Spirituality, although it has always been surrounded by mysticism and uncertainty, has been an integral part of the human psyche since the emergence of the modern man (Buckman 31). There is evidence that even Homo sapiens from the Paleolithic era (ca. 120,000 BC - 8,000BC) believed in a spiritual world. These archaic human beings engaged in mortuary practices similar to modern ones, burying their dead in sleeping positions and surrounding them with ritual artifacts. Intricately fashioned jewelry and symbolic paintings suggest their belief in an afterlife, while precautions such as ritual decapitation (to prevent the deceased's return from the afterlife) attest to their fear of the spiritual world (Clark 54).Although the cognitive capabilities of early humans were still far more primitive than their modern counterparts, there is a similarity in the region of the brain that is responsible for these emotions (Joseph 106-107).
This region consists of the limbic system and inferior temporal lobe. Different stimuli activate these nuclei can produce feelings of spiritual significance. Furthermore, evidence of connections between these stimuli and religious fervor is apparent throughout history. Spiritual and religious feelings and beliefs that human beings have been experiencing can be explained as responses to environmental and emotional stimuli in the limbic system and inferior temporal lobe.
Together, the limbic system and inferior temporal lobe have been found to provide foundations for mystical, spiritual, and religious experiences -- the perception and hallucination of ghosts, demons, and spirits and the belief in demonic or angelic possession (Motluck 7). The limbic system is composed of three major nuclei: the hypothalamus, the amygdala, and the hippocampus. These nuclei are "primary in regard to memory, the production of visual imagery, and the expression and perception of most aspects of emotion (including religious ecstasy).