How do random thoughts come to our mind?

[Raghav Gupta]

How we are able to recollect things and how random thoughts are generated in our mind?
Is there any specific reason?
As I can't edit my thread title, as I realize the topic should have been How random thoughts come to our mind?

 

[Greg Bernhardt]

random thoughts are generated in our mind?

First, what makes you think they are truly random?

How memory works
http://science.howstuffworks.com/life/inside-the-mind/human-brain/human-memory.htm

 

[Raghav Gupta]

First, what makes you think they are truly random?

Like suddenly a thought came to me of posting this question on PF. How it is coming to me, isn't that random?
Dreams and thought might be different.
But can we consider dreams as random thoughts?
Like when I was sleeping a dream came of dogs biting me, in reality it has not happened.
So dreams are kind of mixing our day to day things and creating random thoughts?

 

[Pythagorean]

I was reading about this a couple months ago and this thread reminded me of it. When your attention isn't focused on anything in particular, your brain gets increased activity in a region called the "default mode network". The paper I read (in nature neuroscience, I believe) went into how the modes themselves were functionally significant, so they could be involved in meandering thought processes. I can't currently find that paper, but here are some other related resources:

Thirty years of brain imaging research has converged to define the brain's default network-a novel and only recently appreciated brain system that participates in internal modes of cognition. Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment. Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system. Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others. Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems. The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation. The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations. These two subsystems converge on important nodes of integration including the posterior cingulate cortex. The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world. We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease.

The brain's default network: anatomy, function, and relevance to disease.
http://www.ncbi.nlm.nih.gov/pubmed/18400922

Thirty years of brain imaging research has converged to define the brain's default network-a novel and only recently appreciated brain system that participates in internal modes of cognition. Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment. Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system. Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others. Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems. The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation. The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations. These two subsystems converge on important nodes of integration including the posterior cingulate cortex. The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world. We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease.

The brain's default network: anatomy, function, and relevance to disease.
http://www.ncbi.nlm.nih.gov/pubmed/18400922

A series of recent empirical observations demonstrate structured activity patterns that exist during passive task states. One observation is that a network of regions, referred to as the default network, shows preferentially greater activity during passive task states as compared to a wide range of active tasks. The second observation is that distributed regions spontaneously increase and decrease their activity together within functional-anatomic networks, even under anesthesia. We believe these rest activity patterns may reflect neural functions that consolidate the past, stabilize brain ensembles, and prepare us for the future. Accumulating data further suggest that differences in rest activity may be relevant to understanding clinical conditions such as Alzheimer's disease and autism. Maps of spontaneous network correlations also provide tools for functional localization and study of comparative anatomy between primate species. For all of these reasons, we advocate the systematic exploration of rest activity.

Unrest at rest: Default activity and spontaneous network correlations
http://www.sciencedirect.com/science/article/pii/S1053811907000079

 

[Raghav Gupta]

Thanks for giving a lot of material and links, find it useful.
Just wanted to ask

Dreams and thought might be different.
But can we consider dreams as random thoughts?
Like when I was sleeping a dream came of dogs biting me, in reality it has not happened.
So dreams are kind of mixing our day to day things and creating random thoughts?

 

[Pythagorean]

We're not really sure about dreams. Dreams pull from your memory pool (so you can't dream of a dog unless you've encountered one) but there's no obvious method in the way memories are pulled into dreams and put together. There are hypotheses proposing that dreams have something to do with memory coding. You can find them easily if you look for them, as it's a sensational claim (whether true or not) so I will not post them. I will instead post evidence that suggests that dream-relevant memory coding doesn't rely on sleep [1] - well, not anymore than vital function does, and I guess that's the issue. It's a lot like arguing that oxygen is important to memory because if we don't have oxygen we die and dead people don't form memories. True, but not very useful for understanding the mechanism and potential function of dreams. So, ultimately, we need to have a clear, synthesized picture of all the processes involved. The brain is a complicated system, so instead we just have a lot of studies focusing on particular regions, particular dynamics, and particular environmental considerations. Memory is already a complicated subject - there's different kinds of memory and different brain regions associated with them and two kinds of memory can work together to form a third kind of memory (episodic and procedural memories can inform semantic memories). Further, there's always a bit of rewriting in memory recall (reconsolidation [2]) so are dreams just doing some memory writing in the usual way as with any memory recall or are they actually doing some kind of optimization on our memories?

I'm not making the argument that dreams don't have anything to do with memory, I'm fairly neutral on the subject, but I think that a basic literature search is bias towards the hypothesis that it does. So are dreams random? Maybe.

[1] http://www.sciencedirect.com/science/article/pii/S0896627304005653
[2] http://www.ncbi.nlm.nih.gov/books/NBK3905/

 

[Raghav Gupta]

Thanks for giving a detailed explanation. I will see the links some time later, though your para was descriptive and helpful.

 

[DiracPool]

How we are able to recollect things and how random thoughts are generated in our mind?
Is there any specific reason?

Random thoughts are likely generated in the "minds" of most if not all mammals in general. The real question is, what do these animals' minds do with them. The actual generation of random memories can occur spontaneously in any neural network. Energy flows throughout these networks heterogeneously in the absence of directed sensory stimuli and pseudo-randomly triggers cell-assembly attractors which generate potential thoughts via the radial spread of these excitations from their "sites of nucleation" in those cortical networks.

In non-human animals, these potential triggers typically die out in the absence of an accompanying actual sensory stimulus to reinforce their representation in the cortical behavioral driving routines. In humans, on the other hand, there is considerable evidence that these chaotic anomalies can be be caught up in a higher system that can turn them into something other than decaying neural potentials. This something other may be the "random thoughts" you are asking about.

This higher system has been identified as the Central Executive Network (CEN), and it is contrasted from the Default Mode Network (DMN) (that Pythagorean referred to above) as being the more phylogentically recent addition to the primate brain. In fact, there is a good argument that this network is unique to humans.

http://www.pnas.org/content/104/43/17146.long
http://www.ncbi.nlm.nih.gov/pubmed/25282602

 

[Raghav Gupta]

Thanks. Will look to it in detail in future as I'm not a biology student. Just had a interest in knowing these phenomena as there are many types of things in world to understand. I will now not be available frequently in this discussion. The others may continue their arguments and can debate among themselves.