Abstract
During cognitive tasks, the cerebral hemispheres cooperate, compete, and in general, interact via the corpus callosum. Although behavioral studies in normal and split-brain subjects have revealed a great deal about the transcallosal exchange of information, a fundamental question remains unanswered and controversial: Are transcallosal interhemispheric influences primarily excitatory or inhibitory? In this context, we examined the effects of simulating sectioning of the corpus callosum in a computational model of visual letter recognition. Differences were found, following simulated callosal sectioning, in the performance of each individual hemisphere, in the mean activation levels of hemispheres, and in the specific patterns of activity, depending on the nature of the callosal influences. Together with other recent computational modeling results, the findings are most consistent with the hypothesis that transcallosal influences are predominantly excitatory, and they suggest measures that could be examined in future experimental studies to help resolve this issue.
Article PDF
Similar content being viewed by others
References
Andrews, R. J., Bringas, J. R., Alonzo, G., Khoshyomn, S., & Gluck, D. S. (1993). Corpus callosotomy effects on cerebral blood flow and evoked potentials (transcallosal diaschisis). Neuroscience Letters, 154, 9–12.
Appell, P. P., & Behan, M. (1990). Sources of subcortical GABAergic projections to the superior colliculus in the cat. Journal of Comparative Neurology, 302, 143–158.
Berlucchi, G. (1983). Two hemispheres but one brain. Behavioral & Brain Sciences, 6, 171–173.
Berlucchi, G., Aglioti, S., & Tassinari, G. (1997). Rightward attentional bias and left hemisphere dominance in a cue-target light detection task in a callosotomy patient. Neuropsychologia, 35, 941–952.
Bogen, J. E., Fisher, E. D., & Vogel, P. J. (1965). Cerebral commissurotomy: A second case report. Journal of the American Medical Association, 194, 1328–1329.
Cappa, S. F., Perani, D., Grassi, F., Bressi, S., Alberoni, M., Franceschi, M., Bettinardi, V., Todde, S., & Fazio, F. (1997). A PET follow-up study of recovery after stroke in acute aphasics. Brain & Language, 56, 55–67.
Caselli, R. J. (1991). Bilateral impairment of somesthetically-mediated object recognition in humans. Mayo Clinic Proceedings, 66, 357–364.
Cook, N. D. (1986). The brain code: Mechanisms of information transfer and the role of the corpus callosum. London: Methuen.
Cook N. D. (1999). Simulating consciousness in a bilateral neural network: “Nuclear” and “fringe” awareness. Consciousness & Cognition, 8, 62–93.
Cook, N. D., & Beech, A. R. (1990). The cerebral hemispheres and bilateral neural nets. International Journal of Neuroscience, 52, 201–210.
Corballis, M. C. (1991). The lopsided ape: Evolution of the generative mind. New York: Oxford University Press.
Cummings J. (1985). Hemispheric asymmetry in visual-perceptual and visual spatial function. In D. F. Benson & E. Zaidel (Eds.), The dual brain: Hemispheric specialization in humans (pp. 233–246). New York: Guilford.
Davidson, R. J., & Hugdahl, K. (1995). Brain asymmetry. Cambridge, MA: MIT Press.
Denenberg, V. (1983). Micro and macro theories of the brain. Behavioral & Brain Sciences, 6, 174–178.
Dobkin, J. A., Levine, R. L., Lagreze, H. L., Dulli, D. A., Nickles, R. J., & Rowe, B. R. (1989). Evidence for transhemispheric diaschisis in unilateral stroke. Archives of Neurology, 46, 1333–1336.
Ferbert, A., Priori, A., Rothwell, J. C., Day, B. L., Colebatch, J. G., & Marsden, C. D. (1992). Interhemispheric inhibition of the human motor cortex. Journal of Physiology, 453, 525–546.
Fink, G. R., Driver, J., Rorden, C., Baldeweg, T., & Dolan, R. J. (2000). Neural consequences of competing stimuli in both visual hemifields: A physiological basis for visual extinction. Annals of Neurology, 47, 440–446.
Fiorelli, M., Blin, J., Backchine, S., Laplane, D., & Baron, J. C. (1991). PET studies of cortical diaschisis in patients with motor hemi-neglect. Journal of Neurological Science, 104, 135–142.
