禅定中佛教僧侣的脑部扫描研究
Brains of Buddhist monks scanned in meditation study
BBC新闻
BBC News
作者:马特·丹兹克
By Matt Danzico
智悲翻译中心/才让桑珠 译
卓然·约西波维奇在帮助一位佛教僧人进入磁共振成像仪。约西波维奇在他的研究中已经对20位有经验的禅修者进行了脑部活动扫描。
观测僧侣大脑的研究
美国纽约——在远离纽约街头喧嚣的一间实验室里,一位柔声细语的神经学家在将一位藏传佛教僧人安置在一部轿车大小的脑部扫描仪内以便更好地了解古老的禅定修行。
约西波维奇在他的研究中,已经对20多位深富经验的禅修者进行了脑部扫描。
这种不寻常的研究不仅能够揭示和谐人生的秘密,也能昭示世界上更多的神秘疾病,是这样吗?
卓然·约西波维奇是一位研究科学家和纽约大学副教授,他说他一直从事观测禅定中僧侣的大脑活动,旨在理解在打坐过程中他们的大脑是如何重组的。
从2008年起,他就开始用一台5吨(5000公斤)的功能性磁共振成像仪对杰出的佛教人物进行心智和身体上的研究。
这台扫描仪可以跟踪在其笨重墙壁内禅定的僧人头部内的血流,机器运行时会发出有韵律的声音。
作为一名佛教徒,约西波维奇博士也兼职,他说他希望能够发现某些禅修者如何能够达到“无二元对立”或者是与世界“合一”的状态,即一个人与他们外部环境融合的意识形态。
卓然·约西波维奇正在看脑部电脑扫描结果。他的研究特别关注大脑的默认神经网络,这个网络控制着自我反省的思想。
约西波维奇博士说:“对那些用大量时间打坐的人来说禅定所做的一件事情是培养注意力的技巧”,并且通过这些娴熟的技巧能使他们达到一个更宁静和更快乐的存在方式。
“特别是过去的10年或更长的时间里,关于禅定的研究已显示出此项研究非常有前途,因为它指出了大脑可能有某种能力,这种能力以某种以前我们并不知道的方式改变和优化我们的大脑。”
具体地观察大脑默认神经网络的研究,这个网络控制自我反省的思想。
约西波维奇说:“当一个人放松并进入合一的状态时,富有经验的修行人,他的神经网络就会改变,因为他们打破了他们自己与外部环境之间的心理隔阂。”
并且大脑的这种重组可以导致某些禅修者所说的一种人与自然的深度和谐。
转移注意力
约西波维奇博士的研究是更好地了解目前科学家称为大脑默认神经网络的大量研究的一部分。他说大脑似乎被组织成两个网络:外部神经网络和内部、或称为默认神经网络。
当一个人正在专注外部活动时,如做运动或倒一杯咖啡,他大脑的外部神经网络会活跃起来。
当人们反省涉及自己和自己情绪的事情时,默认神经网络会改变。
但两个神经网络很少在同一时间内全部活跃,就像一个跷跷板,一头起来的时候另一头会下去。
这种神经网络的设定使个体在任意时间都能更容易地专注一件事情,而没有被诸如白日梦这样的干扰所分心。
约西波维奇博士说:“从基本上来说,我们正努力做的事情就是,当人的注意力在这两种模式之间转移时,去跟踪大脑神经网络的变化。”
约西波维奇博士发现某些佛教僧侣和其它有经验的禅修者在禅定期间有能力保持两个神经网络在同一时间都活跃——也就是说,他们发现了让跷跷板两头都翘起来的方法。
约西波维奇博士认为这种大脑内部和外部神经网络同时活跃的能力会使禅修者体验到人与自然合一的和谐感觉。
自我反思
以前科学家认为自我反省,大脑的默认网络是简单的,因为当一个人没有要关注的目标时它才活跃。
但是在过去十几年的研究中,科学家发现大脑的这部分神经网络,当主体在考虑自己时它随着活动而膨胀。
2001年当美国密苏里州华盛顿大学医学院的神经学家马库斯·雷克尔博士开始对那些没有给予执行任务的个体进行脑部扫描时,才出现了默认神经网络的这种研究亮点。
患者会很快就厌倦了,然而,雷克尔博士注意到一个第二种的网络,即一个以前没有注意到的网络开始活动起来。但研究人员不清楚为何会出现这种活动。
其它科学家很快向雷克尔博士建议这种情况可能是博士的受试者实际上在考虑他们自己。
很快那些正在从事电影对脑部刺激研究的其他神经科学家,发现每当电影间歇时默认神经网络开始活跃,这可能是研究的受试者因为无聊开始了自我反思。
但是雷克尔博士说默认神经网络的重要性,远远不止仅仅是在思考昨天晚上吃了什么晚饭。
雷克尔博士说:“研究者开始考虑我们如何知道我们究竟是谁。默认模式的神经网络可以解释关于事物如何以他们所存在的方式出现(自然本性)”。
并且雷克尔博士指出默认神经网络的研究将有助于揭开某些心理紊乱的秘密,如忧郁症,自闭症,甚至是老年痴呆病。
“如果你研究老年痴呆病,你就要研究它是否会对大脑那个特殊部位带来伤害,使人惊诧的是它确实影响了默认神经网络。”像约西波维奇博士一样,雷克尔博士也认为关于固有的神经网络的研究能有助于解释这个问题。
辛迪·勒斯蒂格,密歇根大学心理学和神经科学副教授,也同意这个观点。
她说:“默认神经网络是大脑主要的和替代的网络,似乎目前的研究都是涉及大量的神经障碍疾病,如自闭症,老年痴呆症等,而了解它与面向任务的网络之间如何互动至关重要。它是其他已被忽略了太久的难题中的一种。”
为了更好地了解这个神秘的神经网络,约西波维奇博士已经对20多位禅修者做过脑部扫描,这些受试者包括比丘和比丘尼,他们主要是按藏传佛教的传承进行禅修。
他说他的研究成果很快就会发表,尽管沿着这个思路了解自闭症和老年痴呆症的进展会带来一定可观的奖励,但他将继续关注于解释天人合一境界或入定的神经学的含义。
In a laboratory tucked away off a noisy New York City street, a soft-spoken neuroscientist has been placing Tibetan Buddhist monks into a car-sized brain scanner to better understand the ancient practice of meditation. But could this unusual research not only unravel the secrets of leading a harmonious life but also shed light on some of the world’s more mysterious diseases? Zoran Josipovic, a research scientist and adjunct professor at New York University, says he has been peering into the brains of monks while they meditate in an attempt to understand how their brains reorganise themselves during the exercise.
