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Monkey Mind I: Subjectivity and the Brain's Default Mode Network

So, what do you think about when you’re not thinking about anything else? Where does your mind go when it isn’t busy with goal-directed tasks requiring your attention, or being drawn to the external world by its normal busy set of events, its normal information overload? What is that part of your mind which just won’t shut up when you are trying to get to sleep, or that gets in the way when you are trying to quiet and center yourself in meditation, or even just “sit quietly in a room alone,” the inability from which Blaise Pascal asserted all of humanity’s problems stem?

This is what Buddhist meditators call “monkey mind,” that chattering ego which may be the root of all human suffering. It turns out that there is network in the brain that is suspended when you lose yourself in a task, originally called the “task negative network,” deactivated during most externally focused goal-directed tasks, which becomes activated within less than a second of finishing a task. This “resting state connectivity,” showing synchronicity in functional magnetic resonance imaging (fMRI), is correlated with the alternate deactivation of the areas of the brain involved in perception, language, and attention tasks. Most of us, when not doing much of anything else, tend to be yammering away, talking to ourselves, mostly about ourselves and our close personal relationships, past and future.

Marcus Raichle, working at the Washington University Med School, called this the “Default Mode Network,” active when you are not focused on the outside world, when your mind is wandering or daydreaming, but it is also active when you are (1) thinking about others, (2) thinking about yourself, (3) remembering the past, and (4) planning for the future. So what else do you think about when you aren’t thinking about anything else, or aren’t focused on some external task? Actually, even goal-oriented tasks that are autobiographical or use social working memory are correlated with activation of the Default Mode Network. This is a large scale network of interacting brain regions with activity highly correlated with each other, and negatively correlated with other networks, such as those involved in attention.

The brain does not cease to operate when one is at rest. Indeed, Raichle and others have shown that a focused mental task increases the brain's consumption of energy by less than 5%. Indeed, blood flow in the frontal cortex is highest when a person is at rest, and there is “intrinsic oscillatory behavior” in vertebrate neurons generally in Purkinje cells in the cerebellum, in the inferior olivary nucleus and in the thalamus. Think of this ”intrinsic oscillatory behavior” as a coordinating pattern of firing, like an audience applauding. It may be one of the mechanisms behind “long-distance” interactions between relatively distant parts of the brain. We’ll return later to what happens when some of this goes out of sequence.

Marcus Raichle and his group originally published “A default mode of brain function” in the Proceedings of the National Academy of Sciences in 2001. I was aware of work showing that areas of the brain active when we aren’t focused on anything else involved language areas and our interior dialogues, mainly about our close personal relationships. Indeed, I included some of this work in an upper-level undergraduate colloquium I taught on “Brain, Mind, and Spirit,” from 2001-2004, and on “Neuromythology: Brains and Stories,” from 2005-2009. Nevertheless, because of robust findings on the “independent component analysis” showing the long-distance effects in the default network, that effortless resting scans could be easily done on a wide range of populations, including clinical, developmental, and even nonhuman primates, research that only produced a dozen articles prior to 2007, produced over a thousand across the next seven years.

As a working scholar, my focus was elsewhere, teaching and publishing my initial synthesis of “Neuromythology” in Zygon: Journal of Religion and Science in 2006, and focusing on “relationality” for a conference in Madrid in 2008, and for the Institute on Religion in an Age of Science in 2009 (published in Zygon in 2011), and then on narrative and meaning, embodied and extended cognition, emotional psychology, and finally “Knowing Ourselves by Telling Stories to Ourselves” (Zygon 2017).

One of the nice things about retiring from academia in 2017 is the ability to step back, have some more perspective, and see that some other important things are going on. Indeed, it was the recommendation by two young alums of Michael Pollan’s wonderful book How to Change Your Mind, that not only alerted me to the neuroscience of the default brain network, but to the renewal of several generations of long-lost research on psychedelic drugs, with extensive research projects going on at Johns-Hopkins, UCLA, and New York University. A major Swiss conference in 2006 included the nonagenarian Albert Hoffman, who first synthesized LSD in 1943, ten years before Aldous Huxley’s Doors of Perception

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