The human brain's infinite dimensions

by Danai Chanchaochai, Bangkok Post, Dec 1, 2004

Bangkok, Thailand -- There are two quotes about the brain that I like. One is the well-known remark by Robert Frost, "The brain is a wonderful organ. It starts working the moment you get up and does not stop until you get into the office." The other is by an unknown author who no doubt was inspired by the original. "The human brain is a wonderful organ. It starts working the moment we are born and stops only when we are about to make our first public speech." I suppose this kind of plagiarism is excusable because it rings true. It's also mildly amusing.

Woody Allen has famously said that his brain is his second favourite organ. What he did not say is that without a functioning brain he would not be able to enjoy the capabilities of his first favourite. The human brain is indeed a wonderful organ and its amazing capabilities are still being explored with yet more new discoveries confounding long held scientific ideas.

The brain is an organ that is designed to change in response to experience. Neuroscience and psychological research over the past decade on this topic has burgeoned and is leading to new insights about the many ways in which the brain changes in response to experience. This basic issue is being studied at many different levels, in different species, and on different time scales. Yet all of the work invariably leads to the conclusion that the brain is not static but rather is dynamically changing and undergoes such changes throughout its entire life.

This flexibility of the brain, which allows it to adapt to the ever changing variety of challenges that we constantly throw at it, is referred to by the cognitive neuroscientists as neuroplasticity, a neat and concise explanation that should require no further explanation, but which in fact describes highly complex processes that change constantly. Those neuroscientists will tell us, by the way, that this synaptic plasticity forms the basis for adaptation within the brains neural networks.

Synaptic plasticity neural networks, are, of course, wonderful conversation stoppers. It's all a question of synaptic plasticity of course, and how this makes possible the amazing adaptation that takes places within the neural networks.

In other words, the brain is indeed a wonderful organ which works continuously throughout our life. It is also highly adaptable and changes all the time.

What do we mean when we say it changes all the time?

According to most neuroscientists, it means that the brain is constantly changing in its physical form and the way it organises itself. Those same scientists have made many discoveries recently about how the brain works and how it develops. They point out that at birth, the brain is very immature. In fact, the human brain is not fully mature until at least twenty years after birth. Moreover, during this long development the human brain is highly dependent on and is modified and shaped by experience. For example, in people born blind the parts of the brain that normally process visual information are rewired and come to process sounds, including language. In those born deaf, the areas of the brain that normally process sounds come to process vision. In this sense, those individuals see with their ears.

The language relevant brain systems are also shaped by experience. In people who learn a language later than six years of age, the brain systems that normally process grammar are not used. However, the brain systems that process the meanings of words are normal in late language learners. Children whose parents or teachers talk to them regularly display good language skills and well organised language brain systems. However children who are rarely spoken to have stunted language development and immature language brain systems.

Typical human and animal environments are complex and research has shown that such stimulating environments lead to enhanced brain growth, learning and intelligence. Furthermore, studies of animals and humans have shown that nurturing caregivers and low levels of stress are important in producing appropriate levels of the brain chemicals that are necessary for healthy emotional control. High levels of stress and the absence of nurturing caregivers result in high levels of the chemicals that are harmful to these systems.

In summary, contrary to what many people used to think, the human brain is a constantly changing, highly dynamic organ.

All this talk of neuroplasticity may seem a little too technical for some of us but it's a fair bet that many of us familiar with Vipassana meditation will already be saying to ourselves that we may not be familiar with the scientific terminology but that we have along understood that our brain is much more than neural pathways and complicated circuitry. And we are well aware of its ever changing nature.

This perhaps inevitable link between Buddhist meditation has recently become even more meaningful, highlighted by a report of the 12th Conference on Mind and Life, an ongoing dialogue between scientists and Buddhist scholars. The topic of this latest conference in the presence of the Dalai Lama was none other than neuroplasticity or more fully, "Neuroplasticity: The Neuronal Substrates of Learning and Transformation".

The Dalai Lama has long been encouraging Buddhist practitioners to blend their spiritual knowledge with modern scientific knowledge. The Mind and Life Institute says, "Along with his vigorous interest in learning about the newest developments in science, His Holiness brings to bear both a voice for the humanistic implications of the findings, and a high degree of intuitive methodological sophistication. As well as engaging personally in dialogue with Western scientists and promoting scientific research into Buddhist meditative practices, he has led a campaign to introduce basic science education in Tibetan Buddhist monastic colleges and academic centers, and has encouraged Tibetan scholars to engage with science as a way of revitalising the Tibetan philosophical tradition. His Holiness believes that science and Buddhism share a common objective: to serve humanity and create a better understanding of the world. He feels that science offers powerful tools for understanding the interconnectedness of all life, and that such understanding provides an essential rationale for ethical behavior and the protection of the environment."

At the conference with the encouragement of the Dalai Lama, neuroscientist Richard Davidson of the University of Wisconsin, scanned the brains of Buddhist monks.

The brain activity in volunteers who were novice meditators was compared with that of Buddhist monks who had spent more than 10,000 hours in meditation. The task was to practice "compassion" meditation, generating a feeling of loving kindness toward all beings. "We tried to generate a mental state in which compassion permeates the whole mind with no other thoughts," says Matthieu Ricard, a Buddhist monk at Shechen Monastery in Kathmandu, Nepal.

In yet another scientific confirmation of the power of meditation, the results of the scans of the monks showed dramatic increase in high-frequency brain activity called gamma waves during compassion meditation. Gamma waves underlie higher mental activity such as consciousness. The novice meditators "showed a slight increase in gamma activity, but most monks showed extremely large increases of a sort that has never been reported before in the neuroscience literature," said Prof. Davidson.

This latest scientific validation of the yet to be realised power of meditation is naturally welcome news for all practitioners of Vipassana meditation. For most of us, it is also no surprise.