Abstract
The corpus callosum, the principal neocortical commissure, allows for the inter- hemispheric transfer of lateralized information between the hemispheres. It is generally accepted that one of the principal functions of the callosum, at least in the visual and so- matosensory modalities, is to unite the sensory hemispaces for information projecting to different hemispheres (otherwise known as midline fusion). Two of the principal cues to sound localization in free-field are intensity and time differences for sound arriving to the two ears. Since each ear projects in a preponderant manner to the contralateral hemisphere and since complex sounds are generally analyzed at the cortical level, it is possible that the callosum is required to compare time and intensity differences for information arriving in a biased fashion to separate hemispheres. The aim of the present experiments was to examine this problem at the single cell level using cats and at the behavioral level with human subjects having cortical or callosal pathologies.
Two approaches were used to study how the callosum contributes to this type of binaural interaction: we recorded either callosal fibres directly (callosal efferent neurons) or cells in the callosal zone of A1 (callosal recipient neurons) in normal and callosotomized animals. The animals were anesthetized and recording was carried out in both cases under direct visual control. Stimuli were presented either dichotically through implanted earphones or on a frontally located sound perimeter. Tone bursts or white noise were presented to the two ears and intensity or time differences were varied. Results indicated that callosal efferent neurons or callosal recipient cells appear to prefer sounds coming mainly from the contralateral hemifield or at the midline. This was also confirmed with free-field stimulation. Removing this input through callosal section modifies the distribution of cells in A1 which are tuned to interaural intensity differences and somewhat less those sensitive to interaural time delays.
At the behavioral level, callosal agenesis or hemispherectomized subjects had to identify the apparent location of a sound presented on a frontally positioned perimeter surrounding the head on the horizontal meridian. Either a stationary sound or an apparently moving sound displaced at various velocities, length of trajectory and in the two directions were used. Results indicated, in accordance with the electrophysiological data, that localization performance was poorer in both groups of neurologically deficient subjects than in matched controls.
These results attest to the importance of the corpus callosum to localize sounds in free-field.
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References
Altman, J.A. (1968) Are there neurons detecting direction of sound source motion. Exp. Neurol. 22, 13–25.
Boudreau, J.C. and Tsuchitani, D. (1968) Binaural interaction in the cat superiror olive S segment. J. Neurophysiol. 31, 442–454.
Brugge, J. F., Anderson, DJ. and Aitkin, L.M. (1970) Responses of neurons in the dorsal nucleus of the lateral lemniscus of cat to binaural tonal stimulation. J. Neurophysiol. 33, 441–458.
Brugge. J.F., Dubrovsky, N.A., Aitkin, L.M. and Anderson, D.J. (1969) Sensitivity of single neurons in auditory cortex of cat to binaural tonal stiumlation: effects of varying interaural time and intensity. J. Neurophysiol. 32, 1005–1024.
Bryden, M.P., Ley, R.G. and Sugarman, J.H. (1985) Toward a model of dichotic listening performance. Brain and Cogn. 4, 241–257.
Duhamel J.-R., Pinek, B. and Brouchon, M. (1986) Manual pointing to auditory targets: performances of right versus left handed subjects. Cortex 22, 633–638.
Durlach, N.I. and Colburn, H.S. (1978) Binaural phenomena. In: E.C. Caterrette (Ed.), Handbook of Perception, Hearing, Vol. IV, Academic Press, New York, pp. 365–466.
Eisenman, L.M. (1974) An electrophysiological study in auditory cortex (Al) of the cat using free field stimuli. Brain Res. 75, 203–214.
Geshwind, N. (1972) Language and the brain. Scient. Am., 226, 76–83.
Hall, J.L. and Goldstein, M.H. (1968) Representation of binaural stimuli by single units in primary auditory cortex of unanesthetized cats. J. Acous. Soc. Am. 43, 456–461.
Hirsch, J.A., Chan, J.C. and Yin T.C. (1985) Responses of neurons in the cat’s superior colliculus to acoustic stim-uli. I. Monaural and binaural response properties. J. Neurophysiol. 53, 726–745.
Imig, T.J., Irons, W.A. and Samson, F.R. (1990) Single-unit selectivity to azimuthal direction and sound pressure level of noise burst in cat high-frequency primary auditory cortex. J. Neurophysiol. 63, 1448–1446.
Imig, T.J., Reale, R.A., Brugge, J.F., Morel, A. and Adrian, H.O. (1986). Topography of cortico-cortical connections related totonotopic and binaural maps of cat auditory cortex. In: F. Lepore, M. Ptitoand H.H. Jasper (Eds.), Two Hemispheres-One Brain: Functions of the Corpus Callosum, Alan R. Liss, New York, pp. 103–115.
Irvarsson, C, De Ribaupierre, Y. and De Ribaupierre, F. (1988) Influence of auditory localization cues on neuronal activity in the auditory thalamus of the cat. J. Neurophysiol. 59, 586–606.
