The Neuroscience of Spirituality

In the last decade, a number of studies have shown the success of spiritual medicine. These studies come from a wide number of fields and deal with many aspects of religious and spiritual practice. A recent study by Koenig et al (1999), looking at a population of nearly four thousand 65 year-old people over a six-year period, was able to show that those who go to church at least once a week are more likely to be alive after six years. Another study has shown the effect of church attendance on the immune system. Again, over 65 year olds who went to church at least once a week had lower levels of interleukin 6. Interleukin 6 is a cytokine involved with the inflammatory process and lower levels of this immune protein suggest an up-regulation of the immune system. Koenig et al. (2001a) in their Handbook of Religion and Health show in tabular form the different factors involved in susceptibility to disease and the importance of having a religious or spiritual belief. Many of these factors can be influenced by the behaviours which flow from an active religious faith, for example the limitation of self damaging behaviours such as smoking, drugs and alcohol, the social support network involved in religious belief and attendance at church and church services. A strong faith, positive relationships and positive thinking upregulate the immune system, reducing the risk of cancer, improving general health and protecting the cardiovascular system. The field is now so large that it is not possible to review the whole area. I will, however, look in detail at some studies relating to immune system functioning and cardiovascular parameters. Azari et al. (2001) looked at blood flow changes during religious practice. They studied a group of six subjects who had had a spontaneous religious conversion and compared them with subjects who had had no such experience. There were three conditions in the study. The first was reading a psalm, which induced strong religious feelings; secondly, a nursery rhyme, which induced happiness, and thirdly, reading from the telephone directory. A PET scan measuring blood flow was taken in these three conditions and the results show that there were a number of changes specific to the experience of religious feelings. The religious condition showed significantly increased flow in the pre-SMA (supplementary motor area), in the DLPC (right dorsolateral prefrontal cortex) and in the right pre-cuneus. They suggest that activity in the pre-SMA supports the preplanning of motor acts, particularly those that are involved in religious schema. The pre-cuneus, they argue, is linked to visual working memory, and the DLPC with memory retrieval. They also suggest that the DLPC could be involved in the monitoring of thought. It is difficult to argue that these changes are specifically related to the experiencing of religious feelings. However, it is clear that there is a difference between the religious and the control group. But as only six subjects were involved, replication of this study is needed to confirm its findings. A single case study has been carried out by Puri et al. (2001) in a patient with schizophrenia suffering from religious delusions. They measured cerebral blood flow by PET examination and repeated this when the subject was improved. They argued that the effects of the drugs he had been given are known and that they could not affect the results of PET scan examination. They showed that there was an increase in left frontal blood flow at the time of the religious delusions, and also some increase in left anterior temporal flow. They argued that these two areas might be involved with religious beliefs. The increase in left temporal blood flow during the religious delusional state is congruent with much of the epilepsy literature. The authors suggest that changes in the DLPC may be related to attention.