Ear dominance and laterality of cortical activation identified by event-related desynchronization mapping

Lateralized cortical functioning was assumed to be involved in ear dominance for pitch information. Left ear dominant (LED), right ear dominant (RED) subjects and individuals with no distinct ear preference (NED) were examined by means of the event-related desynchronization-mapping method during stimulation with a dichotic listening test. Contrary to expectations ED-groups did not systematically show greater involvement of the hemisphere contralateral to the dominant ear. RED were characterized by a response-dependent cortical activation pattern, LED exhibited a marked ipsilateral desynchronization focus if they showed preference for the dominant ear. In the NED group an early asymmetrical activation distribution was observed during the perception interval, which was concentrated ipsilaterally to the preferred ear.