Episode 140: This is Your Brain on Meditation
This week we speak with academic nuerologist and Zen practitioner James Austin. Austin, who wrote the well-known book, Zen and the Brain,
joins us to explain some of the physical mechanisms underlying both
attention and the way we process reality. In terms of attention, he
shares with us a very descriptive difference between "top-down" and
"bottom-up" modes of attention. He also shares the difference, from
the perspective of the brain, between self-centered (egocentric)
processing and other-centered (allocentric) processing.
He also shares the ways in which these two are related to the different forms of meditation that are commonly seen in the Buddhist tradition. Although sometimes technical, his descriptions are extremely interesting for those who have an interest on the intersection between meditation and the brain.
This is part 1 of a two-part series. Listen to part 2, The Mechanisms of Kensho.
Vince: Hello Buddhist Geeks. This is Vince Horn and I'm here today joined over the phone by James Austin. James, thanks so much for taking the time to speak with me. It’s really appreciated.
James: My pleasure.
Vince: And just a little bit of your background, so people know your areas of expertise and specialty. You are a trained academic neurologist and researcher and also a long time Zen practitioner and it's the intersection of those two fields which is really been one of your primary interests and you have written several book on the topic of Zen and the brain, and your most recent one is called Selfless Insight, which will hopefully get into. But first, I thought it'd be a good idea to give people a sense of what your background with the Zen tradition is, because you've been practicing for several decades and I thought it'd be cool if we could just hear about how you were first exposed to Zen and as I understand it was while you were in Japan, in Kyoto
James: Right. I came about by accident. I'd gone to Kyoto in 1974, to do a bench research on the brain and I happened, as luck would have it, to be near, and was referred to an English speaking Zen Master Kobori Roshi. Kobori Roshi introduced me to Rinzai Zen and it was this really that captured my imagination, particularly after a few weeks, when during the moments of absorption, in the evening, I dropped into an alternate state of consciousness, in which my physical sense of self dropped down of the center of my awareness and I also entered a state in which there was no sound, a state in which the vision was blacker than black, and a state which was later permeated by a sense of a bliss. For a neurologist, to drop into a state where vision dropped out and hearing dropped out, this was quite an eye opener for me, and led me to believe that there was really something to this Zen meditation and so this continued to enlist my interest in subsequent decades and really strengthened my resolve to continue practice and also my interest in finding out what actually was going on in the brain when one meditates and when one entered these alternative states of consciousness.
Vince: Right. And that is one of the main topics we waned to explore with you because is such an interesting one and maybe we can kick it off by discussing or exploring some of the main distinctions you make in your writing work. And the first one I thought would be interesting to take a look at is a difference between what you're calling top-down and bottom-up modes of attention. I was wondering if you could say something about that distinction.
James: Yes. These two words top-down and bottom-up have entered into our understanding of attention pretty much in this last decade and let's start with top-down attention cause that's the way we usually begin to meditate.
We usually, literally, look down, usually at some spot that's on the floor in front of us or the wall and we engage in a concentration that is more voluntary, it's intentional. It's executive and it's more or less exclusive in the sense that we are excluding everything outside that small focus of our original attention. It turns out that when this particular style of attention is studied in normal people, it's found to engage mostly the regions in the upper more dorsal part of the brain.
And there are two particular areas called modules that are involved in this top-down attention. The first is an important one, in the parietal lobe, and the second area that's involved in top-down attention is another area in front of that, in the frontal lobe in the region of the frontal eye field, the area that helps us gaze to certain parts of our environment. So these two modules, one parietal, one frontal in the dorsal part of the brain have been identified, particularly by the group at Washington University at St. Louis, Corbetta and Shulman, and these areas respond to cues that the investigators have presented to their subjects that tell the subject what they might be experiencing in a few seconds, where the stimulus might be coming from, and even when the stimulus might be occurring. So this is kind of an intentional, focused, intelligent way that's voluntary to responding, it turns out, to the opposite side of the environment. So, in these words I've been trying to put together what the dorsal attention system does when it engages in what we call top-down attention.
Now, the second kind of attention that we pay, normally, to our environment… actually, it’s a misnomer to use the word "pay" because this is a kind of subtler attention that is reflexive. It’s automatic. When it attends it's on the lookout for things that might happen unexpectedly. Researchers don't warn their subjects about stimuli that might be coming in. The subjects pretty much have to pick up these stimuli automatically by staying aware and by staying alert. This has also been called a kind of choiceless awareness, in the sense that the subject is not choosing to pay attention to one focal region, but stays attentive to whatever might happen out in the external environment. And that's called bottom-up attention.
