Psychological Science

The present study examined the effects of alcohol on the ability to execute and inhibit behavior in a context in which preliminary information signaled the likelihood that a response should be executed or suppressed. Social drinkers (N ϭ 12) performed a cued go/no-go task that required quick responses to go targets and suppression of responses to no-go targets. Performance was tested under 3 doses of alcohol: 0.65 g/kg, 0.45 g/kg, and 0.0 g/kg (placebo). Alcohol had no effect on inhibition and execution when cues correctly signaled these actions. By contrast, alcohol impaired inhibition and execution in a dose-dependent manner when cues incorrectly signaled actions. These findings are consistent with a resource limitation account of alcohol impairment.

Previous research has demonstrated that adults with attention deficit/hyperactivity disorder (ADHD) are more likely to experience driving-related problems, which suggests that they may exhibit poorer driving performance. However, direct experimental evidence of this hypothesis is limited. The current study involved 2 experiments that evaluated driving performance in adults with ADHD in terms of the types of driving decrements typically associated with alcohol intoxication. Experiment 1 compared the simulated driving performance of 15 adults with ADHD to 23 adult control participants, who performed the task both while sober and intoxicated. Results showed that sober adults with ADHD exhibited decrements in driving performance compared to sober controls, and that the profile of impairment for the sober ADHD group did in fact resemble that of intoxicated drivers at the blood alcohol concentration level for legally impaired driving in the United States. Driving impairment of the intoxicated individuals was characterized by greater deviation of lane position, faster and more abrupt steering maneuvers, and increased speed variability. Experiment 2 was a dose-challenge study in which 8 adults with ADHD and 8 controls performed the driving simulation task under 3 doses of alcohol: 0.65g/kg, 0.45g/kg, and 0.0g/kg (placebo). Results showed that driving performance in both groups was impaired in response to alcohol, and that individuals with ADHD exhibited generally poorer driving performance than did controls across all dose conditions. Together the findings provide compelling evidence to suggest that the cognitive and behavioral deficits associated with ADHD might impair driving performance in such a manner as to resemble that of an alcohol intoxicated driver. Moreover, alcohol might impair the performance of drivers with ADHD in an additive fashion that could considerably compromise their driving skill even at blood alcohol concentrations below the legal limit.

This research examined the relationship between self-reported cognitive preoccupation with drinking and self-reported and ad lib measures of alcohol consumption in male and female college students. Fifty undergraduates rated their degree of preoccupation with drinking using the Cognitive and Emotional Preoccupation scale and then participated in an individualized taste-rating task, an unobtrusive laboratory measure for determining ad lib alcohol consumption. Regression results showed that individual differences in emotional preoccupation with alcohol predicted self-reported consumption and actual laboratory alcohol consumption, only for women and not for men. This research shows that emotional preoccupation with alcohol appears to be an important factor in determining rates of drinking in college-age women and may be an important factor in identifying those individuals at risk of future problems with alcohol.

Background:  Binge drinking (heavy episodic alcohol use) is associated with high rates of impaired driving and myriad alcohol-related accidents. However, the underlying reasons for the heightened accident risk in this demographic group are not known. This research examined acute alcohol effects on simulated driving performance and subjective ratings of intoxication and driving ability in binge and nonbinge drinkers.Methods:  Young social drinking college students (24 binge drinkers and 16 nonbinge drinkers) participated in this study. Participants attended a session during which they received a moderate dose of alcohol (0.65 g/kg) and a session during which they received a placebo. A simulated driving task measured participants’ driving performance in response to each dose. Subjective responses to each dose were also assessed, including ratings of sedation, stimulation, and driving ability.Results:  The acute dose of alcohol impaired multiple aspects of driving performance in both binge and nonbinge drinkers. Under alcohol, all participants had greater difficulty in maintaining their lane position, maintaining the appropriate speed and made multiple driving errors compared to placebo performance. By contrast, compared with nonbinge drinkers, binge drinkers reported feeling less sedated by the alcohol and reported having a greater ability to drive following the acute dose of alcohol.Conclusions:  Reduced subjective intoxication and perceived driving impairment in binge drinkers may account for the greater accident risk in this demographic group. Binge drinkers may lack the internal sedation cue that helps them accurately assess that they are not able to effectively drive a vehicle after drinking.

