Objective Level of Alertness and Inhibitory Control Predict Highway Driving Impairment in Adults With ADHD.

Objective: It remains unclear whether daytime impairments in ADHD patients are better explained by an altered level of alertness and/or by cognitive deficits. The aim of this study was to determine the respective contribution of these factors on driving performance in ADHD adults. Method: ADHD adults (n = 39) and healthy controls (n = 18) underwent a nocturnal polysomnography (PSG) followed by a Maintenance of Wakefulness Test (MWT), a simulated driving task, and a neuropsychological evaluation. Results: ADHD patients had shorter mean sleep latency on the MWT and worse driving performance than controls. They also made more errors on attention and executive functioning tests. Logistic regression analyses showed that inhibition deficits and objective daytime sleepiness predicted highway driving performance in ADHD. Conclusion: Our study shows that not only inhibitory control deficits but also pathological level of alertness independently contribute to highway driving impairment in ADHD patients, providing a better understanding of the pathophysiological mechanisms involved in ADHD.

The sensitivity of laboratory tests assessing driving related skills to dose-related impairment of alcohol: A literature review.

Laboratory tests assessing driving related skills can be useful as initial screening tools to assess potential drug induced impairment as part of a standardized behavioural assessment. Unfortunately, consensus about which laboratory tests should be included to reliably assess drug induced impairment has not yet been reached. The aim of the present review was to evaluate the sensitivity of laboratory tests to the dose dependent effects of alcohol, as a benchmark, on performance parameters. In total, 179 experimental studies were included. Results show that a cued go/no-go task and a divided attention test with primary tracking and secondary visual search were consistently sensitive to the impairing effects at medium and high blood alcohol concentrations. Driving performance assessed in a simulator was less sensitive to the effects of alcohol as compared to naturalistic, on-the-road driving. In conclusion, replicating results of several potentially useful tests and their predictive validity of actual driving impairment should deserve further research. In addition, driving simulators should be validated and compared head to head to naturalistic driving in order to increase construct validity.

Association of Subjective and Interpretive Drowsiness with Facial Dynamic Changes in Simulator Driving.

BACKGROUND: Major injuries and death in accidents have roots in drowsiness. Sleepiness is a main result of insufficient sleep. It is vital to explore drowsiness and its level. There are various sorts of methods in the forms of subjective and objective approaches. The goal of this study was to detect the association of subjective and interpretive drowsiness with facial dynamic changes. METHODS: This experimental study was conducted in the Virtual Reality Lab, in Khaje-Nasir Toosi University of Technology, Tehran Iran on 40 drivers in 2015. Facial dynamic changes (eyes, mouth and eyebrows), Karolinska Sleepiness Scale (KSS) and Observer Rating of Drowsiness (ORD) were applied. The neural network and Viola-Jones were utilized for facial characteristics detection. Statistical analyses were conducted using SPSS version 21. RESULTS: Thirty-four drivers got drowsy during the test. They were selected randomly among suburban drivers at the age in a range of 26 to 60 yr old. Descriptive statistics of the dynamic changes in eyebrows, mouth and eyes showed that these features were of meaningful changes with respect to the level of drowsiness during driving. A relationship between the dynamic changes of facial features and ORD was recognized. Moreover, there was a significant relationship between facial expression and drowsiness (P<0.05). CONCLUSIONS: Results of KSS and ORD illustrated that there were dynamic changes in eyes and mouth and eyebrow parameters while driver felt sleepy. This research is helpful in a way that specific changes in elements of face could be effective to provide tools to predict drowsiness.