Predictors of Effective Working Memory Training in Individuals with Alcohol Use Disorders.

BACKGROUND: Low working memory (WM) capacity is associated with alcohol use disorders (AUDs). The importance of WM to adaptive functioning has led to a recent influx of studies attempting to improve individual WM capacity using various cognitive training methods. The present study aimed to examine the efficacy of complex WM training for improving WM capacity among individuals with AUD. METHODS: Individuals were randomized to complete either adaptive WM training or active control training. We applied a methodologically rigorous and structured approach, including a battery of near and moderate transfer measures in those with AUDs and a control group. Additionally, we examined cognitive factors (at baseline) and other predictors of adherence, training task improvement, and transfer. RESULTS: Results suggest improved WM in individuals with AUDs and controls, as evidenced by improved scores on several transfer measures, after adaptive WM training. However, individuals with AUDs showed poorer adherence and less improvement on the training tasks themselves. Neither IQ, WM, sex, nor condition predicted adherence. Level of training task performance, baseline WM, and IQ predicted transfer task improvement. CONCLUSIONS: This is the first study to rigorously examine both the efficacy of WM training in those with AUDs, and predictors of successful training program adherence and transfer in a large sample. Among study completers, results suggest that AUD status does not predict training improvement and transfer. However, AUD status did predict lower program adherence. WM training was more effective in those with higher cognitive ability at baseline. This study provides direct translation to the development of cognitive interventions for treating AUD.

The effects of working memory load and attention refocusing on delay discounting rates in alcohol use disorder with comorbid antisocial personality disorder.

Executive working memory capacity (eWMC) is central to adaptive decision-making. Research has revealed reduced eWMC and higher rates of impulsive decision making in individuals with alcohol use disorders (AUDs: DSM-IV Alcohol Dependence of Alcohol Abuse) and antisocial psychopathology (AP). Recent work has shown that placing a load on working memory (WM) further increases impulsive decision making on the delay discounting (DD) task in those with AUDs and AP. The current study examined the effects of an attention refocusing manipulation to offset the effects of this WM-load on DD rates in control subjects, those with AUDs without AP, and AUDs with AP (AUD-AP). Results revealed that 1) the AUD-AP group had higher DD rates (i.e., more impulsive decision-making) than the AUD group, followed by controls, and 2) attention refocusing after a load is placed on WM was associated with lower DD rates compared to the load without refocusing in both AUD groups, but not controls. Results suggest that refocusing attention after a cognitive load may be an effective cognitive strategy for reducing the impulsivity-enhancing effects of cognitive load on decision making in individuals with AUDs and AP.

Delay Discounting of Losses in Alcohol Use Disorders and Antisocial Psychopathology: Effects of a Working Memory Load.

BACKGROUND: Alcohol use disorders (AUDs) are associated with increased discounting of delayed rewards and reduced executive working memory (eWM) capacity. This association is amplified when comorbid with antisocial psychopathology (AP). Furthermore, recent studies suggest that reduced WM capacity is associated with disinhibited decisions reflected by increased impulsive decision making on the delay discounting of rewards task. While discounting of delayed rewards is well studied, the discounting of delayed losses has received significantly less experimental attention. METHODS: The current study investigated (i) the rate of discounting of delayed losses in individuals with AUD only (n = 61), AUD with comorbid AP (n = 79) and healthy controls (n = 64); (ii) the relationship between eWM capacity and discounting of delayed losses; and (iii) the effect of a WM load on discounting of delayed losses. Discounting performance was assessed using a computerized discounting of delayed losses task. RESULTS: Results showed that the AUD-only and AUD-AP groups had higher rates of discounting of delayed losses and lower eWM capacity compared to the control groups. Lower individual eWM capacity was associated with increased discounting of delayed losses. However, WM load did not increase discounting rates overall. CONCLUSIONS: These results support the hypothesis that greater discounting of delayed losses is associated with AUD and comorbid AP problems and lower individual eWM capacity.

A random utility model of delay discounting and its application to people with externalizing psychopathology.

