The study investigated directional differences in interhemispheric tra
nsmission time using the VEPs method. Specificially we were interested
in whether there exists an asymmetry in the transmission of informati
on to and from the hemisphere specialized in its processing. Two type
of stimuli, specific for the left and right hemisphere, were presented
in the left and right visual fields. The latency differences between
visual evoked potential components registered in the hemispheres ipsil
ateral and contralateral to the stimulated hemifield were compared. In
terhemispheric transmission time was shorter when the information was
transferred from the hemisphere non-specialized for its processing to
the specialized one than in the opposite direction. The results sugges
t the existence of a physiological mechanism that ensures fast transmi
ssion of information to that hemisphere which is more efficient in its
processing.