Abstract: This investigation is part of a more general study of binaural perception and
its electrophysiological correlates. In order to account for some of the
phenomena of binaural perception, Boring (I) proposed that the two ears
are represented at the auditory cortex by two different populations of cortical units.
We have attempted to test this hypothesis, taking up two aspects in succession:
I) Do the populations of cortical units that represent the two ears differ in
size at the two cerebral hemispheres?S timulation of either ear evokes electrophysiological
responseso ver the entire extent of the auditory cortex of both hemispheres.
It has been suggestedt hat the responsesa re larger in amplitude at the hemisphere
contralateral to the ear stimulated (2-4), but this has also been denied (5). We will
present quantitative evidence to show that at both hemispheres the response of
the contralateral ear is significantly larger than the response of the ipsilateral ear.3
2> Are the two ears represented by independent populations of cortical units,
or are they represented by overlapping populations of cortical units? Results from
a small number of experiments indicate that the two populations overlap considerably.