Transcallosal transfer of information and functional asymmetry of the human brain

Abstract

The corpus callosum is the largest commissure in the brain and acts as a “bridge” of nerve fibres connecting the two cerebral hemispheres. It plays a crucial role in interhemispheric integration and is responsible for normal communication and cooperation between the two hemispheres. Evolutionary pressures guiding brain size are accompanied by reduced interhemispheric and enhanced intrahemispheric connectivity. Some lines of evidence suggest that the speed of transcallosal conduction is limited in large brains (e.g., in humans), thus favouring intrahemispheric processing and brain lateralisation. Patterns of directional symmetry/asymmetry of transcallosal transfer time may be related to the degree of brain lateralisation. Neural network modelling and electrophysiological studies on interhemispheric transmission provide data supporting this supposition.

Keywords:

• Lateralisation
• Interhemispheric transmission

Acknowledgements

This work was partially supported by the Polish Ministry of Science and Higher Education grant 0717/H03/2007/32 for scientific research in the years 2007–2010.