Wacker J, Buser A, Lachenmayr B J
Augenklinik der Universität, München, Germany.
Ger J Ophthalmol. 1993 Aug;2(4-5):246-50.
Saccadic eye movements are required for the recognition of peripheral objects in road traffic. Their latencies largely determine reaction time in emergency situations. The aim of this study was to investigate the influence of stimulus and surround parameters on the temporal characteristics of saccadic eye movements under conditions of object size, contrast and luminance corresponding to nighttime traffic. Square stimuli of 1 degree or 5 degrees size were presented under an eccentricity of 5 degrees and 15 degrees. The luminance of the surround was 4 x 10(-4) cd/m2 and 1 cd/m2. More than approx. 2,000 saccades of 7 normal subjects were registered and evaluated with respect to the latency, maximal velocity, and frequency of secondary saccades. At high stimulus contrast, latency approaches a minimum of approx. 200 ms. Latency increases with decreasing contrast up to maximal values of more than 600 ms. Transforming the contrast values into a relative decibel scale shows that this increase in latency occurs at significantly higher relative contrast values under scotopic as compared with photopic conditions. Our results demonstrate that an overall latency of 200-300 ms is not adequate for the assessment of accidents, especially under the stimulus conditions of nighttime traffic.
扫视眼动对于识别道路交通中的周边物体是必需的。其潜伏期在很大程度上决定了紧急情况下的反应时间。本研究的目的是在与夜间交通相应的物体大小、对比度和亮度条件下，研究刺激和周边参数对扫视眼动时间特征的影响。在5度和15度的偏心度下呈现1度或5度大小的方形刺激。周边的亮度为4×10(-4)cd/m²和1cd/m²。记录并评估了7名正常受试者的2000多次扫视，涉及潜伏期、最大速度和二次扫视频率。在高刺激对比度下，潜伏期接近约200毫秒的最小值。潜伏期随着对比度降低而增加，直至超过600毫秒的最大值。将对比度值转换为相对分贝标度表明，与明视觉条件相比，在暗视觉条件下，潜伏期的这种增加发生在显著更高的相对对比度值时。我们的结果表明，200 - 300毫秒的总体潜伏期不足以评估事故，尤其是在夜间交通的刺激条件下。
