Electronic Thesis and Dissertation Repository


Master of Science


Medical Biophysics


Dr Alexandre Legros, Dr Alex W. Thomas


Extremely low frequency (ELF, < 300 Hz) magnetic fields (MFs) have been reported to modulate human cognitive performance. However, little research has investigated MF exposures comparable to the highest levels experienced in some occupations. This research evaluated the impact of a 60 Hz, 3 mT MF on human cognitive performance. Ninety-nine participants completed the double-blind protocol performing a selection of psychometric tests under two consecutive MF exposure conditions (exposure vs. no exposure). A significant interaction effect on a working memory test (digit span forward - F=5.21, p<0.05) revealed an absence of expected improvement associated with test repetition for both exposure groups compared to the control group. The memory test results suggest that MF exposure may be able to modulate the performance improvement usually observed with practicing a task. It is speculated that an ELF MFs may interfere with the neurophysiological processes responsible for this short-term learning effect.