تکانشگری و آموزش معکوس در استفاده از الکل زیان آور

Research into the neuropsychological basis of impulsivity indicates that it may convey risk for substance misuse through an increased motivation to obtain rewards (“reward drive”) and a propensity to act without forethought (“rash impulsiveness”). A recent model of disinhibition has also specified a role for Neuroticism in those with left hemispheric preference, due to the association of this hemisphere with action goal tendencies. This study investigated the mediating role of reversal learning, a key component of adaptive decision-making, in the prediction of hazardous alcohol use from impulsivity traits. A sample of 165 college students were administered a probabilistic reversal learning task, the Alcohol Use Disorders Identification Test (AUDIT), Sensitivity to Reward scale to measure reward drive, I7 (Impulsiveness) to measure rash impulsiveness, Eysenck Personality Questionnaire – Revised, and a self-report measure of ear preference to determine hemispheric preference. Results support the role of reward drive and rash impulsiveness in alcohol misuse, as well as rash impulsiveness, Neuroticism and lateral preference in poor reversal learning. However, there was no support for mediation, or an interaction between Neuroticism and lateral preference.

Individuals high in impulsivity are at greater risk of developing substance use problems in the future (Tarter et al., 2003). However, impulsivity is not a unitary construct, and may comprise at least two distinct but overlapping constructs (Dawe and Loxton, 2004 and Whiteside and Lynam, 2001). The first reflects Sensitivity to Reward and approach motivation emerging from the mesolimbic dopamine system. Conceptually, it is closely related to Gray’s (1987) Behavioral Approach System (BAS) and the agency component of Extraversion (Depue & Collins, 1999). The second relates to difficulty inhibiting approach behavior in light of potential negative consequences, and is more related to orbitofrontal and cingulate serotonergic functioning (Gullo & Dawe, 2008). Conceptually, it resembles impulsiveness as defined by Eysenck and Eysenck (1991). Dawe and Loxton (2004) named these reward drive (RD) and rash impulsiveness (RI), respectively. Converging evidence suggests RD and RI are related to different aspects of substance misuse. Loxton et al. (2008) found that while club drug users were higher in RD and RI, only the latter was associated with polydrug use. Brunelle et al. (2004) reported scores on the Sensitivity to Reward scale (SR), a measure of RD, predicted reward-related physiological responses to alcohol intoxication, whereas RI did not. Consistent with this, Kambouropoulos and Staiger (2004) found cue-elicited urge to drink was related to SR scores, but not Sensation Seeking (RI-like trait) in social drinkers. In sum, there is empirical support for the utility of a two-factor approach to impulsivity and substance misuse. However, such a two-factor conceptualization may be limited by the focus on approach-related traits. Other models of impulsivity emphasize the contributing role of avoidance-based traits, and impulsivity that arises from a desire to reduce negative affect (Jackson, 2008 and Whiteside and Lynam, 2001). Jackson (2008) proposed that Neuroticism, a trait associated with increased arousability and negative affect (Eysenck, 1967), may interact with hemispheric asymmetry to produce disinhibited behavior. Notably, left prefrontal cortex activity has been associated with action goal formation and approach-related traits (Sutton & Davidson, 1997). Jackson (2008) provided evidence that individuals with right ear preference (a biomarker for left prefrontal asymmetry) were approach-oriented. Jackson then argued that people with left prefrontal asymmetry and high Neuroticism would be prone to heightened negative affect and would engage in impulsive behavior to reduce it. In four studies, Jackson demonstrated that the interaction between Neuroticism and right ear preference predicted various disinhibitory behaviors, including heavier alcohol use. Jackson’s proposition that Neuroticism interacts with approach motivation to predict disinhibition is also consistent with the work of Newman and colleagues (Patterson & Newman, 1993). Patterson and Newman (1993) proposed a mechanism in which individuals high in both Extraversion and Neuroticism were at greater risk of poor decision-making because of difficulty learning from errors. In summary, Jackson (2008) argues that ear preference may predict approach behavior directly and may interact with Neuroticism to predict disinhibited approach behavior. Others have argued that the “impulsivity” observed in addiction is primarily the result of disrupted decision-making (Bechara, 2005). Much of the research investigating decision-making in addiction has employed the Iowa Gambling Task (IGT; Bechara et al., 1994 and Bechara et al., 2001), which assesses adaptive, long-term decision-making. Briefly, the IGT requires participants to continuously draw from four decks of cards with different reward and punishment schedules. Two decks deliver high immediate gains but also higher delayed losses (disadvantageous decks), while the other two deliver low immediate gains but also lower delayed losses (advantageous decks). Most participants form an initial preference for the disadvantageous decks due to the high immediate rewards, but learn to shift to advantageous decks once losses begin to accrue (Fellows & Farah, 2005). However, substance dependent individuals and those with lesions to the orbitofrontal cortex (OFC) are less able to make this “preference shift” (Bechara et al., 2001). Non-substance dependent individuals high in RI-like traits also display difficulties on the IGT (Franken et al., 2008 and Zermatten et al., 2005). The role of the OFC in adaptive decision-making has led some to propose that poor decision-making is a key mechanism through which RI conveys risk for substance misuse (Dawe, Gullo, & Loxton, 2004). Indeed, several studies link RI with OFC functioning (Franken et al., 2008 and Horn et al., 2003). However, a recent prospective study on college students by Goudriaan, Grekin, and Sher (2007) found that while heavy binge drinkers performed worse on the IGT, this deficit was unrelated to RI. Indeed, other studies have also failed to find an association between RI-like traits and IGT performance (Franken & Muris, 2005). Such inconsistent findings may be due to the complexity of the IGT. The IGT engages several interdependent cognitive processes, but some argue that a deficit in reversal learning lies at the core of poor IGT performance (Fellows & Farah, 2005). Reversal learning is the updating of stimulus-reinforcement associations when contingencies change. Consistent with this view, Hildebrandt, Brokate, Fink, Muller, and Eling (2008) reported a selective deficit in reversal learning among young polysubstance abusers undergoing treatment. Similar findings were reported by Fellows and Farah (2005) in patients with OFC lesions, but not patients with lesions to other areas of the prefrontal cortex. Poor reversal learning may therefore be what mediates the risk conveyed by RI for problematic substance use. Consistent with this, Franken et al. (2008) found college students high in RI demonstrated poorer reversal learning. The aim of the present study was to examine the possible mediating role of reversal learning in the association between impulsivity and hazardous alcohol use. Poor reversal learning was hypothesized to mediate the effect of RI and the Neuroticism–ear preference interaction on hazardous drinking. Reward drive was hypothesized to directly predict more hazardous drinking. Moreover, RI, ear preference (as a main effect) and the Neuroticism–ear preference interaction were hypothesized to predict poorer reversal and more hazardous drinking.