Medical/biological study (experimental study)

Increased feelings of the sensed presence and increased geomagnetic activity at the time of the experience during exposures to transcerebral weak complex magnetic fields med./bio.

By: Booth JN, Koren SA, Persinger MA

Published in: Int J Neurosci 2005; 115 (7): 1053-1079

Aim of study (acc. to author)

To investigate whether experiences of a "sensed presence" within an experimental setting were associated with concurrent, increasing geomagnetic activity.

Background/further details

The authors define "sensed presence" as the prototype for reports of noncorporal entities including gods, deceased family members and other ethereal forms. "Sensed presence" can be elicited by weak magnetic fields.
39 students (23 in study 1; 16 in study 2) were exposed. During the experiments a blindfold had been placed over the subjects eyes.
Study 1: Subjects were told to participate in a relaxation study where weak magnetic fields may be presented; the "sensed presence" was not mentioned.
Study 2: Subjects were told the purpose of the experiment was to discern if specific types of magnetic fields could affect the occurence of a "sensed presence".
Additionally, three-hour values of geomagnetic activity were obtained during, before and after the experiments, together with the average of the low and high values of the day before, the day of and after the experiment.

Endpoint

subjective experience

Exposure

- magnetic field
- geomagnetic field

Exposure	Parameters
Exposure 1: DC/static Exposure duration: continuous for 30 min	magnetic flux density: 1 µT minimum magnetic flux density: 2 µT maximum

Exposure 1

Main characteristics

Frequency	DC/static
Type	magnetic field
Exposure duration	continuous for 30 min

Exposure setup

Exposure source	solenoid
Setup	test person sitting on a chair in an acoustic chamber wearing a helmet; four sets of solenoids embedded on each side of the helmet; field delivered to opposed solenoid pairs for 0.5s; field rotated through the four pairs once every 2 s; field over the right hemisphere 10 - 30 % stronger than over the left
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1 µT	minimum	-	-	-
magnetic flux density	2 µT	maximum	-	-	-

Reference articles

Persinger MA (1999): Increased emergence of alpha activity over the left but not the right temporal lobe within a dark acoustic chamber: differential response of the left but not the right hemisphere to transcerebral magnetic fields

Exposed system:

human
partial body: head, right hemisphere

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: EEG (study 1 and 2)
cognitive/behavioral endpoints: psychometric data (three questionnaires on: 1. capacity to fantasize, 2. incidence of dissociation, 3. temporal lobe sensitivity) (study 2)
subjective experience: questionnaire (e.g. dizziness, "sensed presence", tingling sensations, pleasant vibrations through the body, detachment from the body, images along the left or right side of the visual field or body; questionnaire) (study 1 and 2)

Investigated system:

investigation on living organism

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

Study 1 and 2: The incidence of a "sensed presence" while being exposed to magnetic fields was moderately correlated with increased geomagnetic activity during the 3-hour period of the experiment.
Study 1: Except for a significant correlation between EEG measures and the geomagnetic activity the day before the experiment, there were no other significant correlations with "sensed presence" or geomagnetic activity.
Study 2: After applying a statistical correction procedure, the correlation between the reports of a "sensed presence" and the geomagnetic activity did a) not change after removing the influence of the factor "capacity to fantasize; b) decrease after removing the influence of the factor "incidence of dissociation"; and c) increase after removing the influence of the factor "temporal lobe sensitivity".
The results suggest that "sensed presence" is generated by right hemispheric processes that are enhanced by weak magnetic fields and that can be encouraged by increased global geomagnetic activity.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

Meli SC et al. (2009): Red light facilitates the sensed presence elicited by application of weak, burst-firing magnetic fields over the temporal lobes
St-Pierre LS et al. (2006): Experimental facilitation of the sensed presence is predicted by the specific patterns of the applied magnetic fields, not by suggestibility: re-analyses of 19 experiments
Persinger MA et al. (2005): A response to Granqvist et al. "Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak magnetic fields"
Larsson M et al. (2005): Reply to M.A. Persinger and S. A. Koren's response to Granqvist et al. "Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak magnetic fields"
Granqvist P et al. (2005): Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak complex magnetic fields
Booth JN et al. (2003): Increased proportions of sensed presences and occipital spikes with 1- and 10-msec. point duration of continuous 7-Hz transcerebral magnetic fields
Persinger MA et al. (2002): Experimental facilitation of the sensed presence: possible intercalation between the hemispheres induced by complex magnetic fields
Healey F et al. (1996): Enhanced hypnotic suggestibility following application of burst-firing magnetic fields over the right temporoparietal lobes: a replication
Randall W et al. (1991): The solar wind and hallucinations - a possible relation due to magnetic disturbances