The present study examined the effects of d -amphetamine on the ability to execute and inhibit behavior in a context where preliminary information signaled the likelihood that a response should be executed or suppressed. Eight adults (5 men and 3 women) with a history of stimulant abuse performed a cued go no-go task that required quick responses to go targets and suppression of responses to no-go targets. Performance was tested under four oral doses of d -amphetamine, 0 (placebo), 5, 10 and 20 mg, administered double-blind and in mixed order. d -Amphetamine produced a dose-dependent increase in inhibitory failures following invalid go cues and had no effect on inhibitory failures following valid no-go cues. d -Amphetamine had little effect on response execution as measured by reaction time. Subjective and physiological effects of d -amphetamine were also observed. The findings demonstrate that stimulant effects on fundamental aspects of behavioral control can be mediated by environmental cues that alter response tendencies. Identification of environmental conditions in which stimulants are likely to disinhibit behavior could provide insight into mechanisms that underlie the association between long-term stimulant use and poor impulse control. #

This study examined the effects of alcohol on the ability to execute and inhibit behavior in a context in which preliminary information signaled the likelihood that a response should be executed or suppressed. Adults (N ϭ 24) performed a cued go/no-go task that required quick responses to go targets and suppression of responses to no-go targets. Cue dependency was manipulated by varying the predictive validity of the cues, and performance was tested under 3 doses of alcohol: 0.00 g/kg, 0.45 g/kg, and 0.65 g/kg. Dose-dependent increases in cue dependence were only observed with highly predictive cues. Results suggest that alcohol-induced increases in stimulus control over behavior might be most likely in situations when stimulus control over behavior has already been established.

High rates of binge drinking and alcohol-related problems, including drinking and driving, occur among college students. Underlying reasons for the heightened impaired driving rates in this demographic group are not known. The authors hypothesized that acute tolerance to the interoceptive cues of intoxication may contribute to these maladaptive decisions to drive in binge drinkers. Groups of binge-drinking and non-binge-drinking college students (N ϭ 28) attended sessions during which they received a moderate dose of alcohol (0.65 g/kg) or a placebo. The development of acute tolerance to subjective ratings of intoxication and simulated driving performance was assessed by comparing measures taken during the ascending phase and descending phases of the blood alcohol curve. Compared with placebo, alcohol increased ratings of intoxication and impaired multiple aspects of simulated driving performance in both binge and non-binge drinkers. During the descending phase of the blood alcohol curve, binge drinkers showed acute tolerance to alcohol's effect on subjective intoxication, and this effect was accompanied by an increased rating of willingness to drive. By contrast, non-binge drinkers showed no acute tolerance.

Heavy episodic alcohol use, or binge drinking, is a serious public health problem. Binge drinking is endemic in college students and has resulted in numerous alcohol-related tragedies, including acute alcohol poisonings, falls, and automobile collisions. Such negative outcomes might occur because binge drinkers are generally more impulsive, and this impulsivity might be exacerbated under alcohol. The purpose of this study was to examine this hypothesis by comparing the acute effects of alcohol on a cognitive measure of behavioral control in binge and nonbinge drinkers. The results indicated that binge drinkers act more impulsively and report feeling more stimulated under an acute 0.65 g/kg dose of alcohol compared to nonbinge drinkers. The present finding of a heightened disinhibitory reaction to alcohol in binge drinkers may help explain the link between impulsivity and problem drinking at a more fundamental level of behavioral control.

The present study examined the effects of alcohol on the ability to execute and inhibit behavior in a context in which preliminary information signaled the likelihood that a response should be executed or suppressed. Social drinkers (N ϭ 12) performed a cued go/no-go task that required quick responses to go targets and suppression of responses to no-go targets. Performance was tested under 3 doses of alcohol: 0.65 g/kg, 0.45 g/kg, and 0.0 g/kg (placebo). Alcohol had no effect on inhibition and execution when cues correctly signaled these actions. By contrast, alcohol impaired inhibition and execution in a dose-dependent manner when cues incorrectly signaled actions. These findings are consistent with a resource limitation account of alcohol impairment.

Research shows that prior behavioral training in a challenging environment reduces alcoholinduced impairment on simple psychomotor tasks. However, no studies have examined if this relationship generalizes to driving performance. The present study examined simulated driving performance and tested the hypothesis that a challenging training history would protect against the impairing effects of alcohol on driving performance. The challenging training history involved driving in a visually-impoverished environment. Thirty adults were randomly assigned to one of three groups. Two groups were tested under alcohol (0.65 g/kg) after prior experience performing the task under either a visually-impoverished environment or a normal visual environment. The remaining group served as a control and was trained and tested under the visually-impoverished condition environment. Results showed that individuals trained in the impoverished environment displayed sober levels of performance when their performance was subsequently tested under alcohol. By contrast, volunteers trained in a normal environment showed impairment under alcohol. The findings suggest that differences in driving training history can affect a driver's sensitivity to the impairing effects of alcohol.