Galuske, R. A., Schlote, W., Bratzke, H., & Singer, W. (2000). Interhemispheric asymmetries of the modular structure in human temporal cortex. Science, 289, 1946–1949.
Gazzaniga, M. S. (1995). Principles of human brain organization derived from split-brain studies. Neuron, 14, 217–228.
Geschwind, N., & Levitsky, W. (1968). Human brain: Left-right asymmetries in temporal speech region. Science, 161, 186–187.
Goroud, M., & Dumas, R. (1995). Clinical and topographical range of callosal infarction: A clinical and radiological correlation study. Journal of Neurology, Neurosurgery, & Psychiatry, 59, 238–242.
Hellige, J. B. (1993). Hemispheric asymmetry: What’s right and what’s left. Cambridge, MA: Harvard University Press.
Hellige, J. B., Cowin, E., & Eng, T. (1995). Recognition of CVC syllables from LVF, RVF and central location. Journal of Cognitive Neuroscience, 7, 258–266.
Hellige, J. B., & Webster, R. (1979). Right hemisphere superiority for initial stages of letter processing. Neurophysiologia, 17, 653–660.
Hilgetag, C., Kotter, R., & Young, M. (1999). Inter-hemispheric competition of subcortical structures is a crucial mechanism in paradoxical lesion effects and spatial neglect. In J. A. Reggia, E. Ruppin, & D. Glanzman (Eds.), Disorders of brain, behavior and cognition: The neurocomputational perspective (pp. 121–144). Amsterdam: Elsevier.
Hughes, C. M., & Peters, A. (1992). Symmetric synapses formed by callosal afferents in rat visual cortex. Brain Research, 583, 271–278.
Innocenti, G. (1986). General organization of callosal connections in the cerebral cortex. In E. Jones & A. Peters (Eds.), Cerebral cortex (Vol. 5, pp. 291–353). New York: Plenum.
Jacobs, R., & Kosslyn, S. (1994). Encoding shape and spatial relations. Cognitive Science, 18, 361–386.
Lassonde, M. (1986). The facilitatory influence of the corpus callosum on intrahemispheric processing. In F. Leporé, M. Pitto, & H. H. Jasper (Eds.), Two hemispheres, one brain: Functions of the corpus callosum (pp. 385–401). New York: Liss.
Levitan, S., & Reggia, J. A. (1999). Interhemispheric effects on map organization following simulated cortical lesions. Artificial Intelligence in Medicine, 17, 59–85.
Levitan, S., & Reggia, J. A. (2000). A computational model of lateralization and asymmetries in cortical maps. Neural Computation, 12, 2037–2062.
Levy, J., Trevarthen, C., & Sperry, R. W. (1972). Reception of bilateral chimeric figures following hemispheric deconnexion. Brain, 95, 61–78.
Macdonell, R. A., Shapiro, B. E., Chiappa, K. H., Helmers, S. L., Cros, D., & Day, B. J. (1991). Hemispheric threshold differences for motor evoked potentials produced by magnetic coil stimulation. Neurology, 41, 1441–1444.
Mangun, G., Hillyard, S., Luck, S., Handy, T., Plager, R., Clark, V., Loftus, W., & Gazzaniga, M. (1994). Monitoring the visual world: Hemispheric asymmetries and subcortical processes in attention. Journal of Cognitive Neuroscience, 6, 267–275.
Meyer, B. U., Roricht, S., Grafin von Einsiedel, H., Kruggel, F., & Weindl, A. (1995). Inhibitory and excitatory interhemispheric transfers between motor cortical areas in normal humans and patients with abnormalities of the corpus callosum. Brain, 118, 429–440.
Meyer, B. U., Roricht, S., & Woiciechowsky, C. (1998). Topography of fibers in the human corpus callosum mediating interhemispheric inhibition between the motor cortices. Annals of Neurology it, 43, 360–369.
Meyer, J. S., Obara, K., & Muramatsu, K. (1993). Diaschisis. Neurological Research, 15, 362–366.
Mountcastle, V. B. (1998). Perceptual neuroscience: The cerebral cortex. Cambridge, MA: Harvard University Press.