Irvine, D.R. and Gago, G. (1990) Binaural interaction in high-frequency neurons in inferior colliculus of the cat: effects of variations in sound pressure level on sensitivity to interaural intensity differences. J. Neurophysiol. 63, 570–591.
Jenkins, W.M. and Masterton, R.B. (1982) Sound localization: Effects of unilateral lesions in central auditory system. J. Neurophysiol. 47, 987–1016.
Jenkins, W.M. and Merzenich, M.M. (1984) Role of cat primary auditory cortex for sound-localization behavior. J. Neurophysiol. 52, 819–847.
Kitzes, L.M., Wrege, K.S. and Cassady, J.M. (1980) Patterns of response of cortical cells to binaural stimulation. J. Comp. Neurol. 192, 455–472.
Klingon, G.H. and Bontecou, D.C. (1966) Localization in auditory space. Neurology 16, 879–886.
Kuwada. S., Yin, T.C. and Wickesberg, R.E. (1979) Response of cat inferior colliculus neurons to binaural beat stimuli: possible mechanisms for sound localization. Science 206, 586–588.
Makous, J.C. and Middlebrooks, J.C. (1990) Two-dimensional sound localization by human listeners. J. Acous. Soc. Am. 87, 2188–2200.
Middlebrooks, J.C, Dykes, R.W. and Merzenich, M.M. (1980) Binaural response-specific bands in primary audi-tory cortes (Al) of the cat: topographical organization orthogonal to iso-frequency contours. Brain Res. 181, 31–48.
Middlebrooks, J.C. and Pettigrew, J.D. (1981) Functional classes of neurons in primary auditory cortex of the cat distinguished by the sensibility to sound location. J. Neurosci. 1, 107–120.
Oldfield S.R. and Parker, S.P.A. (1984) Acuity of sound localization: A topography of auditory space. 1. Normal hearing conditions. Perception 13, 581–600.
Philipps, D.P. and Brugge, J.F. (1985) Progress of neurophysiology of sound localization. Ann. Rev. Psychol. 36, 245–274.
Philipps, D.P. and Irvine D.R.F. (1981) Response of single neurons in physiologically defined area Al of cat cerebral cortex: Sensitivity to interaural intensity differences. Hear. Res. 4, 299–307.
Poirier, P., Lepore, F., Provençal, C, Ptito, M. and Guillemot, J.-P. (1995) Binaural noise stimulation of auditory callosal fibers of the cat: response to interaural time delay. Exp. Brain Res., 104, 30–40.
Poirier, P., Samson, F.K. and Imig, T.J. (1996) Directional mechanisms and spatial preferences of single units in the cat’s inferior colliculus (IC). Neuroscience abst. 22, 889.
Rajan, R., Aitkin, L.M., Irvine D.R.F. and McKay, J. (1990) Azimuthal sensitivity of neurons in primary auditory cortex of cats 1. Types of sensitivity and the effects of variations in stimulus parameters. J. Neurophysiol. 64, 872–887.
Rauschecker, J.P. and Harris, L.R. (1989) Auditory and visual neurons in the cat’s superior colliculus selective for the direction of apparent motion stimuli. Brain Res. 490, 56–63.
Reale, R.A. and Kettner, R.E. (1986) Topography of binaural organization in primary auditory cortex of the cat: Effects of changing interaural intensity. J. Neurophysiol. 56, 663–682.
Samson, F.K., Clarey, J.C., Barone, P. and Imig, T.J. (1993) Effects of ear plugging on single-unit azimuth sensitivity in cat primary auditory cortex. 1. Evidence for monaural directional cues. J. Neurophysiol. 70, 492–511.
Samson, F.K., Poirier, P., Irons, W.A. and Imig, T.J. (1996) Effects of ear plugging on responses of azimuth-sensitive neurons in medial geniculate body (MGB) and primary auditory cortex (Al) of barbiturate-anesthetized cats. Neuroscience abst. 22, 889.
Sanchez-Longo, L.P. and Forster, F.M. (1958) Clinical significance of impairment of sound localization. Neurology 8, 119–125.
Sanchez-Longo, L.P, Forster, F.M. and Auth, T.L. (1957) A clinical test for sound localization and its applications. Neurology 7, 655–663.
Semple, M.N., Aitkin, L.M., Calford, M.B., Pettigrew, J.D. and Philipps., D.P. (1983). Spatial receptive fields in the cat inferior colliculus. Hear. Res. 10, 203–215.
Wise, L.Z. and Irvine, D.R. (1985) Topographic organization of interaural intensity difference sensitivity in deep layers of cat superior colliculus: implications for auditory spatial representation. J. Neurophyiol. 54, 185–211.
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Lepore, F., Poirier, P., Provençal, C., Lassonde, M., Miljours, S., Guillemot, JP. (1997). Cortical and Callosal Contribution to Sound Localization. In: Syka, J. (eds) Acoustical Signal Processing in the Central Auditory System. Springer, Boston, MA. https://doi.org/10.1007/978-1-4419-8712-9_35
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DOI: https://doi.org/10.1007/978-1-4419-8712-9_35
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