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It can be difficult to unobtrusively track the neuronal activity of those in intense states of meditation or prayer without jolting them back into everyday perception. However, using Single Photon Emission Computed Tomography, or SPECT, scientists Newburg and DíAquili were able to track neuronal activity in skilled meditators without disturbing them. With an intravenous tube in their arm, each meditator focused intently on a single, usually religious image until they achieved their familiar meditative sense of ìonenessî. When each meditator felt this sense, they tugged on a string to alert the researchers, who then injected a radioactive tracer into the intravenous line. The tracer bound to the brain regions where blood flow was highest. A scanner then made a snapshot showing the regions with the most blood flow, which indicates neuronal activity. (3).
Since the meditators were focusing intently, the Prefrontal Cortex, associated with attention, lit up. But more strikingly, the parietal lobes showed very little activity. Part of the cerebrum, the parietal lobes are associated with the orientation of the body in space and processing information about time and space. More specifically, the left superior parietal lobe creates the perception of the physical bodyís boundaries. The right superior parietal lobe creates the perception of the physical space outside of the body. (3). Blocked off from neuronal activity, the parietal lobe cannot create a sensation of boundary between the physical body and the outside world, which may explain the meditatorsí sense of ëonenessí with the Universe. Since the parietal lobes were also unable to perform their usual task of creating our linear perception of time, meditators achieved a sensation of infinity and timelessness.
Dr. Micheal Persinger claims that most people can experience timelessness and even meet God simply by strapping on his unique helmet. Persingerís inspiration for this contraption came from studying temporal lobe epileptics, whose rare form of epilepsy causes them to have temporal lobe seizures during which they report having intense mystical experiences. (1). This ëGod Helmetí gently creates miniature-versions of temporal lobe epileptic seizures by causing short-lived increases in the neuronal firing in the temporal lobes. (1). Patients sit reclined, isolated from sound and with eyes covered. The helmet is strapped to the head and currents shoot from its solenoids into the brain, generating a low-frequency milligauss magnetic field. The magnetic fieldóno stronger than that produced by a computer monitorórotates anticlockwise in a pattern around the temporal lobes. (2). Researchers can cause the helmetís currents to create micro-seizures in specific regions. When currents are aimed into the limbic regions, subjects report experiencing extreme emotions, distortions in their body image and sensations of forced motion. When the temporal lobes are stimulated, subjects often report specifically religious, dream-like hallucinations, and four out of five subjects report sensing a ìspectral presenceî in the room with them. (2).
Why would such sensations arise when the limbic and temporal lobe regions are stimulated? Can we make neurological sense of the ëspectral presenceí and religious visions? Inside the temporal lobes is the temporal cortex, the left hemisphere of which Persinger suggests is responsible for our ësense of selfí. In most people, there is fairly equal neuronal activity in both the right and left temporal cortexes. However, when activity gets out of synchó say, by strapping on Persingerís helmetóPersinger argues that the left hemisphere interprets the right hemisphere as a separate ìsensed presence,î or sometimes as God. (1). This usually happens in conjunction with extra stimulation in the limbic system, where the hippocampus (associated with equilibrium and memory) and the amygdala (associated with emotion) reside. This region also controls certain aspects of movement. (4). When this region is stimulated with Persingerís helmet, it makes sense that subjects experience strong emotions and sensations of forced movement. The limbic system also labels specific eventsósuch as the sight of loved onesówith significance. (2) . The Limbic systemís unusual activity during spiritual experience may help to associate feelings of deep awe and emotional significance with the experience of a ìsensed presence,î a oneness with the Universe, and a sense of infinity.
Miniature temporal lobe seizures occasionally occur in otherwise ëhealthyí people without the aid of Persingerís helmet. Persinger tested subjects with tendencies for mystical/spiritual experience, and found that they tended to have subtle hemispheric mismatch all the timeóeven when not seizuring. (1). Potential triggers for seizures include fatigue, high altitude, low blood sugar, personal crisis, anxiety and other physiological stressors. Not everyone who climbs Mount Everest without having eaten enough trail-mix will see God (although there are many from whom we never had a chance to find out.) But those who do may have been predisposed for such an encounter by the interhemispheric circuits in their temporal lobes.