Netz, J., Ziemann, U., & Homberg, V. (1995). Hemispheric asymmetry of transcallosal inhibition in man. Experimental Brain Research, 104, 527–533.
Pascual-Leone, A., Wasserman, E. M., Sadato, N., & Hallett, M. (1995). The role of reading activity on the modulation of motor cortical outputs to the reading hand in braille readers. Annals of Neurology, 38, 910–915.
Popper, A. N., & Fay, R. R. (Eds.) (1992). The mammalian auditory pathway: Neurophysiology. New York: Springer-Verlag.
Reggia, J. A., Gittens, S. D., & Chhabra, J. (2000). Post-lesion lateralisation shifts in a computational model of single-word reading. Laterality, 5, 133–154.
Reggia, J. A., Goodall, S. M., & Levitan, S. (2001). Cortical map asymmetries in the context of transcallosal excitatory influences. NeuroReport, 12, 1609–1614.
Reggia, J. A., Goodall, S. M., & Shkuro, Y. (1998). Computational studies of lateralization of phoneme sequence generation. Neural Computation, 10, 1277–1297.
Reggia, J. A., Goodall, S. M., Shkuro, Y., & Glezer, M. (2001). The callosal dilemma: Explaining diaschisis in the context of hemispheric rivalry via a neural network model. Neurological Research, 23, 465–471.
Ringo, J. L., Doty, R. W., Demeter, S., & Simard, P. Y. (1994). Time is of the essence: A conjecture that hemispheric specialization arises from interhemispheric conduction delay. Cerebral Cortex, 4, 331–343.
Rizzo, M., & Robin, D. A. (1996). Bilateral effect of unilateral visual cortex lesions in human. Brain, 119, 951–963.
Scheibel, A., Fried, I., Paul, L., Forsythe, A., Tomiyasu, U., Wechsler, A., Kao, A., & Slotnick, J. (1985). Differentiality characteristics of the human speech cortex: A quantitative golgi study. In D. F. Benson & E. Zaidel (Eds.), The dual brain: Hemispheric specialization in humans (pp. 65–74). New York: Guilford.
Seymour, S. E., Reuter-Lorenz, P. A., & Gazzaniga, M. S. (1994). The disconnection syndrome: Basic finding reaffirmed. Brain, 117, 104–115.
Shevtsova, N., & Reggia, J. A. (1999). A neural network model of lateralization during letter identification. Journal of Cognitive Neuroscience, 11, 167–181.
Shevtsova, N., & Reggia, J. A. (2000). Interhemispheric effects of simulated lesions in a neural model of letter identification. Brain & Cognition, 44, 557–603.
Shkuro, Y., Glezer, M., & Reggia, J. A. (2000). Interhemispheric effects of simulated lesions in a neural model of single-word reading. Brain & Language, 72, 343–374.
Stemmler, M., Usher, M., & Niebur, E. (1995). Lateral interactions in primary visual cortex: A model bridging physiology and psychophysics. Science, 269, 1877–1880.
Toyama, K., Tokashiki, S., & Matsunami, K. (1969). Synaptic action of commissural impulses upon association efferent cells in cat visual cortex. Brain Research, 14, 518–520.
Tucker, D. M., & Williamson, P. A. (1984). Asymmetric neural control systems in human self-regulation. Psychological Review, 91, 185–215.
Yamaguchi, T., Kunimoto, M., Pappata, S., Chavoix, C., Brouillet, E., Riche, D., Maziere, M., Naguet, R., Mackenzie, E. T., & Baron, J. C. (1990). Effects of anterior corpus callosum section on cortical glucose utilization in baboons. Brain, 113, 937–951.
Zaidel, E. (1995). Interhemispheric transfer in the split brain. In R. J. Davidson & K. Hugdahl (Eds.), Brain asymmetry (pp. 491–532). Cambridge, MA: MIT Press.
Author information
Authors and Affiliations
Corresponding author
Additional information
This work was supported by NINDS Award NS35460.
Rights and permissions
About this article
Cite this article
Shevtsova, N., Reggia, J.A. Effects of callosal lesions in a model of letter perception. Cognitive, Affective, & Behavioral Neuroscience 2, 37–51 (2002). https://doi.org/10.3758/CABN.2.1.37
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.3758/CABN.2.1.37