Olfactory potentials and olfactory magnetic fields evoked by odorant pulse stimuli

Presents noninvasive and objective measurements for the human olfactory sense and an estimation technique for the olfactory signal sources in the brain. In the experiments reported olfactory evoked potentials and olfactory magnetic fields using a 3ch DC-SQUID gradiometer were measured simultaneously. Odorant pulses were given into the nose cavity of a subject attached to a mask by a method which synchronized stimuli with the subject´s respiration. MEG response waves were measured on nearby forehead areas at the same latency time in coincidence with olfactory evoked potentials. These signal sources of the olfactory sense were estimated to exist in at least two areas of antidirectional dipoles near to the frontal lobe of the brain