Since 2008, the researcher has been placing the minds and bodies of prominent Buddhist figures into a five-tonne (5,000kg) functional magnetic resonance imaging (fMRI) machine. The scanner tracks blood flow within the monks’ heads as they meditate inside its clunky walls, which echoes a musical rhythm when the machine is operating. Dr Josipovic, who also moonlights as a Buddhist monk, says he is hoping to find how some meditators achieve a state of nonduality or oneness with the world, a unifying consciousness between a person and their environment. One thing that meditation does for those who practise it a lot is that it cultivates attentional skills, Dr Josipovic says, adding that those harnessed skills can help lead to a more tranquil and happier way of being. Meditation research, particularly in the last 10 years or so, has shown to be very promising because it points to an ability of the brain to change and optimise in a way we didn’t know previously was possible. When one relaxes into a state of oneness, the neural networks in experienced practitioners change as they lower the psychological wall between themselves and their environments, Dr Josipovic says. And this reorganisation in the brain may lead to what some meditators claim to be a deep harmony between themselves and their surroundings. Shifting attention
Dr Josipovic’s research is part of a larger effort better to understand what scientists have dubbed the default network in the brain. He says the brain appears to be organised into two networks: the extrinsic network and the intrinsic, or default, network. The extrinsic portion of the brain becomes active when individuals are focused on external tasks, like playing sports or pouring a cup of coffee. The default network churns when people reflect on matters that involve themselves and their emotions. But the networks are rarely fully active at the same time. And like a seesaw, when one rises, the other one dips down. This neural set-up allows individuals to concentrate more easily on one task at any given time, without being consumed by distractions like daydreaming. What we’re trying to do is basically track the changes in the networks in the brain as the person shifts between these modes of attention, Dr Josipovic says. Dr Josipovic has found that some Buddhist monks and other experienced meditators have the ability to keep both neural networks active at the same time during meditation - that is to say, they have found a way to lift both sides of the seesaw simultaneously. And Dr Josipovic believes this ability to churn both the internal and external networks in the brain concurrently may lead the monks to experience a harmonious feeling of oneness with their environment. Self-reflection
Scientists previously believed the self-reflective, default network in the brain was simply one that was active when a person had no task on which to focus their attention. But researchers have found in the past decade that this section of the brain swells with activity when the subject thinks about the self. The default network came to light in 2001 when Dr Marcus Raichle, a neurologist at the Washington University School of Medicine in the US state of Missouri, began scanning the brains of individuals who were not given tasks to perform. The patients quickly became bored, and Dr Raichle noticed a second network, that had previously gone unnoticed, danced with activity. But the researcher was unclear why this activity was occurring. Other scientists were quick to suggest that Dr Raichle’s subjects could have actually been thinking about themselves. Soon other neuroscientists, who conducted studies using movies to stimulate the brain, found that when there was a lull of activity in a film, the default network began to flash - signalling that research subjects may have begun to think about themselves out of boredom. But Dr Raichle says the default network is important for more than just thinking about what one had for dinner last night. Researchers have wrestled with this idea of how we know we are who we are. The default mode network says something about how that might have come to be, he says. And Dr Raichle adds that those studying the default network may also help in uncovering the secrets surrounding some psychological disorders, like depression, autism and even Alzheimer’s disease. If you look at Alzheimer’s Disease, and you look at whether it attacks a particular part of the brain, what’s amazing is that it actually attacks the default mode network, says Dr Raichle, adding that intrinsic network research, like Dr Josipovic’s, could assist in explaining why that is. Cindy Lustig, associate professor of psychology and neuroscience at the University of Michigan, agrees. It’s a major and understudied network in the brain that seems to be very involved in a lot of neurological disorders, including autism and Alzheimer’s, and understanding how that network interacts with the task-oriented [extrinsic] network is important, she says. It is sort of the other piece of the puzzle that’s been ignored for too long. Dr Josipovic has scanned the brains of more than 20 experienced meditators, both monks and nuns who primarily study the Tibetan Buddhist style of meditation, to better understand this mysterious network. He says his research, which will soon be published, will for the moment continue to concentrate on explaining the neurological implications of oneness and tranquillity - though improving understanding of autism or Alzheimer’s along the way would certainly be quite a bonus.