However, it should also be mentioned that correlations between ERO theta power and BIS impulsivity scores were not significant, although such a relationship has been well established in alcoholic subjects [49]. This suggests that neural mechanisms (or circuits) underlying reward processing on the one hand, and that of impulsivity on the other hand, may each be separately related (“parallel connections”) to risk status without influencing each other at relatively younger ages (HR sample) than in older age groups (alcoholic sample). Another possibility is that only those with significant correlations between (and thereby interaction across) these two systems related to reward theta EROs and impulsivity may develop alcohol dependence, although we do not have any evidence in the current study to support this assertion. In a previous study in alcoholics, we found a significant correlation between theta ERO during reward processing and impulsivity (BIS) [49]. This lack of correlation between theta ERO and impulsivity in the current study may be attributable to the differences in brain maturation and reward processing mechanisms between adult alcoholics and the relatively younger HR subjects [181,182].
