The current source estimation of the event related field derived from visual attention to the hemi-space

This study aimed to measure the event related field P2m using magnetoencephalogaphy (MEG), and to locate the equivalent current sources related to visual attention to the hemi-space. The current distributions were estimated from the P2m waveforms obtained from visual oddball paradigm tasks. The event related field P2m was observed around 200 msec after the onset of the target stimuli. Estimated sources from P2m were located on the both side of the occipto-temporal region and on the calcarine sulcus. The amplitude of the sources of the occipto-temporal region was different between the target condition and the control condition. A multiple dipole fitting indicated that the activity of the occipital cortex at P2m changed according to visual attention to the hemi-visual field.