Over the centuries mystics and spiritual leaders have reported an experience which they perceived as utterly and unquestionably real -- an experience of God and the Absolute. Today scientists are working on the neurology of such spiritual experiences. What can this research tell us about the roots of our spiritual and religious heritage? Andrew Newberg and Eugene D'Aquhi, two medical doctors, studied the brains of Tibetan Buddhist meditators and Franciscan Catholic nuns. They found that the events the meditators considered spiritual were indeed associated with observable neurological activity. The research was based upon the fact that increased blood flow to a given part of the brain correlates with heightened activity in that particular area, and vice versa. For the measurements they used a high-tech brain imaging tool, the SPECT camera (single photon emission computed tomography). At the transcendent peak of the spiritual state, the subject tugged on a string. Radioactive dye was released into an intravenous catheter in their arm and SPECT images of their brain were recorded.

Medical research has shown that every event that happens to us or anything we do including our thoughts and emotions can be associated with activity in one or more specific regions of the brain. The researchers found that during spiritual activities the front part of the brain became more active. This area reflects focused attention and concentration, and is considered the neurological seat of the will. In addition, the spiritual state produced a sharp reduction in the activity level of the posterior superior parietal lobe, or "orientation association area" (OAA). One job of the OAA is to draw a sharp distinction between you and everything else; between you and not-you. The second job is to give you the ability to experience a "three-dimensional body" and to orient that body in physical space.

The OAA is an area of the brain that never rests. It requires a constant stream of sensory information to do its job well. So what would be the effect to our perception of reality when the OAA is deprived of sensory input as a person enters a deep spiritual state? The perception of discrete objects would cease, there would be no sense of space or the passage of time, no line between the self and the rest of the universe. In fact, there would be no subjective self at all; there would only be an absolute sense of unity -- without thought, without words, and without sensation. The mind would exist without ego in a state of pure, undifferentiated awareness. Such unitary states are the transcendent goal of all spiritual paths! Unitary states range from the mildest to the most profound, and represent a span of a continuum depending upon the degree that the sensory input to the OAA is blocked. In addition to meditation and prayer such spiritual states can begin with physical activity -- any repetitive rhythmic behavior causes the orientation area to be blocked from neural flow. Of course, the process can be set in motion by nothing more tangible than the mind willing itself toward God.

The nerve cells in all living things are very similar. Neurologically, the change over millions of years of evolution is the complexity. This is what separates human brains from those of the toad, the cat, or the monkey. This increased complexity permits an organism to perceive and react more effectively and with greater versatility to their environment. The most recently evolved region of the human brain, the neocortex, enables us to create language, art, culture, and myth. The neurons or nerve cells in our brains plus some in the heart and elsewhere serve as map makers for our perceptions of reality. They map the geography of our body, and of the events that take place within that geography -- this includes both information received directly by our senses and "non-local" input, i.e., input from the Absolute. How did the brain circuitry for transcendence evolve? The researchers believe the neurology of transcendence borrows the neural circuitry of sexual response. The neurological structures and pathways involved in transcendent experience originally evolved to link sexual climax to the powerful sensations of orgasm.

But are we really perceiving a higher spiritual reality -- an encounter with God? What we think of as reality is nothing more than a rendition of reality that we create in our brain. The floor beneath your feet, the chair you're sitting in, the paper you hold in your hands may all seen unquestionably solid and real, but they are known to you only as secondhand neurological perceptions, as blips and flashes racing along the neural pathways inside your skull. If you were to dismiss spiritual experience as "mere" neurological activities, you would also have to distrust all of your own brain's perceptions of the material world. However, assuming you trust your perceptions of the physical world, you have no rational reason to declare that spiritual experience is a mental fiction. If God does indeed exist, the only place he can manifest his existence would be in the tangled neural pathways and physiological structures of the brain. Our reality emerges from our brain, and while the SPECT imaging research doesn't prove the existence of God or the Absolute, it does indicate that these spiritual states are as real as any other brain states. Thus mystical experiences are biologically and scientifically real, and play an evolutionary roll in our survival.