Differential ratings of pleasantness following right and left hemispheric application of low energy magnetic fields that stimulate long-term potentiation.

A total of 40 normal men and women were exposed under double blind conditions for 20 min to either sham-conditions or to 1 microT (10 mG) electromagnetic fields (known to produce long-term potentiation within hippocampal slices) that were applied primarily over the right temporal lobe, over the left temporal lobe or over both temporal lobes homogeneously. The men and women who received the stimulation over the right hemisphere rated their experiences as significantly more pleasant than those who received the same stimulation over the left hemisphere [eta = 0.51]. Covariance for the variation in ambient geomagnetic activity, which was negatively correlated with pleasantness, increased the significance of the experimental treatment. The potential clinical utility of applying computer-generated local and penetrative but weak intensity complex magnetic fields over portions of the human brain is discussed.