Medical/biological study (experimental study)

Evidence of a nonlinear human magnetic sense med./bio.

By: Carrubba S, Frilot 2nd C, Chesson Jr AL, Marino AA

Published in: Neuroscience 2007; 144 (1): 356-367

Aim of study (acc. to author)

This in vivo study was performed to detect possible evoked potentials in human EEG due to magnetic fields exposure (magneto-sensory potentials).

Background/further details

Seventeen clinically normal subjects (eight men, nine women, age range: 18-51) took part in this study. Magneto-sensory evoked potentials were determined by using a) recurrence analysis (linear and nonlinear determinism) and b) time averaging method (only linear determinism). As a positive control, a binaural 424 Hz tone (sound pressure level: 65 dB) was presented.

Endpoint

effects on the neurological system: mangeto-sensory evoked potentials

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: 2 s	magnetic flux density: 200 µT

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Exposure duration	2 s

Exposure setup

Exposure source	coil(s)
Setup	two sets of coils 65 cm apart; each set consisting of a circular coil with a radius of 26.1 cm and 21 turns and two square coils 48.3 cm side lenght and 85 turns and 66 cm side length and 120 turns
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	200 µT	-	-	-	-

Exposed system:

human
partial body: head

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: mangeto-sensory evoked potentials (EEG measurement from occipital, central, and parietal electrodes)

Investigated system:

investigation on living organism

Investigated organ system:

brain/CNS

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

Using the method of recurrence analysis, magneto-sensory evoked potentials in the signals from occipital derivations were found in 16 of the subjects. Magneto-sensory evoked potentials in the signals from the central and parietal electrodes were found in most subjects.
Using the method of time averaging, no magneto-sensory evoked potentials were detected in any brain region.

Study character:

medical/biological study
experimental study
full/main study
intra-subject design

Study funded by

not stated/no funding

Frilot 2nd C et al. (2011): Transient and steady-state magnetic fields induce increased fluorodeoxyglucose uptake in the rat hindbrain
Carrubba S et al. (2010): Numerical analysis of recurrence plots to detect effect of environmental-strength magnetic fields on human brain electrical activity
Marino AA et al. (2010): Simulated MR magnetic field induces steady-state changes in brain dynamics: Implications for interpretation of functional MR studies
Frilot 2nd C et al. (2009): Magnetosensory function in rats: localization using positron emission tomography
Carrubba S et al. (2009): The electric field is a sufficient physical determinant of the human magnetic sense
Carrubba S et al. (2008): Magnetosensory evoked potentials: consistent nonlinear phenomena
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