Brown Timothy L, Richard Christian, Meghdadi Amir, Poole Jared, Fink Abigail, Stevanović Karić Marija, McConnell Marissa, Rupp Greg, Schmitt Rose, Gaffney Gary G, Milavetz Gary, Berka Chris
National Advanced Driving Simulator, The University of Iowa, Iowa City, Iowa.
Advanced Brain Monitoring, Carlsbad, California.
Traffic Inj Prev. 2020 Oct 12;21(sup1):S130-S134. doi: 10.1080/15389588.2020.1814957. Epub 2020 Sep 25.
As cannabis use becomes more widely accepted, there is growing interest in its effects on brain function, specifically how it may impact daily functional activities such as driving, operating machinery, and other safety-related tasks. There are currently no validated methods for quantifying impairment from acute cannabis intoxication. The objective of this study was to identify neurophysiological correlates associated with driving simulator performance in subjects who were acutely intoxicated with cannabis. These signatures could help create an EEG-based profile of impairment due to acute cannabis intoxication.
Each subject completed a three-visit study protocol. Subjects were consented and screened on the first visit. On the second and third visits, subjects were administered either 500 mg of cannabis with 6.7% delta-9-tetrahydrocannabinol (THC) or placebo using a Volcano© Digit Vaporizer in a counterbalanced fashion. EEG was acquired from subjects as they performed a series of neurocognitive tasks and an approximately 45-minute simulated drive that included a rural straight-away absent of any other cars or obstacles during the final 10 minutes.EEG data was acquired using a STAT X24 wireless sensor headset during a simulated driving scenario from 10 subjects during the THC and placebo visits. Metrics of driving performance were extracted from the driving simulator and synchronized with EEG data using a common clock.
A within-subjects analysis showed that the standard deviation of lane position (SDLP) was significantly worse and heart rate was elevated during the dosed visit compared to the placebo visit. Consistent with our prior findings, EEG power in the Theta frequency band (4-7 Hz) in the dosed condition was significantly decreased from the placebo condition. Theta power was negatively correlated with the SDLP driving performance metric, while there were no significant correlations between any EEG measure and SDLP in the placebo condition.
These results, in combination with prior work on the effect of cannabis intoxication during neurocognitive tasks, suggest that neurophysiological signatures associated with acute cannabis intoxication are robust and consistent across tasks, and that these signatures are significantly correlated with impaired performance in a driving simulator. Taken together, EEG data acquired during a short neurocognitive testbed and during a simulated drive may provide specific profiles of impairment associated with acute cannabis intoxication. Further research is needed to establish the impaired cognitive processes associated with these EEG biomarkers.
随着大麻使用越来越被广泛接受，人们对其对脑功能的影响，特别是对日常功能活动（如驾驶、操作机械和其他与安全相关的任务）的影响越来越感兴趣。目前尚无经过验证的方法来量化急性大麻中毒导致的功能损害。本研究的目的是确定急性大麻中毒受试者中与驾驶模拟器表现相关的神经生理学关联。这些特征有助于创建基于脑电图的急性大麻中毒所致功能损害概况。
每位受试者完成一个三次访视的研究方案。在首次访视时获得受试者的同意并进行筛查。在第二次和第三次访视时，使用Volcano©数字蒸发器以平衡的方式给受试者服用500毫克含6.7% Δ-9-四氢大麻酚（THC）的大麻或安慰剂。在受试者执行一系列神经认知任务以及大约45分钟的模拟驾驶过程中采集脑电图，模拟驾驶在最后10分钟包括一段没有其他车辆或障碍物的乡村直道。在THC和安慰剂访视期间，使用STAT X24无线传感器头戴式设备从10名受试者在模拟驾驶场景中采集脑电图数据。从驾驶模拟器中提取驾驶性能指标，并使用一个共同的时钟与脑电图数据同步。
受试者内分析表明，与安慰剂访视相比，给药访视期间车道位置标准差（SDLP）显著变差，心率升高。与我们之前的研究结果一致，给药状态下θ频段（4 - 7赫兹）的脑电图功率与安慰剂状态相比显著降低。θ功率与SDLP驾驶性能指标呈负相关，而在安慰剂状态下，任何脑电图测量与SDLP之间均无显著相关性。
这些结果，结合之前关于神经认知任务期间大麻中毒影响的研究工作，表明与急性大麻中毒相关的神经生理学特征在不同任务中是稳健且一致的，并且这些特征与驾驶模拟器中的表现受损显著相关。总体而言，在简短的神经认知测试平台和模拟驾驶期间采集的脑电图数据可能提供与急性大麻中毒相关的特定功能损害概况。需要进一步研究以确定与这些脑电图生物标志物相关受损的认知过程。
