Current research supports that the two hemispheres each perform a number of separate roles while also communicating with one another via the corpus callosum. What’s more, the side of the brain used for these roles is not the same for every person, as it can be influenced by whether he or she is left- or right-handed. However, that doesn’t support the theory of a dominant side. An individual’s brain activity also differs, depending on what task is being performed. In fact, certain activities have been found to activate and “exercise” the sides separately, while others exercise both at the same time.
