Study type: Medical/biological study (experimental study)

Physiologically patterned weak magnetic fields applied over left frontal lobe increase acceptance of false statements as true. med./bio.

Published in: Electromagn Biol Med 2008; 27 (4): 365-371

Aim of study (acc. to author)

To test whether a weak magnetic field pulsed over the left prefrontal brain region at the moment of accepting or refuting a statement could increase the likelihood of later accepting a false statement as true.

Background/further details

The first stages of cognitive processing require the acceptance of all information as "true". This is followed by either accepting or rejecting this assumption. The left prefrontal brain region is typically associated with decision making and judgement.
25 men and 25 women were assigned to 5 experimental conditions including 4 groups with specific electromagnetic exposure patterns (25 Hz, 50 Hz, burst-firing, 7-10 Hz) and one sham exposure group.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 25 Hz
Modulation type: pulsed
Exposure duration: 20 ms on - 20 ms off, for 1 s
Exposure 2: 50 Hz
Modulation type: pulsed
Exposure duration: 10 ms on - 10 ms off, for 1 s
Exposure 3:
  • unspecified
Modulation type: pulsed
Exposure duration: continuous for 1 s
Exposure 4: 7–10 Hz
Exposure duration: continuous for 1 s

Exposure 1

Main characteristics
Frequency 25 Hz
Type
Waveform
  • rectangular
Exposure duration 20 ms on - 20 ms off, for 1 s
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Setup pair of solenoids held over the subject's left eyebrow
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT minimum - - -
magnetic flux density 10 µT maximum - - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
  • rectangular
Exposure duration 10 ms on - 10 ms off, for 1 s
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT minimum - - -
magnetic flux density 10 µT maximum - - -

Exposure 3

Main characteristics
Frequency
  • unspecified
Type
Exposure duration continuous for 1 s
Modulation
Modulation type pulsed
Additional info

burst firing - for more information see [Richards 1993]

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT minimum - - -
magnetic flux density 10 µT maximum - - -

Exposure 4

Main characteristics
Frequency 7–10 Hz
Type
Waveform
  • rectangular
Exposure duration continuous for 1 s
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 10 nT - - - -

Reference articles

  • Richards PM et al. (1993): Modification of activation and evaluation properties of narratives by weak complex magnetic field patterns that simulate limbic burst firing.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

When the statements were presented again, the groups who had received the burst-firing or 25 Hz pulsed magnetic fields during the refutation process declared about twice the number of "false" statements as "true" compared to those exposed to the 50 Hz field or sham exposure. The treatments did not significantly affect the numbers of "true" statements accepted as "false".
The results suggest that magnetic field exposure during the refutation process of what one has been told or has heard can increase the probability that a person will accept a "false" statement as "true". Electromagnetic fields might affect physiological processes and brain electric states that lead to a disruption of the refutation process.

Study character:

Study funded by

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