User talk:TimBowe
From Wikipedia, the free encyclopedia
Neuroscientific perspectives
Olaf Blanke studies There is now an ongoing research project into the neuroscience of OBEs being undertaken by Olaf Blanke in Switzerland. This line of research acknowledges the experiences as reported by the subjects as valid. That is, people really do feel as if they have left their body. However, researchers have found that it is possible to reliably elicit such experiences by stimulating regions of the brain called the right temporal-parietal junction (TPJ; a region where the temporal lobe and parietal lobe of the brain come together).[citation needed]
Olaf Blanke and his collaborators in Switzerland [3] have explored the neural basis of OBEs by showing that they are reliably associated with lesions in the right TPJ region[6] and that they can be reliably elicited with electrical stimulation of this region in a patient with epilepsy [7]. These elicited experiences, may include perceptions of transformations of the patient's arm and legs (complex somatosensory responses) and whole-body displacements (vestibular responses), all of which are commonly reported in OBEs.[citation needed]
In neurologically normal subjects, Blanke and colleagues then showed that the conscious experience of the self and body being in the same location depends on multisensory integration in the TPJ. Using event-related potentials, Blanke and colleagues showed the selective activation of the TPJ 330-400 ms after stimulus onset when healthy volunteers imagined themselves in the position and visual perspective that generally are reported by people experiencing spontaneous OBEs. Transcranial magnetic stimulation in the same subjects impaired mental transformation of the participant’s own body. No such effects were found with stimulation of another site or for imagined spatial transformations of external objects, suggesting the selective implication of the TPJ in mental imagery of one's own body[8]. In a follow up study, Arzy et al. showed that the location and timing of brain activation depended on whether mental imagery is performed with mentally embodied or disembodied self location. When subjects performed mental imagery with an embodied location, there was increased activation of a region called the "extrastriate body area" (EBA), but when subjects performed mental imagery with a disembodied location, as reported in OBEs, there was increased activation in the region of the TPJ. This leads Arzy et al. to argue that "these data show that distributed brain activity at the EBA and TPJ as well as their timing are crucial for the coding of the self as embodied and as spatially situated within the human body." [9]
Blanke and colleagues thus propose that the right temporal-parietal junction is important for the sense of spatial location of the self, and that when these normal processes go awry, an OBE arises.[10]
[edit] Michael Persinger studies Michael Persinger has undertaken similar research to Olaf Blanke using magnetic stimulation applied to the right temporal lobe of the brain, which is known to be involved in visuo-spatial functions, multi-sensory integration and the construction of the sense of the body in space. Persinger's research also found evidence for objective neural difference between periods of remote viewing in two individuals thought to have psychic abilities. Persinger undertook his research on Sean Harribance and Ingo Swann, a renowned remote viewer who has taken part in numerous studies.[11] Examination of Harribance showed enhanced EEG activity within the alpha band (8 - 12 Hz) over Harribance's right parieto-occipital region, consistent with neuropsychological evidence of early brain trauma in these regions. In a second study, Ingo Swann was asked to draw images of pictures hidden in envelopes in another room. Individuals with no knowledge of the nature of the study rated Swann's comments and drawings as congruent with the remotely viewed stimulus at better than chance levels, suggestive of some psi ability (also see parapsychology). Additionally, on trials in which Swann was correct, the duration of 7 Hz (alpha band) paroxysmal discharges over the right occipital lobe was longer. Subsequent anatomical MRI examination showed anomalous subcortical white matter signals focused in the perieto-occipital interface of the right hemisphere that were not expected for his age or history.
