Impulsive Errors on a Go-NoGo Reaction Time Task: Disinhibitory Traits in Relation to a Family History of Alcoholism

The 12-Month Prevalence of DSM-IV alcohol abuse and dependence in the United States was 8.46% in 2001 to 2002, affecting approximately 17.6 million people (Grant et al., 2004). White males, 18 to 44 years of age, was the largest affected group, with prevalence rates approximately twice those of same-age white females (Grant et al., 2004). Alcohol contributes to 25% of accidental deaths (Sutocky et al., 1993) making it desirable to identify characteristics that predispose individuals toward alcohol problems. Twin-adoption studies provide evidence of a genetic risk for alcoholism (Cloninger et al., 1981), and a positive family history (FH+) predicts problem drinking patterns and 2 to 4 times the risk for future alcoholism (Lieb et al., 2002; Merikangas et al., 1998). In order to examine premorbid factors unconfounded by consequences of heavy drinking, we established the Oklahoma Family Health Patterns project (OFHP), a long-term study designed to provide a broad base of information on psychological, behavioral, and physiological response characteristics in healthy, young-adult, offspring of alcoholic parents. In this paper, we examine behavioral impulsivity as manifested by rates of false alarms in a Go-NoGo psychomotor task. Impulsivity and disinhibitory tendencies may be closely associated with risk for alcoholism. Cloninger and colleagues have shown that FH+ children who later developed drinking problems had premorbid signs of behavioral disinhibition, seen as low harm avoidance along with novelty seeking and impulsivity (Cloninger, 1987). Likewise, Sher and colleagues reported that healthy, FH+ college students exhibited impulsiveness, aggressiveness, and sensation seeking, a pattern that they termed “behavioral under-control” (Sher, 1991). Tarter and colleagues described adolescent male offspring of substance abusing fathers, as exhibiting a pattern of “neurobehavioral disinhibition” and psychological dysregulation (Tarter, 2002; Tarter et al., 1985). These terms characterize externalizing tendencies that appear with greater frequency in FH+ than in FH–and which could represent a core, inherited behavioral disposition associated with vulnerability to future alcoholism (Krueger et al., 2002). Among externalizing traits, impulsivity underlies poor planning and unreflective, reckless, abrupt, and inappropriate behaviors that may lead to negative outcomes (Finn et al., 1999). Temperament characteristics of subjects in the OFHP cohort suggest a differential clustering of externalizing tendencies in FH+ persons; the FH+ have scored consistently lower than the FH– on the Sociability Scale of the California Psychological Inventory (CPI-So) (Gough, 1994). Low scores on this scale (<30) suggest a tendency toward norm violation, impulsive decision-making, and lack of guilt for social offenses. In the present sample, 46% of FH+ subjects score <30 versus only 19% of the FH− do so, a differential proportion of nearly 2.5 (Table 1). The present study was done to determine the extent to which low CPI-So scores are associated with a behavioral manifestation of impulsivity. Table 1 Sample Characteristics We used a Go-NoGo reaction time task to test behavioral impulsivity. Finn found that alcohol exposure increased Go-NoGo false alarm rates in young adults with low working memory capacity, a presumed risk for alcoholism, although FH groups did not differ (Finn et al., 1999). False alarm rates were similarly higher in early-onset alcoholics with conduct disorder and low working memory capacity (Finn et al., 2002), indicating that impulsivity is associated with a common risk factor for alcoholism (conduct disorder) and with reduced ability for self-monitoring and behavioral self-regulation (low working memory capacity). Versions of the Go-NoGo task have also been found sensitive to impulsive traits in cigarette smokers (Mitchell, 2004), alcoholics with Axis II, Cluster B disorders (Dom et al., 2006), and in cocaine abusers (Verdejo-Garcia et al., 2007). The Go-NoGo task is a forced-choice reaction time task that demands rapid responses on Go signals and nonresponses on NoGo signals administered in a state of uncertainty, making it ideal to assess behavioral impulsivity (Mitchell, 2004). Signal Detection theory provides a framework within which to measure, analyze, and interpret the decision-making processes in the Go-NoGo task (Kornbrot, 2006). Neuroimaging studies supplement this behavioral evidence, providing insights into neuroanatomical regions associated with the decision-making process (Amodio and Frith, 2006). Our finding that FH+ have much lower CPI-So scores than FH− suggests a greater tendency toward behavioral impulsivity and norm violation in this group. The greater prevalence of externalizing disorders in males compared to females suggests that these tendencies should be more pronounced in the male FH+ subgroup. Accordingly, we predicted that false alarm rate, a measure sensitive to impulsive responding in the Go-NoGo task, would be higher in FH+ relative to FH−, in those with lower CPI-So scores, and in males.