Impact of cannabis inhalation on driving skills in occasional smokers
Détails
Etat: Public
Version: de l'auteur⸱e
ID Serval
serval:BIB_41DA66E03DB4
Type
Actes de conférence (partie): contribution originale à la littérature scientifique, publiée à l'occasion de conférences scientifiques, dans un ouvrage de compte-rendu (proceedings), ou dans l'édition spéciale d'un journal reconnu (conference proceedings).
Sous-type
Abstract (résumé de présentation): article court qui reprend les éléments essentiels présentés à l'occasion d'une conférence scientifique dans un poster ou lors d'une intervention orale.
Collection
Publications
Institution
Titre
Impact of cannabis inhalation on driving skills in occasional smokers
Titre de la conférence
Tri-Annual Meeting of the International Council on Alcohol, Drugs and Traffic Safety
Adresse
Oslo, Norway, August 22-26, 2010
Statut éditorial
Publié
Date de publication
2010
Langue
anglais
Résumé
Objectives: Our aim was to study the brain regions involved in a divided attention tracking task related to driving in
occasional cannabis smokers. In addition we assessed the relationship between THC levels in whole blood
and changes in brain activity, behavioural and psychomotor performances.
Methods: Twenty-one smokers participated to two independent cross-over fMRI experiments before and after
smoking cannabis and a placebo. The paradigm was based on a visuo-motor tracking task, alternating active
tracking blocks with passive tracking viewing and rest condition. Half of the active tracking conditions
included randomly presented traffic lights as distractors.
Blood samples were taken at regular intervals to determine the time-profiles of the major cannabinoids.
Their levels during the fMRI experiments were interpolated from concentrations measured by GCMS/
MS just before and after brain imaging.
Results: Behavioural data, such as the discard between target and cursor, the time of correct tracking and the reaction
time during traffic lights appearance showed a statistical significant impairment of subject s skills
due to THC intoxication. Highest THC blood concentrations were measured soon after smoking and ranged between 28.8 and 167.9
ng/ml. These concentrations reached values of a few ng/ml during the fMRI.
fMRI results pointed out that under the effect of THC, high order visual areas (V3d) and Intraparietal sulcus
(IPS) showed an higher activation compared to the control condition. The opposite comparison showed
a decrease of activation during the THC condition in the anterior cingulate gyrus and orbitofrontal
areas. In these locations, the BOLD showed a negative correlation with the THC level.
Conclusion: Acute cannabis smoking significantly impairs performances and brain activity during active tracking
tasks, partly reorganizing the recruitment of brain areas of the attention network. Neural activity in the
anterior cingulate might be responsible of the changes in the cognitive controls required in our divided attention
task.
occasional cannabis smokers. In addition we assessed the relationship between THC levels in whole blood
and changes in brain activity, behavioural and psychomotor performances.
Methods: Twenty-one smokers participated to two independent cross-over fMRI experiments before and after
smoking cannabis and a placebo. The paradigm was based on a visuo-motor tracking task, alternating active
tracking blocks with passive tracking viewing and rest condition. Half of the active tracking conditions
included randomly presented traffic lights as distractors.
Blood samples were taken at regular intervals to determine the time-profiles of the major cannabinoids.
Their levels during the fMRI experiments were interpolated from concentrations measured by GCMS/
MS just before and after brain imaging.
Results: Behavioural data, such as the discard between target and cursor, the time of correct tracking and the reaction
time during traffic lights appearance showed a statistical significant impairment of subject s skills
due to THC intoxication. Highest THC blood concentrations were measured soon after smoking and ranged between 28.8 and 167.9
ng/ml. These concentrations reached values of a few ng/ml during the fMRI.
fMRI results pointed out that under the effect of THC, high order visual areas (V3d) and Intraparietal sulcus
(IPS) showed an higher activation compared to the control condition. The opposite comparison showed
a decrease of activation during the THC condition in the anterior cingulate gyrus and orbitofrontal
areas. In these locations, the BOLD showed a negative correlation with the THC level.
Conclusion: Acute cannabis smoking significantly impairs performances and brain activity during active tracking
tasks, partly reorganizing the recruitment of brain areas of the attention network. Neural activity in the
anterior cingulate might be responsible of the changes in the cognitive controls required in our divided attention
task.
Création de la notice
24/02/2011 12:52
Dernière modification de la notice
20/08/2019 13:42
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