Several aspects of the human nervous system and associated motor and cognitive processes have been reported to be modulated by extremely low-frequency (ELF, < 300 Hz) time-varying Magnetic Fields (MF). Due do their worldwide prevalence; power-line frequencies (60 Hz in North America) are of particular interest. Despite intense research efforts over the last few decades, the potential effects of 60 Hz MF still need to be elucidated, and the underlying mechanisms to be understood. In this study, we have used functional Magnetic Resonance Imaging (fMRI) to characterize potential changes in functional brain activation following human exposure to a 60 Hz MF through motor and cognitive tasks. First, pilot results acquired in a first set of subjects (N=9) were used to demonstrate the technical feasibility of using fMRI to detect subtle changes in functional brain activation with 60 Hz MF exposure at 1800 μT. Second, a full study involving a larger cohort of subjects tested brain activation during 1) a finger tapping task (N=20), and 2) a mental rotation task (N=21); before and after a one-hour, 60 Hz, 3000 μT MF exposure. The results indicate significant changes in task-induced functional brain activation as a consequence of MF exposure. However, no impact on task performance was found. These results illustrate the potential of using fMRI to identify MF-induced changes in functional brain activation, suggesting that a one-hour 60 Hz, 3000 μT MF exposure can modulate activity in specific brain regions after the end of the exposure period (i.e., residual effects). We discuss the possibility that MF exposure at 60 Hz, 3000 μT may be capable of modulating cortical excitability via a modulation of synaptic plasticity processes.
fMRI full experiment 3000 microTesla part 1
fMRI full experiment 3000 microTesla part 1-10: MRI and fMRI DICOM images corresponding to the full study conducted with a 3000 microTesla exposure. These DICOM files have been produced by a Siemens 3T Verio (Siemens, Germany) MRI, as described in the paper. DICOM is a standard format for MRI images, and these can be analyzed with software packages such as BrainVoyager (Brain Innovation, The Netherlands), which we have used in the paper; or an open-access software package such as FSL (http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/). The analysis procedure for the fMRI data is fully described in the Methods section of the paper. DICOM files are available for each subject pre- and post-exposure, for each of the two tasks presented in the paper (finger tapping and mental rotation). Two tasks were used in this experiment: a mental rotation task and a finger tapping task. The subject who have properly conducted the mental rotation task and have been included in the analysis are: S02, S03, S04, S06, S07, S09, S10, S11, S12, S13, S14, S16, S17, S18, S20, S21, S23, S24, S25, S27, S29. The subject who have properly conducted the finger tapping task and have been included in the analysis are: S03, S04, S06, S07, S08, S09, S10, S12, S13, S14, S16, S17, S20, S22, S23, S24, S25, S26, S27, S29. Please feel free to contact the authors if further guidance is required.
fMRI full experiment 3000 microTesla part 2
fMRI full experiment 3000 microTesla part 3
fMRI full experiment 3000 microTesla part 4
fMRI full experiment 3000 microTesla part 5
fMRI full experiment 3000 microTesla part 6
fMRI full experiment 3000 microTesla part 7
fMRI full experiment 3000 microTesla part 8
fMRI full experiment 3000 microTesla part 9
fMRI full experiment 3000 microTesla part 10
fMRI_Pilot_1800_microTesla_DICOM part 1
fMRI_Pilot_1800_microTesla_DICOM part 1-2: MRI and fMRI DICOM images corresponding to the pilot study conducted with a 1800 microTesla exposure
These DICOM files have been produced by a Siemens 1.5T Avanto (Siemens, Germany) MRI, as described in the paper. DICOM is a standard format for MRI images, and these can be analyzed with software packages such as BrainVoyager (Brain Innovation, The Netherlands), which we have used in the paper; or an open-access software package such as FSL (http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/). The analysis procedure for the fMRI data is fully described in the Methods section of the paper. DICOM files are available for each subject pre- and post-exposure, for each of the two tasks presented in the paper (finger tapping and mental rotation). Please feel free to contact the authors if further guidance is required.
fMRI_Pilot_1800_microTesla_DICOM part 2