Effect of driver distraction and low alcohol concentrations on useful field of view and frequency‐doubling technology perimetry

Abstract. Purpose: To investigate the effects of a mental psychometric task that simulates the distraction effect of a hands‐free mobile phone and of low alcohol concentrations (0.3–0.5 g/l) on two tests: the useful field of view (UFOV) and frequency‐doubling technology (FDT) perimetry. Methods: Thirty‐seven healthy young vehicle drivers aged 22 ± 3 years were subjected to a computer version of the UFOV test and FDT perimetry, undertaken according to a counterbalanced within‐subject design. The tests were performed in two sessions (an ‘alcohol session’ and a ‘sober session’), while undertaking or not undertaking a psychometric test [the Paced Auditory Serial Addition Test (PASAT)] to simulate the effect of distraction. Each subject was instructed to concentrate on the PASAT while taking each test. Results: UFOV scores were affected when the PASAT was performed simultaneously ( P < 0.0001) in that longer times were required to identify a central target and the location of a peripheral target. FDT perimetry was affected by the addition of the PASAT, with a significant reduction in mean sensitivity and a localized sensitivity loss [pattern standard deviation (PSD) >6 dB]. Test times, false‐positive and negative catch trial responses were all increased. However, the UFOV test and FDT perimetry results were not significantly affected by a low alcohol concentration. Conclusion: Distraction significantly affects performance in the UFOV test and frequency‐doubling technology perimetry. Our findings suggest that using a hands‐free mobile phone while driving may lead to a low‐to‐moderate crash risk in young adults with normal visual function.