Effects of 5 s exposures to a 50 μT, 20 Hz magnetic field on skin conductance and ratings of affect and arousal

Abstract

This study investigated the effect of a weak magnetic field (50 microT, 20 Hz sinusoidal, 5 s duration) on concurrent perceptions of visual stimuli. Subjects were seated between Helmholtz coils and gave post-exposure ratings for the affective content and arousing nature of presented images. They were blind as to the presence or absence of a simultaneously presented field. Skin conductance and arousal ratings did not show significant differences between experimental and control conditions, but the affective content rating did (P = 0.041), with the images viewed under field exposure being rated as having a more positive affect. Such measures might thus be useful as additional indicators of magnetic field detection. A post-hoc analysis of skin conductance profiles showed that 48% of subjects exhibited a lowering of skin conductance during field exposure, 34% exhibited no apparent reaction, and 17% exhibited an increase. Overall ratings given by each of the groups appeared to relate to these physiological profiles.

An investigation into alleged ‘hauntings’

“…These results provide some support for the controversial theory that the presence of certain types of local magnetic elds may impact upon a range of psychological, psychophysiological and health-related variables (Korinevskaya, Kholodov, & Korinevskii, 1993;Voustianiouk & Kaufmann, 2000). A controlled laboratory study by Stevens (2001), for instance, showed psychological and physiological reactions to a changing magnetic eld of comparable magnitude to those measured in our two experimental venues. Even subtle psychological and physiological changes occurring in a context that might suggest paranormal events (e.g.…”

No influence of short-term exposure to 50-Hz magnetic fields on cognitive performance function in human

“…Moreover, since we did not investigated other elements of cognitive performance function, such as vigilance, attention, memory and intelligence ; Graham et al Gamberale et al (1989) 50-Hz EF+MF 3 kV/m+23 lT Visual (color-word) No Cook et al (1992) 60-Hz EF+MF 9kV/m+20 lT Visual (three lights) No (but accuracy increased) Whittington et al (1996) 50-Hz MF 100 lT Visual (two flashes) No (in easy task), and decrease (in difficult task) Preece et al (1998) 50-Hz MF 600 lT Visual (two words) No Crasson et al (1999) 50 Gamberale et al (1989) 50-Hz EF+MF 3 kV/m+23 lT Visual No Cook et al (1992) 60-Hz EF+MF 9 kV/m+20 lT Auditory and visual No Graham et al (1994) 60-Hz EF+MF (1) 6 kV/m+10 lT Auditory and visual (1) Increase (2) 9 kV/m+20 lT (2) No (3) 12 kV/m+30 lT (3) No Lyskov et al (1993) 45-Hz MF 1,260 lT Auditory No Podd et al (1995) 0.2-Hz MF 1,100 lT Visual No Preece et al (1998) 50-Hz MF 600 lT Visual No Crasson et al (1999) 50-Hz MF 100 lT Auditory No This study 50-Hz MF 20 lT Auditory and visual No 1994;Stevens 2001), further research with a wide spectrum of brain-function test batteries is desired.…”

Exposure to ELF magnetic and ELF‐modulated radiofrequency fields: The time course of physiological and cognitive effects observed in recent studies (2001–2005)

“…To the best of our knowledge, only Stevens [2001] has addressed how individual differences in responsivity to a MF may exist. He noted that subjects could be grouped based on their skin conductance responses (a measure of arousal) to a 50 Hz ELF MF, finding ''high,'' ''low,'' and ''no'' responders to the field.…”