Effects of acute alcohol and driving complexity in older
and younger adults
Julianne L. Price
Ian R. Frazier
Sara Jo Nixon
Received: 24 July 2017 /Accepted: 27 November 2017 /Published online: 6 December 2017
Springer-Verlag GmbH Germany, part of Springer Nature 2017
Rationale Our previous work demonstrated differential neurobehavioral effects of low-dose alcohol consumption on older and
younger adults in a driving simulator. However, the ability to enhance or suppress a response in such context has yet to be
Objectives The current study contrasted older and younger drivers’ responses to specific stimuli (i.e., relevant, irrelevant) in
scenarios of differing complexity following low-dose acute alcohol administration.
Methods Healthy older (55–70) and younger (25–35) adults completed two driving scenarios (i.e., country and metropolis) both
before and after consuming beverages targeted to reach peak BrACs of 0.00, 0.04, or 0.065%. Throughout the simulation,
participants encountered relevant stimuli (e.g., pedestrians walking into the street) and irrelevant stimuli (e.g., pedestrians
walking parallel). Peak deceleration, range of steering, and distance until brake application were assessed within a 450-ft window
preceding each stimulus.
Results Following low-dose alcohol consumption, older adults shifted from a strategy using both deceleration and steering to
relying solely on deceleration in responding to relevant stimuli in the country. Older adults under both low and moderate alcohol
conditions displayed an inability to withhold responses to irrelevant stimuli in the metropolis.
Conclusion These findings are consistent with our prior work showing differential effects of low-dose alcohol on older, relative to
younger, adults. The interactive effects of age and alcohol, however, depend on stimulus type and environmental complexity.
Continued investigation of neurobehavioral mechanisms in ecologically valid paradigms is necessary for understanding the
implications of the combined impairing effects of alcohol and older age.
Keywords Breath alcohol concentrations (BrACs)
Both community-based and laboratory-derived data demon-
strate that breath alcohol concentrations (BrACs) below the
legal limit (0.08%) negatively affect performance on a variety
of neurobehavioral tasks (Abroms and Fillmore 2004;
Gilbertson et al. 2009) including driving (Calhoun and
Pearlson 2012; NHTSA 2015; Weafer and Fillmore 2012;
Sklar et al. 2014). Controlled laboratory studies have shown
that doses below 0.065% impact control of speed and steering
(Harrison and Fillmore 2011;Metsetal.2011; Ramaekers et al.
2000) with some suggesting impairments as low as 0.02%
(Irwin et al. 2017). Of interest, delayed responses to relevant
stimuli [e.g., red traffic light, potential collisions (Allen et al.
2009; Fillmore et al. 2008;LiuandHo2010)] are also observed
under the effects of acute low-dose alcohol.
Inappropriate braking reflected in the failure to activate
braking with sufficient time and/or pressure to avoid a colli-
sion or stop at a light is relatively easy to ascertain and of
obvious importance. A second category of inappropriate brak-
ing, referring to slowing or braking when unwarranted by
current traffic conditions, is equally pertinent and noted as
one of the most common behaviors of unsafe drivers (Klauer
* Julianne L. Price
Department of Psychiatry, University of Florida, PO Box 100256,
Gainesville, FL 32610, USA
Department of Psychology, University of Florida, PO Box 100256,
Gainesville, FL 32610, USA
Department of Clinical and Health Psychology, University of Florida,
PO Box 100256, Gainesville, FL 32610, USA
Psychopharmacology (2018) 235:887–896