n.
or hemispheric asymmetry
Characteristic of the human brain in which certain functions (such as language comprehension) are localized on one side in preference to the other.
One example is handedness (the tendency to use one hand or the other to perform activities): Since the left and right cerebral hemispheres control the right and left sides of the body, respectively, right-handed people are typically left-dominant in terms of hemispheric control of various motor functions and also with respect to seeing (right-eyed) and language comprehension. Paul Broca first identified the brain centre for articulate speech in what is now called Broca's area. Later researchers discovered that functions involving logical or sequential analysis generally reside in the left hemisphere, while the right hemisphere seems to control processing of spatio-visual information and musical relations. More left-handers than right-handers display a reversal of hemispheric specialization or a more even distribution of functions between the two hemispheres. There is no general agreement about whether laterality is genetically transmitted, developed during gestation, or learned.