It turns out that actually the parts of the brain that are responsible for this kind of attentive processing are located at a lower, more ventral level, than the dorsal attention system. The particular areas are mostly in the temporal parietal junction on the right side. And the other right-sided region is in the ventro-lateral frontal cortex, again on the right side. So, what do these mostly right-sided regions do? It turns out that they pay this involuntary, reflexive attention to both the right and left sides of the environment. Now, if you've sort of been prepared to accept that your left sided temporal and frontal regions are most concerned with your language operations, with words and your expressive speech, and your receptive speech, it becomes a little easier to understand that the brain delegated to the right side of the brain this important function of paying attention to both sides of the environment.
So to summarize then, we’ve got two different modes of paying attention. One sort of looks down and is mostly in the upper part of the brain. When it looks down it pays attention mostly things that are in front of it. It pays attention to things that we can grasp close to are body like tools, and in doing that by the way, in grasping things close to our body with our hands and fingers using tools we're mostly relying on our senses of touch in our fingers and proprioception in our fingers. These are clearly parietal lobe oriented functions, so I hope you're getting the sense that were talking more about a top-down function that is more in the parietal lobe.
On the other hand the central attention system, because it's mostly coursing through lower parts of the brain, particularly in the lower temporal and lower frontal lobe that's relying more on our senses of vision and sense of hearing, and these senses are designed to help us detect and identify things that are out of reach of our finger, things at a distance, things way off in the distance. In fact and instead of looking down in order to identify these its efficiencies are designed more in the direction of identifying and seeing and hearing things in the at a distance from us often by looking up or by listening up. So there you are, two forms of attention involving very different parts of the brain and the importance of these for meditators I think with a little reflection you can start beginning to imagine because basically our two different kinds of attentive arts we engage in when we meditate fall into similar categories
James: Our concentrative meditation is more effortful. It’s more sustained, focused, and exclusive it requires top-down attentive processing. It’s more self-referential. It may evolve into the absorption of the jhānas, and it can be kind of summarized as paying attention. Whereas the more receptive modes of meditation are more unfocused. They’re more effortless. They’re more open. They involve only a bare awareness that expresses bottom-up modes of processing there more involuntary there other referential there tuned to the world outside and they're the ones who can shift into our more intuitive and insightful modes of awareness and they're clearly choiceless because we're not in there choosing to do with them, they more or less take place automatically. So it's these two major modes of attention that overlap in significant ways with comparable styles of meditation the one is concentrated and the other is receptive.
Vince: And this really closely connects to what you call egocentric and allocentric. The certain senses are kind of focused on the self, and then other senses…
Vince: …are kind of refocused on the outside, and that seems to bring up this interesting question about duality in the brain.
James: Well, it turns out that the brain really has two ways of perceiving reality. Reality is something, in one sense, that clearly refers back to us as an experiencer, back in the center. That’s one way, that’s called egocentric processing. But there’s another way of processing reality, which is not egocentric. Ego, has as its opposing word, Allo. Allo means “other”. Ego means “self” centered.
Other-centered processing refers to the way we identify things in the outside world, out there, more or less leading them out there where they exist in co-relationships with other objects that are “out there”, away from us. Clearly, our egocentric way of processing things is inherently more subjective, because we’re “in there.” We’re the subject. There is an inherently more objective, that is non-personal, impersonal way of perceiving objects, and that is accomplished by the allocentric processing stream.
Now, here again, the egocentric processing stream, having started visually in the occipital lobe, has its trajectory that moves upward and toward the parietal lobe in the dorsal part of the brain. In contrast, the allocentric processing stream, having also started occipitally, has its trajectory downward moving, toward the inferior temporal region, and then on into the interior frontal lobe. The egocentric processing stream is clearly oriented to serve our own abilities to act in the environment. The allocentric processing stream is much more relative. It can be highly abstract. It depends on vision and hearing. It taps into the stream that asks, “What is it, out there in the outside environment?” In contrast, the egocentric processing stream is designed to say, “Where is it?” and to answer that question, and then to proceed to answer how one should act as a person.
So we’ve got these three general topics. The first is attention. The second relates to meditation, the ways we meditate. The third relates to the question you asked about how do we process reality in two different ways, and there are very important “overlappings” between these three topics. The overlappings show that they are as complimentary as yin and yang. They’re opposite functions, and yet they’re balanced and they operate in a neat, balanced way to help us function both as meditators and as people who are interpreting and acting in the real world.