Two double-blind studies were performed to examine magnetic field exposure effects and to determine the impact of temporal variation (continuous versus intermittent exposure) of magnetic field diurnal exposure on psychological and psychophysiological parameters in healthy humans.
Three exposure sessions of 30 min, i.e., sham, continuous, and intermittent (15 s ON/OFF cycles) magnetic field conditions, were involved. Each subject participated in all sessions, which were spaced at one week intervals.
In experiment 1, 21 healthy male volunteers were studied (ten subjects were exposed at 13:30 h, and 11 subjects were exposed at 16:30 h). Eighteen of the 21 volunteers took part in experiment 2, undertaken to better understand the data related to information processing. Exposure time was at 13:30 h.
|Setup||Subjects were seated in the exposure facility with their heads placed in the magnetic helmet.|
|Additional info||The helmet was formed by six Helmholtz coils distributed in three orthogonal directions. During the exposure one vertical and one horizontal pair of coils were energized.|
Experiment 1: Statistically significant changes in the amplitude of event-related potentials were revealed after magnetic field exposure in the dichotic listening task.
Experiment 2: The analysis of the data again revealed significant amplitude changes of the event-related potentials recorded in the dichotic listening task. Moreover, they demonstrated event-related potentials latency and reaction time slowing in the oddball paradigm. These data also indicate that a low level 50 Hz magnetic field may have a slight influence on event-related potentials and reaction time under specific circumstances of sustained attention.