Obviously, there is a wide range of spiritual connection that one can experience without Persingerís helmet or Zen meditation. But most spiritual experiences appears to involveómore or less dramaticallyóthe same parts of the brain. Some people may be ëhard-wiredí to have such brain-region- specific experiences more frequently, and to varying degrees of intensity. One study suggests that people with mystical experiences are more connected to their subliminal unconscious, and are more prone to dissociation. (3). (3) This dissociation may correlate with the dissociation between the temporal lobes.
A limbic region stimulated by music, dancing, or the chanting of religious ceremonies can trigger less intense spiritual experiences. These activitiesó though sometimes less dramatically than meditation or seizuresócan also cause the hippocampus to block neuronal activity to other parts of the brain, tagging them with special significance. This helps explain the transcendent experiences which some musicians report, or why chanting and ritual is so important to many religious traditions. Research on Alzheimerís disease also supports the limbic systemís involvement in spiritual experience: Alzheimerís cripples the limbic system and is characterized by a loss of religious interest. Also, neurosurgeons who stimulate the limbic region during surgery say their patients report having religious experiences. (2).
Skeptics claim that tracing the experience of God into the brainís hardwiringóand especially being able to create similar experiences with Persingerís helmetóproves that God is a figment of the imagination. They argue that no evidence indicates that a ìDivine Powerî externally imposes these experiences. (2). Some skeptics believe that temporal lobes may contribute to imagination and creativity, but that spiritual experience is a mental error akin to deja vu. David Noelle argues, ìHow can you trust such an experience when, through science, we can convincingly mimic the face of God?î (1).
Believers counter with the argument that if God exists, of course S/He/It would design the brain so that we could have some form of interaction. (2). Others argue that we can never know one way or the other and fault the human brainís limited conceptual abilities. They believe that all of our experiencesómystical or quotidianómust be judged as equal in that they are all perceptions of the brain. Itís difficult to say that one personís experience is more valid than anotherís. We can only judge how real our brainís conception of ërealityí is by using the brain (2)., and ërealityí is a disputable creation of our arguably faulty perceptual system.
According to neuronal activity in the brain, its perception of toe stubbing is as ërealí as its perception of transcendent, ineffable spiritual experiences. Newburg, of the findings of his studies, says: ìThe fact that spiritual experiences can be associated with distinct neural activity does not necessarily mean that such experiences are mere neurological illusions. Itís no safer to say that spiritual urges and sensations are caused by brain activity than it is to say that the neurological changes through which we experience the pleasure of eating an apple cause the apple to exist.î (2). The difference lies in the fact that most of us agree on the physical existence of an apple. Visions of Fatima are more difficult to describe, reproduce, hold in our hands and take a bite out of.
Neuroscientist Eleanor Rosch agrees with Zen practitioners that our everyday perception--even the mostly universal agreement on the existence of apples-- may be a useful fiction. (5). Rosch and research partner Christine A. Skarda suggest that the feelings of interconnectedness that people perceive during deep meditation may in fact be just as ërealí as the popular assumption that humans are separate beings. Our perception of separateness from the outer world may just be a handy ability that enables us to achieve certain sensations. The moments of ëonenessí we experience may be the recovery of a larger reality. (5).
The difference ñ and controversy ñ between the neural experiences of toe stubbing or apple eating and transcendent contact with God partially lies in the meaning and purpose that we ascribe to each experience. These meanings and purposes originate from the neural pathways of the very brain that we are trying to dissect. What can we trust other than our perceptions and the knowledge that they are limited? Believing that mechanisms within the brain prove the existence of God cannot be an act of reductionist science, but one of faith. And if one is so inclined or ëwiredí towards faith, research suggests that regular prayer or meditation lowers blood pressure and heart rate, and decreases depression and anxiety. (6). It may be an ëopiate of the masses,í but as opiates run, itís a pretty healthy one. Hell, it might even get us into heaven.
2) Holmes, Bob. ìIn Search of God.î New Scientist 21 April: 24
3 Begley, Sharon, Anne Underwood. ìReligion and the Brain.î Newsweek 7 May 2001: 50
4) The Humanizing Brain: Where Religion and Neuroscience, The Christian Century
5) Into the Mystic,Science News
6) Heffern, Rich. ìExploring the Biology of Religious Experience. ìNational Catholic Reporter 20 April 2001: 14
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