Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts.
Optom Vis Sci. 2020 Apr;97(4):239-248. doi: 10.1097/OPX.0000000000001501.
Despite similar levels of visual acuity and contrast sensitivity reductions, simulated central vision impairment increased response times to a much greater extent in older than in younger participants.
Driving is crucial for maintaining independence in older age, but age-related vision impairments and in-vehicle auditory distractions may impair driving safety. We investigated the effects of age, simulated central vision impairment, and auditory distraction on detection of pedestrian hazards.
Thirty-two normally sighted participants (16 younger and 16 older) completed four highway drives in a simulator and pressed the horn whenever they saw a pedestrian. Pedestrians ran toward the road on a collision course with the approaching vehicle. Simulated central vision impairment was achieved by attaching diffusing filters to a pair of laboratory goggles, which reduced visual acuity to 20/80 and contrast sensitivity by 0.35 log units. For drives with distraction, subjects listened to an audiobook and repeated out loud target words.
Simulated central vision impairment had a greater effect on reaction times (660-millisecond increase) than age (350-millisecond increase) and distraction (160-millisecond increase) and had a greater effect on older than younger subjects (828- and 492-millisecond increase, respectively). Simulated central vision impairment decreased safe response rates from 94.7 to 78.3%. Distraction did not, however, affect safety because older subjects drove more slowly when distracted (but did not drive more slowly with vision impairment), suggesting that they might have perceived greater threat from the auditory distraction than the vision impairment.
Older participants drove more slowly in response to auditory distraction. However, neither older nor younger participants adapted their speed in response to simulated vision impairment, resulting in unsafe detections. These results underline the importance of evaluating safety of responses to hazards as well as reaction times in a paradigm that flexibly allows participants to modify their driving behaviors.
尽管视力和对比敏感度的降低程度相似，但模拟中心视力损伤对老年人的反应时间影响要比年轻人大得多。
驾驶对于老年人保持独立性至关重要，但与年龄相关的视力障碍和车内听觉干扰可能会影响驾驶安全。我们研究了年龄、模拟中心视力障碍和听觉干扰对行人危险检测的影响。
32 名视力正常的参与者（16 名年轻参与者和 16 名年长参与者）在模拟器中完成了四次高速公路驾驶，每当他们看到行人时就按喇叭。行人朝着与迎面而来的车辆相撞的路线跑到路上。模拟中心视力损伤是通过在一副实验室护目镜上附加扩散滤镜来实现的，这会将视力降低到 20/80，并降低 0.35 个对数单位的对比敏感度。对于有干扰的驾驶，受试者听有声读物并大声重复目标单词。
模拟中心视力损伤对反应时间的影响（增加 660 毫秒）大于年龄（增加 350 毫秒）和干扰（增加 160 毫秒）的影响，对年长参与者的影响大于年轻参与者（分别增加 828 和 492 毫秒）。模拟中心视力损伤将安全反应率从 94.7%降低至 78.3%。然而，干扰并没有影响安全性，因为年长的参与者在分心时驾驶速度较慢（但在视力障碍时不会驾驶速度较慢），这表明他们可能认为听觉干扰比视力障碍更具威胁性。
年长的参与者对听觉干扰的反应较慢。然而，无论是年长还是年轻的参与者都没有根据模拟视力损伤来调整他们的速度，导致不安全的检测。这些结果强调了在一个灵活的范式中评估对危险的反应安全性以及反应时间的重要性，该范式允许参与者灵活地调整他们的驾驶行为。