Previous studies have demonstrated that working memory capacity plays a central role in delay discounting in people with externalizing psychopathology. These studies used a hyperbolic discounting model, and its single parameter-a measure of delay discounting-was estimated using the standard method of searching for indifference points between intertemporal options. However, there are several problems with this approach. First, the deterministic perspective on delay discounting underlying the indifference point method might be inappropriate. Second, the estimation procedure using the R2 measure often leads to poor model fit. Third, when parameters are estimated using indifference points only, much of the information collected in a delay discounting decision task is wasted. To overcome these problems, this article proposes a random utility model of delay discounting. The proposed model has 2 parameters, 1 for delay discounting and 1 for choice variability. It was fit to choice data obtained from a recently published data set using both maximum-likelihood and Bayesian parameter estimation. As in previous studies, the delay discounting parameter was significantly associated with both externalizing problems and working memory capacity. Furthermore, choice variability was also found to be significantly associated with both variables. This finding suggests that randomness in decisions may be a mechanism by which externalizing problems and low working memory capacity are associated with poor decision making. The random utility model thus has the advantage of disclosing the role of choice variability, which had been masked by the traditional deterministic model. (PsycINFO Database Record

The Effects of a Working Memory Load on Delay Discounting in Those with Externalizing Psychopathology.

This study investigated the influence of executive working memory (EWM) capacity on impulsive decision-making in a sample of young adults (n=623) that varied in degree of externalizing psychopathology (EXT) by examining: (i) the effects of WM load on delay discounting rates, and, (ii) the association between EWM capacity and delay discounting rates. EXT was measured as a latent variable indicated by lifetime problems with alcohol, marijuana, other drugs, childhood conduct, and adult antisocial behavior. Results showed that (i) the WM load increased discounting rates throughout the spectrum of EXT, (ii) EXT was associated with higher discounting rates and lower EMW capacity, and (iii) WM capacity was significantly associated with higher discounting rates when controlling for IQ, but only after a WM load. The results are discussed in terms of the role of EWM capacity in impulsive decision making in EXT.

Effects of working memory load, a history of conduct disorder, and sex on decision making in substance dependent individuals.

BACKGROUND: Substance dependence and antisocial psychopathology, such as a history of childhood conduct disorder (HCCD), are associated with impulsive or disadvantageous decision making and reduced working memory capacity (WMC). Reducing WMC via a working memory load increases disadvantageous decision making in healthy adults, but no previous studies have examined this effect in young adults with substance dependence and HCCD. METHOD: Young adults with substance dependence (SubDep; n=158, 71 female), substance dependence and HCCD (SubDep+HCCD; n=72, 24 female), and control participants (n=152, 84 female) completed a test of decision making (the Iowa Gambling Task; IGT) with or without a concurrent working memory load intended to tax WMC. Outcomes were (i) net advantageous decisions on the IGT, and (ii) preferences for infrequent- versus frequent-punishment decks. RESULTS: SubDep+HCCD men made fewer advantageous decisions on the IGT than control men without a load, but there were no group differences among women in that condition. Load was associated with fewer advantageous decisions for SubDep+HCCD women and control men, but not for men or women in the other groups. Participants showed greater preference for infrequent-punishment, advantageous decks under load as well. CONCLUSIONS: There are gender differences in the effects of substance dependence, HCCD, and working memory load on decision making on the IGT. Decision making by control men and SubDep+HCCD women suffered the most under load. Load increases preferences for less-frequent punishments, similar to a delay discounting effect. Future research should clarify the cognitive and neural mechanisms underlying these effects.

Dimensions of disinhibited personality and their relation with alcohol use and problems.

Although alcohol use disorders (AUDs) have been associated with different aspects of disinhibited personality and antisociality, less is known about the specific relationships among different domains of disinhibited personality, antisociality, alcohol use, and alcohol problems. The current study was designed to address three goals, (i) to provide evidence of a three-factor model of disinhibited personality (comprised of impulsivity [IMP], risk taking/low harm avoidance [RTHA], excitement seeking [ES]), (ii) to test hypotheses regarding the association between each dimension and alcohol use and problems, and (iii) to test the hypothesis that antisociality (social deviance proneness [SDP]) accounts for the direct association between IMP and alcohol problems, while ES is directly related to alcohol use. Measures of disinhibited personality IMP, RTHA, ES and SDP and alcohol use and problems were assessed in a sample of young adults (N=474), which included a high proportion of individuals with AUDs. Confirmatory factor analyses supported a three-factor model of disinhibited personality reflecting IMP, RTHA, and ES. A structural equation model (SEM) showed that IMP was specifically associated with alcohol problems, while ES was specifically associated with alcohol use. In a second SEM, SDP accounted for the majority of the variance in alcohol problems associated with IMP. The results suggest that aspects of IMP associated with SDP represent a direct vulnerability to alcohol problems. In addition, the results suggest that ES reflects a specific vulnerability to excessive alcohol use, which is then associated with alcohol problems, while RTHA is not specifically associated with alcohol use or problems when controlling for IMP and ES.