Differential activation of face memory encoding tasks in alcohol-dependent patients compared to healthy subjects: an fMRI study.

It has been hypothesized that the right hemisphere of the brain is more sensitive to alcohol-related damage than the left hemisphere. The present study tested this hypothesis, using functional MRI to determine whether the pattern for right hemispheric activity is different for alcohol-dependent patients, compared to normal healthy individuals. Two different types of memory encoding tasks were performed separately: word and face encoding for both alcohol-dependent patients and normal healthy volunteers. The data for the normal volunteers indicate that the left prefrontal region is more active during word encoding, whereas the right parahippocampal region is more active during face encoding. The results for the patient data, however, demonstrated left lateralization in the prefrontal area during word encoding, while right lateralization in the parahippocampal region during face encoding was not observed. Therefore, alcoholism appears to have no influence on left hemispheric activity, since the activation pattern was similar to that observed for normal healthy persons. However, the absence of right hemispheric lateralization in alcohol-dependent patients is consistent with the hypothesis that the right hemisphere is more vulnerable to alcohol-related damage than the left hemisphere.