Evidence for cortical origin of the 40 Hz auditory evoked response in man.

We have recorded cerebral magnetic fields to trains of 40 Hz clicks in 6 subjects to study the neural generators of the 40 Hz auditory evoked response (AER). The largest deflection, N100m (magnetic counterpart of the electric N100), was preceded by a low voltage P40m and followed by P200m. A sustained field, SF, was seen at 300-500 msec. A rhythmic 40 Hz… (More)