Brain study suggests consciousness a matter of optimal degree of connectedness in neural network

January 27, 2016 by Bob Yirka, Medical Xpress report
brain
White matter fiber architecture of the brain. Credit: Human Connectome Project.

(Medical Xpress)—A team of European researchers has found evidence that suggests that human consciousness is a state where the neural network that makes up the brain operates at an optimal degree of connectedness. In their paper published in Journal of the Royal Society Interface, the team describes their study of the human brain using volunteers undergoing fMRI scans while succumbing to the effects of an anesthetic that caused them to lose consciousness, and what was revealed in reviewing the scan data.

Human beings, when awake, exist in a state of that is uniquely difficult to define. Scientists try by agreeing that it is the ability to have subjective experiences and to enjoy a first-person perspective on the "reality" of the world. But that does not explain the voice that is our own self, nor the varying degrees of consciousness, such as the differences between being asleep, versus partially awake, versus being completely unconscious. In this new effort, the researchers sought to learn more about the state that exists in the mind when consciousness occurs by enlisting the assistance of 12 volunteers who agreed to be made unconscious by the drug propofol, normally used to put people under during surgical procedures (and notably, also the drug that led to the death of singer Michael Jackson) while undergoing fMRI scans.

Scientists (and surgeons) believe that propofol causes people to become completely unconscious, which by definition would mean to become incapable of processing thoughts. The brain should not be able to process pain signals, for example, thus making surgery a pain free experience. To gain a better perspective on the various states of consciousness, the team watched blood flow changes in the brains of the volunteers as they moved from a conscious state, to unconsciousness and then back to consciousness.

In studying the scans, the researchers found that when the volunteers were conscious, there was what they describe as "a flurry of ever-changing activity," with a lot of activity between the various neural networks. In contrast, they found that while unconscious, the brains of the volunteers were engaged in far less interconnectivity and were less variable over time.

These findings, the team suggests, show that consciousness in the brain is merely, in a physical sense, a state where there is an optimal level of connectedness.

Explore further: Scientists find way to predict who is likely to wake up during surgery

More information: Enzo Tagliazucchi et al. Large-scale signatures of unconsciousness are consistent with a departure from critical dynamics, Journal of The Royal Society Interface (2016). DOI: 10.1098/rsif.2015.1027

Abstract
Loss of cortical integration and changes in the dynamics of electrophysiological brain signals characterize the transition from wakefulness towards unconsciousness. In this study, we arrive at a basic model explaining these observations based on the theory of phase transitions in complex systems. We studied the link between spatial and temporal correlations of large-scale brain activity recorded with functional magnetic resonance imaging during wakefulness, propofol-induced sedation and loss of consciousness and during the subsequent recovery. We observed that during unconsciousness activity in frontothalamic regions exhibited a reduction of long-range temporal correlations and a departure of functional connectivity from anatomical constraints. A model of a system exhibiting a phase transition reproduced our findings, as well as the diminished sensitivity of the cortex to external perturbations during unconsciousness. This framework unifies different observations about brain activity during unconsciousness and predicts that the principles we identified are universal and independent from its causes.

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BobSage
2 / 5 (4) Jan 27, 2016
"...consciousness in the brain is merely..." Good demonstration of the unique blindness of scientists to the nature of consciousness.

At the risk - no the certainty - of offending 99% of scientists, I will reveal to your unseeing eyes the truth: there is no material universe. Consciousness is all there is, period. All your experiments are being done on yourselves.

thefurlong
5 / 5 (4) Jan 27, 2016
At the risk - no the certainty - of offending 99% of scientists,

"I am going to make to make an unfounded claim, and then act as if I've just checkmated all of science."
I will reveal to your unseeing eyes the truth: there is no material universe

"because um...uh...this computer I am composing this comment on is solid, and we can perform objective, repeatable, experiments on it to confirm that it is made of material, and...uhhh...hold on. I need to do more DMT..."
Consciousness is all there is, period.

"BAM! I challenge your conclusion based on experimental evidence with a bare assertion. What, now, Socrates? What, now?"
All your experiments are being done on yourselves.

"Oh, and also, why is there science on this site, anyway? Isn't this realfairies.net? Whatever, man. I am sooooo stoned."
Tektrix
5 / 5 (2) Jan 27, 2016
"there is no material universe"

"Merrily, merrily, merrily, merrily, life is but a dream!" - Every Solipsist Since Gorgias
MrVibrating
not rated yet Jan 27, 2016
So how is solipsism different to total mental monism (or are they the same thing?) - anyone?
MrVibrating
5 / 5 (1) Jan 27, 2016
Maybe i'm just a figment of Bob Sage's imagination, and thefurlong and Tektrix are figments of mine? Which would mean i have rank..? Cool.

Regardless, i've long concluded that consciousness is a connective equilibrium, in an edge-of-chaos-criticality kind of way, and that octave equivalence is a hallmark of this ground state.

As an example of such a network, if we have a bunch of nodes (n) that we randomly connect two at a time, we find that a structural phase transition arises at 1/2n connections, as each connection has two ends and so connects two nodes. So if there's 90 nodes we need 45 connections, and so on. Adding more would be superfluous, but removing any would disconnect some nodes from the cluster.

It thus seems likely that there exists an intrinsic correlation between informational and thermodynamic entropies, and hence how we resolve and process information itself - ie. problem-solving via entropy reduction.

Or rather, how Bob Sage does. Obviously.
Sassen
5 / 5 (2) Jan 28, 2016
Consciousness is an emergent property of our brain indeed.
dougfgd
5 / 5 (1) Jan 28, 2016
Im guilty of not seeing where the problem is.
Consciousness is living with in the model of our own universe,,animals have evolved the model for survival as the better the model the better to ability to survive through anticipating events.
SkyLy
not rated yet Jan 31, 2016
Consciousness is an emergent property of our brain indeed.


Would then consciousness only be a function of the number of connexions ? This whole subjective experience ? I'd be surprised if it were.
FESTtheory
1 / 5 (1) Feb 02, 2016
BECOMING HUMAN / INTELLIGENCE : FINALLY SOLVED. NEW COMPREHENSIVE THEORY STARTS FROM THE END by establishing the working theory of functioning of the human brain-IQ, and assuming that the transfer of collective knowledge - from mother to incapable baby - is what created us, i.e. our (collective C+IQ) intelligence through multiple self-projection – MSP. The biggest picture (the framework) for all scientific data (Scientific Adam, Mitochondrial Eve, autism, speech, pleasure in the presence of fire, dreams...even A.I. because start, origin of original, in making AI is crucial / what has been missing) is FEST theory.
https://evolutionofhumanintelligence.wordpress.com/
SusejDog
5 / 5 (1) Feb 03, 2016
Just one word: DMT

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