Cool article from Talking Philosophy. Philosophy and neuroscience are beginning to take seriously some Buddhist meditation practices - finally. So here Mason asks if we can think of nothing and stay awake. If only it were that simple - thinking of nothing is very hard, an advanced practice for many people.
On the other hand, Mason does not actually get to clear mind awareness - and there is a reason why this is more challenging than one might wish - see below.
It turns out that the brain uses a LOT of energy to push things out of awareness (hmmm . . . I can see it now, a new weight loss strategy based on repression). This article from last fall looks at the metabolic cost of NOT thinking about something.Thinking of Nothing
By Jeff Mason ⋅ January 17, 2011Is it possible to think of nothing and remain awake? Is thinking of nothing the same as not thinking at all? Is being conscious of something the same as thinking? Do all thoughts take objects? Where do ‘objects of thought’ come from? Perhaps these are odd questions. Usually there is no need to ask. Thinking is about something or other.
We spend a lot of time thinking about the future. This includes all the mundane things we have to plan for and carry out. It includes thinking about what is coming up for our health, education and job prospects, relationships, the state of the economy, politics, retirement, taxes, death; in short, all the things that people care about that point to the future.
We spend most of the rest of the time thinking about the past. I think of the good times and the bad times, the people I have known. Sometimes an old landscape comes before my imagination, now covered with houses and roads, sometimes a flower I have seen, or the smell of orange blossoms in spring. I think of old loves and passions, the turmoil of youth, the work of middle age, and the reflections of later life. Looking back, we can try to see the meaning hidden in events that were too close and involving to be understood clearly at the time.
Can objects of thought come from the present? I do not see why not. Bringing your attention to sensations or perceptions of objects brings you directly to the present. This is because the living body is rooted in the present in a way that thinking is not. For example, to become conscious of the feeling in your left foot is to come into the present of your body at a particular moment. Similarly, becoming aware of the specific perceptual qualities of an object also brings you to your senses. So if you were to see a rare bird and remember to pay attention to its color, and the flash of its wings, this, too, brings you into the present of your body as perceptual system. All too often one is ‘elsewhere’ when the bird passes by. In addition, there are contemplative practices that fill the present meaning, as in Plato’s intellectual contemplation of the Forms or religious contemplation of sacred symbols. However, such objects are not temporal in the same way as sensations or objects of perception.
Yet more objects of thought come from subjects like logic, mathematics and geometry. The objects of these studies are universal necessary truths that do not depend upon contingent facts for their validation. I can intuit some simple truths like this. For example, I can see a circle is round and a square is rectangular. So, if I take up a position, as Spinoza suggested, “under the aspect of eternity”, I am thinking about something that does not change over time. Every time I look at a circle, I can be sure to see its circular shape. Some objects of thought are timeless.
Have I left anything out? What about “Mindfulness?” Does mindfulness count as thinking about something or nothing? By “mindfulness” I am thinking of a dedicated or “single-minded” mindfulness. Roughly speaking, this form of mindfulness brings one into the present moment without comment or judgment. One is simply in watchfulness over what transpires within one’s field of bodily/mental experience. Mindfulness is word free, a simple awareness of a present actuality that cannot be named, but can be encountered in stillness. Chattering to oneself destroys it. The words that make up our descriptions and explanations distract us from the moment.
One can be mindful in different ways. I am mindful of the pavement so that I do not trip, or mindful of the feelings of others. I am mindful of putting the silverware away, conscious of putting each fork or knife into it proper place. Here, we are still thinking of things, albeit in a mindful way that brings us more fully into the present moment. Nevertheless, discursive or calculative thinking is incompatible with ’single-minded’ mindfulness.
So, can one think of nothing and remain awake? The answer is ‘yes’ in the case of ’single-minded’ mindfulness. It is thinking of nothing in the sense of not categorizing things or making calculations about them. It is neither having abstract truths before one’s imagination, contemplating symbols or images, nor attending to sensations. ‘Single-minded’ mindfulness is neither engaged in the world, nor apart from it. It does not tell itself stories, valuing or negating, wishing or hoping, but receives and accepts whatever is going on as long as it continues; allowing thoughts and feelings, words and images, to exist as soon as they arise and to let them go as soon as they are ready to leave.
Reference:Why Thinking of Nothing Can Be So Tiring: Brain Wolfs Energy to Stop Thinking
ScienceDaily (Sep. 21, 2010) — Ever wonder why it's such an effort to forget about work while on vacation or to silence that annoying song that's playing over and over in your head?
Mathematicians at Case Western Reserve University may have part of the answer.
They've found that just as thinking burns energy, stopping a thought burns energy -- like stopping a truck on a downhill slope.
"Maybe this explains why it is so tiring to relax and think about nothing," said Daniela Calvetti, professor of mathematics, and one of the authors of a new brain study. Their work is published in an advanced online publication of Journal of Cerebral Blood Flow & Metabolism.
Opening up the brain for detailed monitoring isn't practical. So, to understand energy usage, Calvetti teamed with Erkki Somersalo, professor of mathematics, and Rossana Occhipinti, who used this work to help earn a PhD in math last year and is now a postdoctoral researcher in the department of physiology and biophysics at the Case Western Reserve School of Medicine. They developed equations and statistics and built a computer model of brain metabolism.
The computer simulations for this study were obtained by using Metabolica, a software package that Calvetti and Somersalo have designed to study complex metabolic systems. The software produces a numeric rendering of the pathways linking excitatory neurons that transmit thought or inhibitory neurons that put on the brakes with star-like brain cells called astrocytes. Astrocytes cater essential chemicals and functions to both kinds of neurons.
To stop a thought, the brain uses inhibitory neurons to prevent excitatory neurons from passing information from one to another.
"The inhibitory neurons are like a priest saying, 'Don't do it,'" Calvetti said. The "priest neurons" block information by releasing gamma aminobutyric acid, commonly called GABA, which counteracts the effect of the neurotransmitter glutamate by excitatory neurons.
Glutamate opens the synaptic gates. GABA holds the gates closed.
"The astrocytes, which are the Cinderellas of the brain, consume large amounts of oxygen mopping up and recycling the GABA and the glutamate, which is a neurotoxin," Somersalo said.
More oxygen requires more blood flow, although the connection between cerebral metabolism and hemodynamics is not fully understood yet.
All together, "It's a surprising expense to keep inhibition on," he said.
The group plans to more closely compare energy use of excitatory and inhibitory neurons by running simultaneous simulations of both processes.
The researchers are plumbing basic science but their goal is to help solve human problems.
Brain disease or damaging conditions are often difficult to diagnose until advanced stages. Most brain maladies, however, are linked to energy metabolism and understanding what is the norm may enable doctors to detect problems earlier.
The toll inhibition takes may, in particular, be relevant to neurodegenerative diseases. "And that is truly exciting" Calvetti said.
Rossana Occhipinti, Erkki Somersalo, Daniela Calvetti. Energetics of inhibition: insights with a computational model of the human GABAergic neuron–astrocyte cellular complex. Journal of Cerebral Blood Flow & Metabolism, 2010; DOI: 10.1038/jcbfm.2010.107
No comments:
Post a Comment