Source localization of middle latency auditory evoked responses using MEG and MRI techniques

A combination of magnetoencephalography (MEG) and MRI was used to localize the sources of human middle latency auditory evoked responses (MLR). MEG measurements were performed over the right hemisphere of five normal volunteers while the left ear was stimulated by clicks. The MEG data were plotted onto the individual MR images. The sources of Pa, Nb, and Pb responses, which are the main components of MLR, were estimated to be in the auditory cortex. The source of Nb was found to be lateral to the source of Pa. In addition, the source of Pb was estimated to be anterior and lateral to the source of Pa