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Here’s a wonderful article from Time Healthland Ezine revealing how the brain loses consciousness. It looks like the brain functions as a whole or a cluster of relationships and that consciousness is a product of the whole rather than residing in one place like a seat of consciousness – which sits nicely in a holistic model of consciousness being an outcome of cell communication. Read on…
“What happens to your brain as it slips into unconsciousness? A new technique allows researchers to view real-time 3-D images of a patient undergoing anesthesia using the drug propofol, and the findings show that consciousness isn’t suddenly switched off, but rather fades as though a dimmer is being dialed down.
The research also suggests that consciousness resides in the connections between multiple parts of the brain, not in any single region. The images show that changes in the anesthetized brain start in the midbrain, where certain receptors for a neurotransmitter called GABA are plentiful.
Below are some interesting quotes on CSF flow from recent research using new computer modelling of CSF flow in the third ventricle from MRI scans. There are also some great images on the site of Dr Vartan Kurtcuoglu. (Many thanks to GP Visser, dentist and current student on the current CTET training, for pointing out the papers.)
‘Unlike the cardiac system, there is no dedicated pump, such as the heart, that directly drives the CSF flow. The CSF is propelled in a pulsatile manner, primarily due to brain motion caused by the expansion and contraction of cerebral blood vessels. Superimposed on this motion is flow generated by the secretion of CSF by the choroid plexus in the ventricles at the center of the brain and cerebrospinal fluid absorption, predominantly at the arachnoid villi in the subarachnoid space that surrounds the brain (Davson and Segal, 1996). Additional drainage into the blood-stream is purported to occur through the cerebral extracellular space (Greitz, 1993).’ (Kurtcuoglu et al 2007)
‘The CSF further serves as an intermediary between blood and nervous tissue, providing the latter with nutrients and removing waste products. Recent research shows that the cerebrospinal fluid flow is much more important than previously believed. For example, the pituitary gland and hypothalamus communicate through the CSF and new neurons follow the flow of cerebrospinal fluid in the adult brain.’ (Kurtcuoglu 2011)
Sources of information into the deep brain centres that control our primitive reflexes to being overwhelmed
We can frame three essential principles on how the nervous system works that are relevant to cranial work:
Take a trip to the Prairies of Northern America and you will notice a remarkable phenomenon that has gone un-named for a long time, the effect of the horizon on our consciousness. People living on Prairies are different than people living in valleys or hills. The constant presence of the flat country creates a huge orientation to the big blue sky. That’s why they call it Big Sky Country and that means you are able to take in an extended horizon as the sky meets the earth. There’s something primeval about the meeting place between these two constants in our lives that starts a powerful physiological response. Just thinking about the horizon meets with a big response in the body. Try it, stare at the image below and see what happens in your body and mind. Then try imagining the horizon and follow the responses. It’s as if the horizon reminds us of greater universal forces and a more connected scale of nature, after all the horizon represents the curve of the Earth as a planet and therefore its relationship to other planetary bodies and the cosmos. The sky doesn’t do this on its own, it gives a sense of space and room and the Earth gives a sense of the details of life but the horizon shows us our planet and takes us into a connection with a larger world.
In the book we explore the ideas that socialisation and dealing with gravity were some of the selective pressures that helped trigger an increase in the size of the brain. It is a useful question if we add the ideas that ‘junk in equals junk out’ and a big brain is essential to becoming conscious. The brain is an information processing device that needs good input to function. So understanding that certain inputs were critical to the development of the brain, both in evolution and in growing up, helps us choose pathways to stimulate those inputs to improve the functioning of the brain in the adult.
http://www.guardian.co.uk/technology/2010/mar/28/colin-blakemore-how-human-brains-got-bigger
The above article dismisses the idea that there was gradual development in the brain due to selective pressures. The argument that stimulating pathways that deal with gravity and socialisation helps improve the brain function in the adult does not necessarily need an evolutionary basis for it to be valid, but I have always liked it as an explanation. If Blakemore is correct I will have to let go of that. Hey ho.
The science around mirror neurons is very exciting. It appears perception involves a mimicking of what is around us within our internal environment. If we see a beautiful dancer dancing, our brain is reproducing what we are seeing in the brain’s motor areas, causing physiological responses within our own bodies. Our bodies model and feel the dancer’s movements. Here is V.S Ramachandran from a recent ted.com talk:
‘But a subset of them will fire even when I watch somebody else being touched in the same location. So, here again you have neurons which are enrolled in empathy. Now, the question then arises: If I simply watch another person being touched, why do I not get confused and literally feel that touch sensation merely by watching somebody being touched? I mean, I empathize with that person but I don’t literally feel the touch. Well, that’s because you’ve got receptors in your skin, touch and pain receptors, going back into your brain and saying don’t worry, you’re not being touched. So, empathize, by all means, with the other person. but do not actually experience the touch otherwise you’ll get confused and muddled.
Okay, so there is a feedback signal that vetos the signal of the mirror neuron preventing you from consciously experiencing that touch. But if you remove the arm, you simply anesthetize my arm, so you put an injection into my arm, anesthetize the brachial plexus, so the arm is numb, and there is no sensations coming in, if I now watch you being touched, I literally feel it in my hand. In other words, you have dissolved the barrier between you and other human beings. So, I call them Gandhi neurons, or empathy neurons.
And this is not in some abstract metaphorical sense, all that’s separating you from him, from the other person, is your skin. Remove the skin, you experience that person’s touch in your mind. You’ve dissolved the barrier between you and other human beings. And this, of course is the basis of much of Eastern philosophy, And that is there is no real independent self, aloof from other human beings, inspecting the world, inspecting other people. You are in fact, connected not just via Facebook, and Internet, you’re actually quite literally connected by your neurons. And there is whole chains of neurons around this room, talking to each other. And there is no real distinctiveness of your consciousness from somebody else’s consciousness.’
Click here for the TED.com talk by V.S Ramachandran
Mirror neurons help us understand that perception is an embodied, visceral experience. By learning to be more aware of our own responses we can become more sensitive to what is happening in other peoples bodies. Mirror neurons show us that we have the ability to internally model what they are doing.
Steve Haines
Ged Sumner
