Further to this issue:
There is an excellent review book on magnetic stimulation :
Chokroverty, S.(ed.) (1990) Magnetic Stimulation in Clinical Neurophysiology.
Boston: Butterworths Publ. ISBN: 0-409-90151-2
There are about half a dozen chapters on cortical stimulation via high
intensity magnetic fields, with some work on frontal area effects (limited
to frontal speech areas). I would guess that attempting to directly
stimulate the frontal lobes/poles would be likely to induce muscle activity
around the eyes and facial areas, let alone what activity might be induced
in the frontal cortex neurons. Also, some indication of the "non-muscular"
effects of magnetic stimulation are provided in a chapter by Amassian,
Maccabee, Cracco and Cracco. Occipital stimulation suppressed visual
perception of letter stimuli, with some selectivity over perception being
indicatedby changing the orientation of the stimulus pulse.
+----------------------------------------------------------------------------+
+ Dr. Paul Barrett CompuServe: 100157,140 +
+ University of Surrey, UK INTERNET: pss1pb at surrey.ac.uk +
+ Department of Psychology pbarrett at biosig.demon.co.uk +
+ Fax: (UK)-424-882417 Tel: (UK)-424-882410 +
+----------------------------------------------------------------------------+
