Ten healthy subjects (mean age of 23.8 years), 5 males and five females, were included in the study.
Subjects equipped with the EEG cap were seated in an armchair and provided with earplugs. Then, they were exposed to eleven conditions (sham exposure, 5 mT, 10 mT, 15 mT, 20 mT, 25 mT, 30 mT, 35 mT, 40 mT, 45 mT and 50 mT), respectively presented for 5 seconds. Each of the eleven exposure conditions was repeated for five times with the order being randomized. During exposure, subjects were asked to to keep their pointing finger position as stable as possible.
|Setup||head exposure system consisted of a 176-turn coil (16 layers of 11 turns each, 6 cm inner diameter and 22 cm outer diameter) made of hollow square copper wire cooled by circulating water; coil could generate the magnetic field without any perceptible noise or vibration|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||50 mT||maximum||measured and calculated||-||0, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 mT|
No significant modulations in postural tremor characteristics were found. However in EEG, a significant main effect for magnetic field exposure was found for electrodes covering the left primary somatosensory cortex (CP3 and CP5) suggesting a decreased µ waves power spectral density with increasing magnetic flux density. However, further analysis (Bonferroni correction) did not confirm the effects.
The authors conclude that this human pilot study did not show physiological tremor modifications but suggested a possible effect of 60 Hz magnetic fields in the high mT-range on the brain region related to tactile perception and further research is needed.