Table1_The effect of a startle-based warning, age, sex, and secondary task on takeover actions in critical autonomous driving scenarios.DOCX

Introduction: In highly autonomous driving scenarios, it is critical to identify strategies to accelerate reaction times since drivers may take too long to take over control of the vehicle. Previous studies reported that an Acoustic Startling Pre-Stimulus (ASPS, i.e., a loud warning preceding an action) accelerated reaction times in simple ankle flexion exercises.
Methods: In this study, we examined if an ASPS warning leads to shorter takeover reaction times in a sled-simulated evasive swerving maneuver. Twenty-eight participants (seven male adults, seven male teenagers, seven female adults, and seven female teenagers) were instructed to align a marker on the steering wheel with a marker on a lateral post as fast as they could as soon as the lateral sled perturbation (0.75 g) started. Four conditions were examined: with and without an ASPS (105 dB, played 250 ms before sled perturbation for 40 ms), and with and without a secondary task (i.e., texting). A catch trial (ASPS only) was used to minimize anticipation. Human kinematics were captured with an 8-camera 3D motion capture system.
Results: Results showed that the drivers’ hands lifted towards the steering wheel more quickly with the ASPS (169 ± 55 ms) than without (194 ± 46 ms; p = 0.01), and that adult drivers touched the steering wheel quicker with the ASPS (435 ± 54 ms) than without (470 ± 33 ms; p = 0.01). Similar findings were not observed for the teen drivers. Additionally, female drivers were found to lift their hands towards the steering wheel faster than male drivers (166 ± 58 ms vs. 199 ± 36 ms; p = 0.009).
Discussion: Our findings suggest that the ASPS may be beneficial to accelerate driver reaction times during the initiation of a correction maneuver, and that autonomous vehicle warnings may need to be tailored to the age and sex of the driver.

引言：在高度自动驾驶场景中，由于驾驶员接管车辆的反应时长可能过长，因此亟需确定可缩短反应时长的应对策略。既往研究表明，声学惊吓预刺激（Acoustic Startling Pre-Stimulus，ASPS，即动作前的强声预警）可在简单的踝关节屈曲训练中缩短反应时长。
方法：本研究旨在探究ASPS预警是否可在雪橇模拟避闪转向操纵中缩短接管反应时长。共招募28名受试者（7名成年男性、7名青少年男性、7名成年女性、7名青少年女性），要求受试者在横向雪橇扰动（0.75g）启动后，尽快将方向盘上的标记与侧向立柱上的标记对齐。实验共设置四种实验条件：有无ASPS预警（105分贝，于雪橇扰动前250毫秒播放，持续时长40毫秒），以及有无次级任务（即短信编辑任务）。此外设置仅包含ASPS的探测试次以最小化受试者的预期效应。采用8摄像头三维运动捕捉系统采集人体运动学数据。
结果：结果显示，相较于无ASPS预警组（194 ± 46毫秒），使用ASPS预警时驾驶员手部更快移向方向盘（169 ± 55毫秒，p=0.01）；成年驾驶员在使用ASPS预警时，触碰方向盘的速度也更快（435 ± 54毫秒 vs 无预警组的470 ± 33毫秒，p=0.01）。上述效应未在青少年驾驶员群体中观察到。此外，女性驾驶员移向方向盘的速度快于男性驾驶员（166 ± 58毫秒 vs 199 ± 36毫秒，p=0.009）。
讨论：本研究结果表明，ASPS或可在校正操纵启动阶段缩短驾驶员的反应时长，且自动驾驶车辆的预警策略或许需要根据驾驶员的年龄与性别进行个性化定制。