Although it is well established that all behaviors and experiences, spiritual or otherwise, must originate in the brain, information on the causative link between brain activity and spirituality is lacking. Neuroimaging studies have associated activity within a large network in the brain that connects the frontal, parietal, and temporal cortexes with spiritual experiences, but researchers have been unable to establish a causative relationship between such a network and spirituality.

In order to establish that relationship, researchers studied the personality trait self-transcendence (ST), which is thought to be a measure of spiritual feeling, thinking, and behaviors, in patients before and after surgery to remove a brain tumor.

In a study appearing in Neuron, the team combined analysis of ST scores obtained from brain tumor patients before and after they had surgery to remove their tumor, with advanced techniques for mapping the exact location of the brain lesions after surgery. "This approach allowed us to explore the possible changes of ST induced by specific brain lesions and the causative role played by frontal, temporal, and parietal structures in supporting interindividual differences in ST," says researcher Dr. Franco Fabbro from the University of Udine.

Results revealed that selective damage to the left and right posterior parietal regions induced a specific increase in ST. "Our symptom-lesion mapping study is the first demonstration of a causative link between brain functioning and ST," says lead author Dr. Urgesi. "Damage to posterior parietal areas induced unusually fast changes of a stable personality dimension related to transcendental self-referential awareness. Thus, dysfunctional parietal neural activity may underpin altered spiritual and religious attitudes and behaviors."

These results may even lead to new strategies for treating some forms of mental illness. "If a stable personality trait like ST can undergo fast changes as a consequence of brain lesions, it would indicate that at least some personality dimensions may be modified by influencing neural activity in specific areas," suggests Dr. Salvatore M. Aglioti from Sapienza University of Rome. "Perhaps novel approaches aimed at modulating neural activity might ultimately pave the way to new treatments of personality disorders."

Citation: Urgesi et al., 'The Spiritual Brain: Selective Cortical Lesions Modulate Human Self-Transcendence', Neuron, February 2010, 65 (3), 309-319; doi: 10.1016/j.neuron.2010.01.026