As a long time meditator and neuroscientist, my interest in the effect of meditation on brain function is both personal and professional. The benefits meditation has brought to my life mirror first-person accounts of other meditation practitioners--basically, a sense of greater peace and more joy.

In addition to being even-minded in the midst of life's challenges, many meditators describe having experiences that might be called mystical--and not just in the state of meditation but also after their session of meditation has ended. Some individuals say that their awareness has been expanded beyond the stretch of their five senses; some say they experience the world to be luminous or to scintillate with light.

One morning after my own daily meditation, as I lay back quietly, my awareness floated to the top of the room, near the ceiling, and I had an amazing sense of freedom and joy. This lasted for a few moments, and then, gradually, my awareness descended once again into my body. As a neuroscientist, I didn't know how to understand this experience. My materialist scientific background does not accept that such an experience could be anything more than my imagination. Yet, in sharing this experience with others, I found that it was not unique to me. And when I explored the literature on meditation from a variety of spiritual traditions, I found that experiences like this have been recorded for years.

In the world of science, this sort of experience, of meditation or any other activity, is defined as subjective. This means it's from a first-person perspective. First-person accounts are not given credence in scientific literature, and any first-person report of mystical or paranormal experiences--which is what these experiences of luminosity or awareness beyond the bounds of the senses are--do not fall within the scope of Newtonian science. This strictly cause-and-effect materialistic view is the traditional scientific perspective. According to Newtonian science, such experiences are seen, at best, as visual or auditory hallucinations or, worse, as psychotic episodes. One group of scientists has noted, "There is a risk that in the clinical application of meditative practices--where meditation training is divorced from its traditional... contexts--reports of such experiences could be misdiagnosed as a more serious physiological or psychological disorder."

By definition, the scientific method requires objective or third-person data that can be verified and replicated in an experimental setting. Thus, all first-person experience is excluded from traditional scientific inquiry.

As a scientist, I have to wonder if it's valid to discount automatically experiences that have been reported by thousands over hundreds of years and from cultures around the world. Yet, if we were to include subjective experiences in our analysis of the effects of meditation, how could we test for the validity of such experiences? How would we measure them?

Before addressing these questions, let's look at the insights objective science offers regarding meditation, brain function, and consciousness. Numerous carefully designed laboratory experiments measuring the effects of meditation on health and well-being have demonstrated significant positive effects--an increased sense of well-being, lowered anxiety, improved attentional focus, and heightened immune function.

Meditation even alters the structure of the brain. Harvard neuroscientist Sara Lazar studied this question, recruiting people who were, as she said, "just average Joes who, on average, practiced meditation 30 or 40 minutes a day." Using an MRI (magnetic resonance imaging) scanner, Lazar determined that the meditators in her study retained thickness in the parts of the prefrontal cortex associated with memory and executive decision-making, while in the control group--non-meditators--these parts of the brain were thinner in the older participants. This suggests that meditators are better able to retain memory and decision-making functions as they get older.

One of my own studies on meditation compared the attentional abilities of three groups of adult practitioners--meditation, tai chi (a form of moving meditation), and aerobic exercise--to sedentary adults. We asked the participants to play a computer game that required intense focus, involving pressing keys quickly and responding to constantly changing rules. The meditators and tai chi practitioners were almost twice as proficient as those of the sedentary control group, and the aerobic exercisers were about halfway in between. Such research demonstrates that meditators are like athletes within the sphere of the mind.

As compelling as I find these objective accounts on the effects of meditation on brain function, none of them address my own keenest interest in meditation: the experiences of meditators and especially their experiences of expanded awareness.

I certainly do not want to dismiss the value of the experiments on meditation done by my colleagues, my graduate students, or myself. This research brings a clearer understanding of the broad health benefits of meditation. What these studies may also do, however, is to limit to the realm of the merely physical an endeavor that has the potential to offer access to higher states of consciousness.

The Nobel laureate quantum physicist Erwin Schroedinger addresses this quandary with great eloquence:

The scientific picture of the real world around me is very deficient. It gives a lot of factual information... [but] it cannot tell us a word about red and blue, bitter and sweet, physical pain and physical delight; it knows nothing of beautiful and ugly, good or bad, God and eternity. So, in brief, we do not belong to this material world that science constructs for us... the scientific worldview contains of itself... not a word about our own ultimate scope or destination.

This is precisely my concern. Scientific research on meditation may be able identify which neurons are activated in meditative states, but this is insufficient. Within our studies, we need to include the first-person perspective and to examine heightened awareness during meditation. This might involve a new way of categorizing brain function. It might require us to entertain the possibility that expanded awareness is super-normal and that there are, indeed, expanded states of consciousness that are currently unacknowledged by science.