Since I cannot get the full text of Urgesi et al’s article and has to rely on what is freely available on the net, here’s a nice review of the article over at Neurophilosophy. I think Urgesi et al’s article is an important study that can be a source of inferences in various disciplines, such as the one mentioned in my previous blog. Below are some of the points raised by Neurophilosophy regarding the article:
It is well documented that posterior regions of the parietal lobe are involved in various aspects of bodily self-awareness, including the perception of one’s body in relation to its surroundings. Damage to the left posterior parietal cortex, for example, causes deficits in awareness of the spatial relationships between different body parts; lesions in the junction of the temporal and parietal lobes in the right hemisphere are associated with delusions in which patients deny owning their limbs; and damage to the left and right temporo-parietal junction can cause the illusion that the self is located within the extrapersonal space surrounding the body and out-of-body experiences, respectively.
The authors describe their findings within this context. Ablation of tissue near the temporo-parietal junction, especially in the inferior parietal lobe, causes a reduced sense of bodily awareness, so that the boundary between self and non-self become blurred. This detachment from the body increases the patients’ propensity for mystical experiences. Supporting this conclusion, earlier work has shown that the mystical experiences of Tibetan Buddhist monks and Carmelite nuns are associated with altered parietal lobe activity.
One major drawback of the study is that it is based entirely on the patients’ own reports of self-transcendence. The results would have been more rigorous if based on an objective measure of the phenomenon. Furthermore, self-transcendence is a vague concept which means different things to different people. The authors’ definition of it is therefore somewhat narrow, as there is more to this trait than the three aspects measured by them. It is also unlikely that a trait such as self-transcendence can be localized to just two regions of the brain. Likewise, spirituality is an extremely complex phenomenon of which self-transcendence is but one aspect.