis and actually degrade the connection between the two hemispheres of the brain (the corpus callosum). But CBD really protects the over stimulating effects of THC and seems to prevent that... I say 'seems' as there is little science on this at the moment, but it all suggests this.

The science of DP/DR is still wishy washy and weak. It seems the high effects of THC cause DP symptoms in some which could be due to CB1 receptors or another mechanism, perhaps downstream effecting dynorphin (kappa ligand/agonist) release.. again kappa ligands/agonists seem to create DP symptoms. I don't know what caused my DP unfortunately, but it started with a panic attack from skunk after EATING it! (stupid idea). And then I smoked as the high takes 2-3hours to hit after eating it... so I probably had a lot of THC in the system and low CBD. Also, my 'highs' were always DP symptoms; things looked unreal, detached, emotionless, zoned out, foggy mind etc. This is what I thought 'being high' was.. if educated on the risks I would have stopped then. I don't think a normal high is dissociation. Or not to the extent I had.

Now to what is happening now. I take 5% CBD approx 15 drops a day which would be approx 15mg. It takes about 6 days to stabilise in amount in the blood by my calculation. Also, some science seems to say the metabolites of CBD further aid it's therapeutic effect.. it has been about 10/11days since I started and today it really seems to be taking effect. I feel better and my sleep quality has improved a lot the last 2 days. My DR seemed a slight amount better today and my mood is also better. And also generally more relaxed. The issue is, people, as I did, take the first dose, get a dramatic effect that is relaxing and great. But this dies down and is not experienced with the same force as the first dose, so people believe they have 'built tolerance'... I think the doses have to be continued daily without fail to build it up in the blood. I'm nowhere near writing a recovery story, but of the endless list of supplements I have tried, this one I will be sticking to for sure. Another note is my appetite is increasing, positive for me as I don't eat nearly enough.


Would you have to of gotten DP from marijuana to benefit from CBD? I got mine from panic/stress and wanted to try it.

#11 Broken

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Posted 09 October 2017 - 09:06 AM

I think if it was triggered specifically by skunk it is more likely to help... that's just my hunch, it isn't based on anything. As far as CBD is concerned it is safe and effective with helping anxiety. Few side effects for me only positives. The only thing I have read is it can reduce sperm mobility.. at the moment this isn't a problem for me. I would say give it a go.. and remember that from my experience the first dose had a huge effect and then nothing.. it took ten days for more positives to be felt by me. Take it in the morning and evening EVERY day for a month before you judge. I feel generally more mellow and my sleep is improving day by day. It takes time to build up in the system as it has a long half life so don't be disheartened if it stops working after that first day



#12 Billy D.P.

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Posted 26 May 2018 - 11:14 AM

Just heard this on the Joe Rogan podcast and felt compelled to share. If you go to the 36 minute mark there's an interesting discussion about the Default Mode Network and many of the symptoms Pollan mentions are correlated with DP. We always talk about feeling disconnected and given how many people get DP after drug use I'm wondering if DP is largely a malfunctioning of the DMN, either by way of neuronal damage or simply an inability to restart for whatever reason. Anyway, this whole interview is interesting but I found the part about the DMN especially intriguing with regards to DP. 

 






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