The role of the corpus callosum (CC) in ensuring communication between the cerebral hemispheres is an undisputed great discovery of the 20th century. In the past 20 years, it has been repeatedly shown by behavioral and electrophysiological experiments that callosal transmission is asymmetric. It is faster from the right to the left hemispheres for a host of behavioral and cognitive processes. The functional meaning and the neural bases of the asymmetry are still being investigated but one possibility is that it is related to a larger proportion of cortical neurones, projecting their axon from the right to the left hemisphere than in the reverse direction in the CC. This asymmetry might be related to the necessity to rapidly access the left hemisphere for response during tasks mainly subserved by the right hemisphere. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.
Copyright © 2010 John Wiley & Sons, Ltd.