FUNCTIONAL ASYMMETRIES OF CROSSED AND UNCROSSED MEDIAL OLIVOCOCHLEAR EFFERENT PATHWAYS IN HUMANS

In a previous study, a peripheral auditory asymmetry in right-handers was found. The activity of the uncrossed medial olivocochlear efferent pathway has been shown to be more effective in the right than in the left ear. Our aim was to compare right and left medial olivocochlear i nhibition during contralateral, ipsilateral and binaural ear stimulati on with a broad band noise, in order to better localize this asymmetry . Uncrossed pathway asymmetry was confirmed and the crossed pathway sh owed a reverse asymmetry: a left ear advantage. These results are in a ccordance with the assumption that the medial superior olivary complex is the locus of the asymmetry observed, As this nuclear complex recei ves central efferents, the peripheral auditory asymmetry may be relate d to the well-known cortical asymmetry. (C) 1998 Elsevier Science Irel and Ltd. All rights reserved.