Rationale Model-based assessments of behavioral control have been used to study the acute effects of alcohol on the ability to execute and inhibit behavioral responses. Response inhibition appears more vulnerable to the impairing effects of alcohol than response execution. Current information processing models have yet to account for this observation. Objectives The present study used a reductionist approach to determine if the particular vulnerability of response inhibition to the effects of alcohol occurs at the level of the action (motor program). The study examined the effects of alcohol on the ability to execute and inhibit behavior in a context in which preliminary information signaled the likelihood that a response should be executed or suppressed. The engagement and disengagement of responses were directly compared under alcohol. Methods Adults (N=24) performed a cued go/no-go task that required quick responses to go targets and suppression of responses to no-go targets. Response requirements were manipulated by varying the nature of the action required whereby half of the participants made key press responses (response engagement) and the other half released ongoing key presses (response disengagement). Performance was tested under three doses of alcohol: 0.00, 0.45, and 0.65 g/kg. Results Dose-dependent increases in commission errors were only observed with response engagement and not with response disengagement. Reaction times were faster for response engagement than response disengagement. Conclusions Response disengagement affords some protection against alcohol-induced impairment of inhibition, indicating that not all aspects of motor processing requiring inhibition are equally impaired by alcohol.

Rationale Studies have shown that expectations of alcohol-induced impairment can produce adaptive responses to alcohol that reduce the degree of behavioral impairment displayed. However, compensatory effects have been variable for cognitive and psychomotor tasks. Objectives Using a model-driven approach to understanding behavioral control, the present study examined compensatory and impairment effects following the expectation and actual administration of alcohol on the ability to inhibit and activate behavior. Methods Social drinkers (N=17) performed a cued go/no-go task that required quick responses to go targets and inhibition of responses to no-go targets under four conditions: no treatment, alcohol expectancy (placebo), 0.45 g/kg alcohol, and 0.65 g/kg alcohol. Results Inhibitory and activational aspects of behavioral control were impaired by both active doses of alcohol. Alcohol slowed response activation and increased failures to inhibit responses in a dose-dependent manner. Subjects also displayed a small, but statistically significant, compensatory improvement in inhibitory control in response to the expectation of alcohol. Moreover, individual differences in the compensatory response were related to differences in alcohol impairment. Those who displayed greater compensatory responses to placebo displayed the least impairment in response to alcohol. Conclusions By modeling behavioral control as the net effect of countervailing activational and inhibitory influences, the study suggests that fundamental mechanisms of control might not display uniform compensatory reactions to alcohol-related cues. Greater consideration of how alcohol-related expectancies shape behaviors under the drug should lead to a better understanding of individual differences with respect to risk for alcohol abuse.

Six experiments were undertaken to explore factors affecting young rats' (Rattus norvegicus) frequencies of stealing food from conspecifics when identical food is available in surplus. It was found that (a) rats would walk across a bed of pellets to steal the particular pellet a peer was eating, (b) frequency of stealing within a pair did not decrease over days, (c) rats stole unfamiliar foods more frequently than familiar foods, (d) younger rats stole from older rats more frequently than older rats stole from younger ones, (e) hungry rats stole more frequently than replete rats, and (f) rats that had stolen a pellet of unfamiliar food from an anesthetized conspecific subsequently exhibited an enhanced preference for that food. Results suggest that food stealing is a mode of active seeking of information about what foods to eat.

a b s t r a c t a r t i c l e i n f o Impulsivity may have different facets that contribute to drinking patterns in young people. This research examined how aspects of impulse control, especially the ability to inhibit a response, predicted recent alcohol use patterns in young social drinkers. Participants (N = 109) between the ages of 18 and 21 performed a cued go/no-go task that required quick responses to go targets and the inhibition of responses to no-go targets. Participants also completed several questionnaires that assessed drinking habits (TLFB) and selfreported impulsivity (BIS-11). Regression analyses revealed that both the impulsivity questionnaire scores and the inhibitory failures observed on the behavioral task predicted various aspects of recent drinking. However, only the inhibitory failures from the behavioral task, and not the impulsivity questionnaire scores, predicted the highest number of drinks consumed on one occasion during the past month. These findings are consistent with the notion that impulsivity may have different components that may be contributing the drinking patterns, and this research suggests that the inability to withhold a response is a strong predictor of the binge use of alcohol.