Browsing by Author "Plawecki, Martin Henry"

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    Alcohol intoxication progressively impairs drivers' capacity to detect important environmental stimuli
    (Elsevier, 2018) Plawecki, Martin Henry; Koskie, Sarah; Kosobud, Ann; Justiss, Michael D.; O'Connor, Sean; Psychiatry, School of Medicine
    Rationale Alcohol intoxication impairs driving skills, leading to an increased frequency of accidents and crash fatalities. Inebriation may specifically impair environmental vigilance, reducing the driver's capacity for attention to stimuli that are relevant to successful navigation. Objectives We examined the separate and interactive effects of breath alcohol concentration (BrAC) and simulated driving scenario on the capacity to correctly identify visual stimuli embedded in the environment. Methods Ten healthy young adult drivers (6 males; 4 females) each performed 4 driving scenarios at each of 3 steady breath alcohol concentration levels (0, 60 and 100 mg/dl). Scenarios were based on speed or distance keeping while navigating a rural 2-lane road in daytime or nighttime conditions. Drivers pressed a button on the steering wheel corresponding to the direction of an arrow (up or down) which appeared briefly on road signs embedded in the environment, either overhead or on the roadside. Results Increasing level of BrAC and subjective scenario difficulty manifested significant, separate, but not interactive influences in association with the number of arrows correctly identified. Significant impairments could be detected at a level of BrAC below the current American limit for legal operation of a motor vehicle. Conclusions Environmental vigilance is subject to impairment by either/both alcohol intoxication and driving conditions.
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    Sex Differences in Motivation to Self‐Administer Alcohol After 2 Weeks of Abstinence in Young‐Adult Heavy Drinkers
    (Wiley, 2018) Plawecki, Martin Henry; White, Kurt; Kosobud, Ann E. K.; Grahame, Nicholas; Zimmermann, Ulrich S.; Crabb, David; O'Connor, Sean; Psychiatry, School of Medicine
    Background Studies in animal models document that forced abstinence from usual consumption of alcohol changes subsequent seeking and consumption, with increases or decreases depending on the species, duration of abstinence, number of deprivations, and sex. Human laboratory‐based alcohol deprivation studies are rare. Methods We conducted a 2‐session, within‐participant, randomized‐order comparison of intravenous, progressive ratio, alcohol self‐administration during 2.5 hours of progressive work for alcohol and/or vehicle; once while the participants pursued their usual drinking habits and once after 2 weeks of closely monitored, voluntary outpatient abstinence from alcohol. The schedule of work for rewards and the incremental increases in breath alcohol concentration following completion of an alcohol work‐set were identical across participants. Fifty young‐adult (27 men), heavy‐drinking participants completed both sessions. Our primary hypothesis was that motivation to work for alcohol after 2 weeks of abstinence would be greater in participants with a weekly binge pattern of drinking, compared to those who regularly drink heavily, and we intended to explore associations with biological family history of alcoholism and sex. Results We detected no change in work for alcohol associated with recent drinking history. However, females, on average, increased their work for alcohol upon resumption after 2 weeks of abstinence (mean ± SEM = +16.3 ± 9.6%), while males decreased that work (−24.8 ± 13.8%). The sex difference was substantial and significant (p < 0.03), with a medium effect size (Cohen's d = 0.63). Conclusions We believe a more comprehensive study of mechanisms underlying the sex differences in the human postabstinence response is warranted.