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THERE has never been a better time to ask whether religion and science can ever coexist. Both are concerned with truth. For science, truth is constantly updated on the basis of theory backed by experiment, whereas for religion it is based on dogma in which we must have faith. Yet in 2005 the Dalai Lama, leader of one of the world’s great religions, was invited by thousands of neuroscientists to address their conference in Washington DC.

Before we bring down the wrath of Dawkins, the reason the Dalai Lama could appear there is simple: Buddhism is not like other religions. Because the Buddha said: “My words are to be accepted after examining them, not out of respect for me,” Buddhists are free to look askance at dogma and be open to the findings of science. This openness has fostered a long-standing interest in linking Buddhist teachings to science, in particular to the mysteries of quantum physics.

But why would Buddhists be attracted to neuroscience, a more down-to-earth field? Should neuroscientists return their interest? As a practising neuroscientist, my answer is: yes, up to point, but don’t expect too much.

“Why would Buddhists be attracted to down-to-earth neuroscience?”

The new books by Sharon Begley and B. Alan Wallace are the latest of a recent crop touching on the links between Buddhism and neuroscience. Don’t pay too much attention to their covers or titles. Train Your Mind, Change Your Brain is not marketing some dubious New Age therapy but is a clearly written account of recent discoveries about brain plasticity as presented by leading neuroscientists at meetings with the Dalai Lama. Contemplative Science, on the other hand, tells us nothing about the brain but castigates scientists for their materialism and their failure to develop tools for studying the mind. It also argues for building on Buddhist practices by setting up a subdiscipline of contemplative science – a bad idea, for reasons that will become obvious.

Why is the Dalai Lama (who wrote the foreword to Begley’s book) interested in brain plasticity? Begley has some clear answers. Until recently, neuroscientists believed the adult brain’s structure was irrevocably fixed. Then research into the brains of songbirds showed they expand each year during the nesting season as the birds perfect their songs, and then shrink again in winter. Similar expansion has been seen in jugglers’ brains and in London taxi drivers acquiring “the knowledge” – their “internal map” of the city.

This plasticity does not simply involve an increase in the size of brain regions that are intensively used. It also turns out that brain regions can change their function. If you are born blind, say, your visual neurons will not remain idle: in fact, you can be trained to “see” by attaching a video camera to a device that stimulates your tongue with a pattern of points corresponding to the images. After training, stimulating the tongue causes activity in visual neurons. If these neurons are stimulated directly, you will not see flashes, but feel tingles in your tongue.

These results are not only dramatic evidence of plasticity in adult brains but also demonstrate the intimate relationship between brain and mind, Begley reminds us. They show how changes in brain structure and function influence our conscious experience.

What about the mind influencing the brain? This is what really excites the Dalai Lama. Every year or two, at his base in Dharamsala, northern India, he hosts discussions with neuroscientists, and in 2004 the subject was neuroplasticity. The Dalai Lama told his visitors: “I am interested in the extent to which the mind itself, and specific subtle thoughts, may have an influence on the brain.” Behind this lies a deeper question about the relevance to science of the meditative practices that form a major part of Tibetan Buddhism.

So could intensive practice in meditation affect the brain? Might meditation prove a useful adjunct to cognitive behavioural therapy in treating mental disorders, for example? Such a link is in fact already being studied in research centres worldwide.

As to brain plasticity and how far the mind affects the brain and body, there is evidence that just imagining practising a skill can improve that skill. For example, if for about 10 minutes a day you imagine moving your little finger, after four weeks its strength can increase by 22 per cent.

How can we understand this link between the mental and the physical? This is where I part company with the neuro-Buddhist approach. Wallace, in his book, repeatedly emphasises the difference between the objective physical world and the subjective mental world. He says we have direct contact with the physical word through our senses and through such scientific instruments as telescopes. Meanwhile, he argues, our contact with the non-material mental world can only come through introspection. Scientists, he complains, have expended little effort on developing the powers of introspection. In contrast, through their meditative practices, Buddhists have built up such an impressive body of expertise in introspection that Wallace believes they might transform the scientific study of the mental world.

I disagree. I believe there is a much more basic approach to the study of the physical and the mental than Wallace – or Begley – would have us believe. For me, the question is not about how science or Buddhism approaches these problems, but how each individual acquires knowledge of both the everyday physical world (in which I successfully reach for my glass of wine), and the everyday mental world (in which I successfully anticipate your wish for a glass).

The obvious answer is that we use our brains and our sense organs to obtain this knowledge. From this perspective, there is no difference between the physical and the mental. The problem with the mental world is that I can never get inside your mind to check whether I have correctly inferred your wishes. But, as the philosopher Immanuel Kant pointed out, we have the same problem with the physical world: we can never check that our sensory experiences resemble it since we have no independent means of knowing it.

Our brains solve both these problems in the same way, but, like most brain work, largely without our awareness. Our brains are continually constructing models of the world and making predictions from them. If I think there is a wine glass in front of me, my brain predicts how I can move my arm to reach it and how it will feel when I touch it. If my predictions are wrong, if it is warm sake not chilled wine, I adjust my model. When errors in my brain’s predictions are sufficiently tiny, then I have a good model of the world.

It is this model of the world I am aware of, not the world itself. Is this model true? It doesn’t matter because as long as my brain can successfully predict what is going to happen next, I will survive.

I can use the same system in the mental world. I predict what you are going to do or say, and adjust my model of your mind on the basis of how good my predictions turn out to be. But unlike the physical world, you are also making a model of my mind, and by aligning each other’s models through prediction we can communicate ideas. It is only when people can share models of the world that we can wonder about the truth of these models.

Some models are better than others because they make better predictions and so are closer to the truth. This is why I find it strange that both these books say so little about interactions between people. It is only by studying interacting minds, rather than meditating minds, that we are going to make any progress in such difficult areas as consciousness and free will.