Differences in both P3 amplitude and CSD topography were also reported in visual oddball tasks in alcoholics (Rodriguez Holguin et al., 1999a; Cohen et al., 2002) as well as in their high risk offspring (Rodriguez Holguin et al., 1999b), although the group differences were topographically different in the visual task compared to the auditory mode. For example, Cohen et al. (2002) reported a modality-specific pattern in that alcoholics manifested weaker P3 sources mainly over the frontal region in the auditory modality and primarily over the parietal-occipital region in the visual modality.
