Journal article
Impact of cannabis and low alcohol concentration on divided attention tasks during driving
Traffic injury prevention, Vol.21(S1), pp.S123-S129
10/12/2020
DOI: 10.1080/15389588.2020.1814956
PMID: 33035082
Abstract
Objective To assess divided-attention performance when driving under the influence of cannabis with and without alcohol. Three divided-attention tasks were performed following administration of placebo, cannabis, and/or alcohol. Methods Healthy adult cannabis users participated in 6 sessions, receiving combinations of cannabis (placebo/low-THC/high-THC) and alcohol (placebo/active) in randomized order, separated by washout periods of >= 1 week. At 0.5 hours post-dosing, participants performed simulator drives in the University of Iowa National Advanced Driving Simulator (NADS-1), a full vehicle cab simulator with a 360 degrees horizontal field of view and motion base that provides realistic feedback. Drives contained repeated instances of three tasks: a side-mirror task (reaction to a triangle appearing in the side-mirrors), an artist-search task (select a specified artist from a navigable menu on the vehicle's console), and a message-reading task (read aloud a message displayed on the console). Blood THC and breath alcohol concentration (BrAC) were interpolated using individual power curves from samples collected approximately 0.17, 0.42, 1.4, and 2.3 hours post-dose. Driving measures during tasks were compared to equal-duration control periods occurring just prior to the task. Performance shifts, task completion, and lane departures were modeled relative to blood THC and BrAC using mixed-effects regression models. Results Each 1 mu g/L increase in blood THC concentration predicted increased odds of failing to complete the artist-search task (OR: 1.05, 95% CI: 1.01-1.11, p = 0.046), increased odds of selecting at least one incorrect response (OR: 1.05, 95% CI: 1.00-1.09, p = 0.041), declines in speed during the side-mirror task (0.005 m/s, 95% CI: 0.001-0.009, p = 0.023), and longer lane departure durations during the artist-search task (0.74% of task-period, 95% CI: 0.12-1.36 p = 0.020). BrAC (approximately 0.05%) was not associated with task performance, though each 0.01 g/210 L increase predicted longer departure durations during the side-mirror task (1.41% of task-period, 95% CI: 0.08-2.76, p = 0.040) and increased standard deviation of lane position in the message-reading task (0.61 cm, 95% CI: 0.14-1.08, p = 0.011). Conclusions With increasing medical and legal cannabis use, understanding the impact of acute cannabis use on driving performance, including divided-attention, is essential. These data indicate that impaired divided-attention performance is a safety concern.
Details
- Title: Subtitle
- Impact of cannabis and low alcohol concentration on divided attention tasks during driving
- Creators
- Ryan E. Miller - Grinnell Coll, Dept Math & Stat, Grinnell, IA 50112 USATimothy L. Brown - Univ Iowa, Natl Adv Driving Simulator, Iowa City, IA 52242 USAStella Lee - Grinnell CollegeIshaan Tibrewal - Grinnell CollegeGary G. Gaffney - Univ Iowa, Natl Adv Driving Simulator, Iowa City, IA 52242 USAGary Milavetz - University of IowaRebecca L. Hartman - NIDA, Chem & Drug Metab, Intramural Res Program, NIH, Baltimore, MD USADavid A. Gorelick - National Institute on Drug AbuseRichard Compton - National Highway Traffic Safety AdministrationMarilyn A. Huestis - National Institute on Drug Abuse
- Resource Type
- Journal article
- Publication Details
- Traffic injury prevention, Vol.21(S1), pp.S123-S129
- DOI
- 10.1080/15389588.2020.1814956
- PMID
- 33035082
- NLM abbreviation
- Traffic Inj Prev
- ISSN
- 1538-9588
- eISSN
- 1538-957X
- Publisher
- Taylor & Francis
- Number of pages
- 7
- Grant note
- DTNH22-11-D-00237/004 / University of Iowa DTNH22-11-D-00237/004 / National Highway Traffic Safety Administration
- Language
- English
- Date published
- 10/12/2020
- Academic Unit
- Pharmacy; Psychiatry; Pharmaceutical Sciences and Experimental Therapeutics; Pharmacy Practice and Science; Injury Prevention Research Center
- Record Identifier
- 9984365892602771
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