Hemispheric differences in the auditory evoked response

doi:10.1016/0013-4694(77)90200-0

Electroencephalography and Clinical Neurophysiology

Volume 43, Issue 1, July 1977, Pages 99-102

https://doi.org/10.1016/0013-4694(77)90200-0 Get rights and content

Abstract

The separation of the 80–250 msec portion of the AER to click stimulation into N₁P₂, produced by large areas of cortex, and the T complex, probably produced by secondary auditory cortex, was recently described (Wolpaw and Penry 1975). The present study investigated the ipsilateral vs. contralateral and right vs. left hemispheric differences in N₁P₂ and T complex latencies and amplitudes. One msec clicks at 60 dB above threshold were presented at 4.7 sec intervals monaurrally to 32 normal adults and binaurally to 13 of the 32. AERs were recorded from vertex and temporal referred to a balanced non-cephalic reference electrode.

For monaural stimulation, N₁P₂ and T complex amplitudes were significantly greater and T complex latency was significantly less over the contralateral and right hemispheres. The ipsilateral vs. contralateral and right vs. left hemispheric amplitude differences were significantly greater for the T complex than for N₁P₂. Binaural results, which provided in additional measure of right vs. left hemispheric differences, were in agreement with the monaural findings. The results are consistent with neurophysiologic and behavioral findings in regard to ipsilateral vs. contralateral and right vs. left hemispheric differences and support the hypothesis that the T complex is produced by secondary auditory cortex.

Résumé

Dans un travail récent (Wolpaw et Penry 1975) une distinction a été établie dans la portion de la réponse évoquée auditive (CAER) à une stimulation par clicks située entre 80 et 250 msec entre l'ensemble N₁P₂, enregistré sur une vaste surface du cortex, et le complexe T en provenance du cortex auditif secondaire. Le travail actuel rapporte les résultats des études de différence de latence et d'amplitude de N₁P₂ et du complexe T entre les hémisphères droit et gauche, ainsi qu'entre les hémisphères ipsi et contro-latéraux. Des clicks de 1 msec, de 60 dB au-dessus du seuil, sont présentés à des intervalles de 4 à 7 secondes de façon monaurale à 32 adultes normaux et de façon binaurale à 13 d'entre eux. Les AERs sont enregistrés au niveau du cortex et des régions temporales connectés à une électrode de réfe̊nce non céphalique équilibrée. Pour la stimulation monaurale, les amplitudes de N₁P₂ et du complexe T sont significativement plus grandes et la latence du complexe T est significativement moindre sur l'hémisphère controlatéral et sur l'hémisphère droit. Les différences d'amplitude de l'hémisphère ipsilatéral vs contralatéral et de l'hémisphère droit vs gauche sont sifnificativement plus grandes pour le complexe T que pour N₁ P₂. Les résultats des stimulations binaurales qui fournissent une mesure additionnelle des différences hémispères droit vs gauche sont en accord avec les données monaurales. Ces résultats confirmement les données neurophysiologiques comportementales concernant les différences entre les hémisphères, ipsilatéral vs controlatéral et droit vs gauche et sont en faveur de l'hypothèse suivant laquelle le complexe T provient du cortex auditif secondaire.

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Hemispheric differences in the auditory evoked responseDifférences interhémisphèriques de la réponse évoquée auditive

Abstract

Résumé

Neuropsychologia

Cortex

Cortex

Cortex

Brain Res.

Electroencephalogr. clin. Neurophysiol.

Electroencephalogr. clin. Neurophysiol.

Exp. Neurol.

Neuropsychologia

Electroencephalogr. clin. Neurophysiol.

The central auditory pathway

J. Neurophysiol.

Activity of neural units in medial geniculate body of cat and rabbit

J. Neurophysiol.

Memory and growth in the superior temporal gyri

Canad. J. Neurol. Sci.