“[Professor Russell Poldrack] found that the information the distracted participants studied actually traveled to a different part of the brain than the information the other volunteers studied. Ideally, new information ought to go to the hippocampus, which has the capacity to store and recall information. In distracted volunteers, however, the hippocampus was not fully activated.”
http://www.nydailynews.com/lifestyle/health/2009/08/13/2009-08-13_
stop_the_multitasking_madness_attempting_to_do_it_all_can_cause_neurological_dam.html#discuss