Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6282336 | Neuroscience Letters | 2014 | 5 Pages |
â¢Enhanced interhemispheric temporal lobe coherence occurred with increased geomagnetic activity.â¢The threshold for electroencephalographic changes was similar to those associated with subjective experiences.â¢Major coherence occurred within the alpha activity range.â¢Differences in left/right parahippocampal activity were correlated with increased geomagnetic activity.
Interhemispheric coherence for 19 channel EEG activity collected over a three year period from 184 men and women who relaxed in a quiet, darkened chamber showed significant increased coherence between caudal temporal regions for the 11Â Hz frequency band during increased (>â¼8Â nT) global geomagnetic activity at the time of measurement. Detailed analyses from source-localization indicated that a likely origin was the parahippocampal regions whose net differences at 10, 11 and 12Â Hz intervals were significantly correlated with geomagnetic activity. Analyses of residuals to obtain a “purer” measure of parahippocampal contributions indicated that interhemispheric temporal lobe coherence across unit increments between 1 and 40Â Hz revealed the most statistically significant peaks at 7.5Â Hz and 19.5Â Hz. These weak but reliable correlations between global geomagnetic activity and the degree of inter-temporal lobe coherence for normal people relaxing in a dark, quiet area are consistent with the results of multiple studies indicating that intrusive experiences such as “presences” or “hallucinations” are more frequent when global geomagnetic activity increases above â¼15-20Â nT.