Spiritual practices have been proposed to have many beneficial effects as far as mental health is concerned. The exact neural basis of these effects is slowly coming to light and different imaging techniques have elucidated the neural basis of meditative practices. The evidence though preliminary and based on studies replete with methodological constraints, points toward the involvement of the prefrontal and parietal cortices. The available data on meditation focus on activated frontal attentional network. Neuroimaging studies have shown that meditation results in an activation of the prefrontal cortex, activation of the thalamus and the inhibitory thalamic reticular nucleus and a resultant functional deafferentation of the parietal lobe. The neurochemical change as a result of meditative practices involves all the major neurotransmitter systems. The neurotransmitter changes contribute to the amelioration of anxiety and depressive symptomatology and in part explain the psychotogenic property of meditation. This overview highlights the involvement of multiple neural structures, the neurophysiological and neurochemical alterations observed in meditative practices.
Keywords: Anxiety and Psychotic states; Depression; Functional Imaging; Meditation; PSPL Deafferentation; Prefrontal Hypothesis; Spirituality.