Others also had reported an interaction between alcoholism and aging for the corpus callosum (Pfefferbaum et al 1996, 2002). There also was an interaction between aging and alcoholism with regard to brain tissue volumes, with volume abnormalities greater in older than younger alcoholics relative to age norms. Finally, in vivo MRI (Pfefferbaum et al 1996) and post-mortem studies (Harper and Kril 1990) have revealed significant callosal thinning in chronic alcoholics. In addition, in vivo studies based on diffusion tensor imaging have shown compromise of callosal fiber coherence in alcoholic men (Pfefferbaum et al 2000) and women (Pfefferbaum et al 2002), the extent of which relates to the degree of attentional and working memory deficits. One might speculate that thinning of the corpus collosum may render alcoholics less able to inhibit negative affect in right hemisphere circuits. Additionally, there is a growing literature on the relationship between handedness and abnormal hemispheric organization in alcoholics (eg, Ellis and Oscar-Berman 1989; Oscar-Berman and Schendan 2000; Sperling et al 2000). For example, Sperling and colleagues, in a study of 250 alcohol-dependent inpatients, found support for the hypothesis of deviant laterality in the presence of an elevated frequency of developmental risk factors. Type II alcoholic
