The spiritual experiance

Most scientific literature asserts that spirituality is a product of the peculiar mechanisms of the brain.These interpretations make heavy use of neuroimaging techniques which crudely depict the activity of the brain during specific cognitive (thinking) processes. While most scientists regard spirituality as a consequence of brain activity, a slender group of neuroscientists are supportive of spiritual and religious ideology, or at least do not consider scientific explanations to be inconsistent with the (potential) presence of a genuine spiritual realm, including the existence of one or numerous supernatural agents.For the moment, however, causality will be overlooked; whether a supernatural agent stimulates a spiritual experience or not, there is no question that it manifests through the brain. This section will consider the evidence yielded from neuroimaging studies. These studies include neuroimaging analyses derived from techniques like positron emission tomography (PET), functional magnetic resonance (fMRI) imaging, and single positron emission computed tomography (SPECT). Each of these techniques provides information on neuronal (brain cell) activity through technological proxies such as the decay of radioactive isotopes injected into a subject, and the magnetic properties of a hydrogen nucleus excited by radio frequency radiation, which can map oxygenated blood flow. The data provided by neuroimaging have been central in revealing features of brain activity during various cognitive functions such as language, consciousness and even degree of religiosity.However, before it is possible to appreciate the findings of neuroimaging studies it is first instructive to review the brain structures under examination. The cerebral cortex of humans is relatively larger than those of other mammals and consists of four lobes: occipital, parietal, frontal and temporal. The temporal lobe is of particular interest to us because it houses the limbic system, which along with parts of the brain stem is amongst the oldest legacy of evolution. The limbic system is believed to be responsible for generating emotional reactions to the information it receives from the five sensory channels. Roughly, this response is subsequently shunted to the frontal lobes where the higher brain functions of conscious thought and goal-directed activity take over.Both the cruellest and the most exhilarating emotional experiences are an outcome of the primal reaction of the limbic system and the cautious rationality of the forebrain.  The limbic system also contains the hippocampus and amygdala. The former is believed to be involved with recording memories, particularly those with strong emotional content. Pathology in, or damage to the hippocampus, has been associated with changes to spiritual and religious beliefs, as well as changes to long-standing values.The amygdala is believed to play a senior role in coordinating unconscious emotional states. Noteworthy is its connection with the autonomic nervous system. Physiological responses to stressful emotional experiences like 'fight or flight' are largely orchestrated by the amygdala. In addition, because it is linked to the prefrontal cortex, it has a hand in the conscious awareness of emotion.