辽宁师范大学心理学院, 大连 116029
Why does a driver can not see a critical event on the road?Interaction between “bottom-up” and “top-down” processing mechanisms
School of Psychology, Liaoning Normal University, Dalian 116029, China
收稿日期: 2018-06-24 网络出版日期: 2019-03-15
Received: 2018-06-24 Online: 2019-03-15
驾驶员“视而不见”错误是指驾驶员的视线虽然指向道路上的危险目标, 却没有知觉到其存在, 对交通安全构成威胁。本文首先在注意计算框架内, 分别从“自下而上”和“自上而下”两种加工机制探讨诱发驾驶员“视而不见”错误的主要因素, 该框架解释力不足的原因在于没有充分考虑实践经验和动机对驾驶员预期和注意定势的影响。由此提出注意计算框架扩展模型, 通过“自下而上”和“自上而下”的交互作用机制对驾驶员“视而不见”错误提出综合解释。
驾驶员“视而不见”错误是指驾驶员的视线虽然指向道路上的危险目标, 却没有知觉到其存在, 对交通安全构成威胁。本文首先在注意计算框架内, 分别从“自下而上”和“自上而下”两种加工机制探讨诱发驾驶员“视而不见”错误的主要因素, 该框架解释力不足的原因在于没有充分考虑实践经验和动机对驾驶员预期和注意定势的影响。由此提出注意计算框架扩展模型, 通过“自下而上”和“自上而下”的交互作用机制对驾驶员“视而不见”错误提出综合解释。
It causes a significant hazard to traffic safety the car drivers have been looking in the direction where the other road users were but have not perceived the presence of the other parties, which is called ‘looked-but-failed-to-see’ (LBFTS) error. This paper first analyzes the main factors which contribute to LBFTS from the perspective of both bottom-up and top-down mechanisms. That Computational Framework is not able to fully explained circumstances because of its insufficient consideration of driver’s practical experience, expectancy and attentional set. Therefore, the extended model of Computational Framework is proposed to offer comprehensive explanations to the LBFTS using bottom-up and top-down mechanisms.
It causes a significant hazard to traffic safety the car drivers have been looking in the direction where the other road users were but have not perceived the presence of the other parties, which is called ‘looked-but-failed-to-see’ (LBFTS) error. This paper first analyzes the main factors which contribute to LBFTS from the perspective of both bottom-up and top-down mechanisms. That Computational Framework is not able to fully explained circumstances because of its insufficient consideration of driver’s practical experience, expectancy and attentional set. Therefore, the extended model of Computational Framework is proposed to offer comprehensive explanations to the LBFTS using bottom-up and top-down mechanisms.
袁璐一, 常若松, 马锦飞. (2019).
YUAN Luyi, CHANG Ruosong, MA Jinfei. (2019).
在汽车与摩托车相撞事故中, 有一半可归因于汽车驾驶员没有给予摩托车手优先通行权(SWOV, 2017)。这类事故往往发生在交叉路口, 当摩托车在主干路上直行时, 支路上的汽车没有给直行的摩托车让行并与其相撞, 这被称为通行权侵犯(right of way violation) (Clarke, Ward, Bartle, & Truman, 2007; Shahar, van Loon, Clarke, & Crundall, 2012)。很多研究者对此类事故的调查结果相似：肇事驾驶员普遍声称, 他们一直在注视道路, 并且进行了所有必要的视觉搜索, 但仍然没有看到对方车辆(Clabaux et al., 2012; Clarke et al., 2007; Martens, 2017; Crundall, Clarke, Ward, & Bartle, 2008; Shahar et al., 2012)。在交通心理学文献中, 这类事故被称为“视而不见”错误(looked-but-failed-to-see error), 直译为看了却没有看见, 即驾驶员的视线虽然指向道路上的危险目标(例如, 其他道路使用者), 但是却没有知觉到其存在(Crundall, Crundall, Clarke, & Shahar, 2012; Greene, Murphy, & Januszewski, 2017; Law, Ghanbari, Hamid, Abdul-Halin, & Ng, 2016)。交通事故统计显示, 摩托车和自行车是“视而不见”错误最常见的受害者(Department for Transport, 2016)。现有数据表明, 中国摩托车保有量0.9亿辆, 自行车保有量3.7亿辆, 电动自行车1.81亿辆(新华网, “中国国际自行车展览会”, http://news. 163.com/14/0427/10/9QR49JAP00014JB5.html)。因此, 对中国道路交通安全而言, “视而不见”错误是一个潜在的巨大威胁。由此可见, 如何规避汽车驾驶员“视而不见”错误是重要而复杂的研究课题, 对于保护弱势道路使用者具有重要的现实意义。
驾驶员为什么会犯“视而不见”错误?“视而不见”本质上是注意如何影响知觉的问题(张慧, 施建农, 2014; Engström, Markkula, Victor, & Merat, 2017; Jacobsen, Ragland, & Komanoff, 2015)。Gu, Stocker和Badler (2005)在内隐和外显注意捕获研究的基础上, 认为“视而不见”错误是“自下而上”的注意捕获和“自上而下”的注意调节交互作用的结果。其中“自下而上”的注意捕获受到刺激的感觉凸显性的影响, “自上而下”注意调节受到认知凸显性、心理工作负荷、注意定势以及注意能力的影响。该注意计算框架最初是由计算机科学领域提出, 目的是以参数运算的形式量化注意机制的各个环节和影响因素, 实现虚拟人物的注意与知觉匹配的计算机程序化。对于汽车驾驶员来说, 路况复杂多变、道路危险层出不穷, 危险搜索的主观积极性和驾驶经验, 对于规避“视而不见”错误尤为重要。
感觉凸显性(sensory conspicuity, 也常称为对象凸显性, object conspicuity), 即一个刺激物自身所具有的, 能够捕获注意的某种感觉属性, 是影响“自下而上”加工机制的重要因素(Hancock, Wulf, Thom, & Fassnacht, 1990)。早在1980年, 研究者们就发现由于摩托车在大小、颜色以及与背景环境的对比度等方面的感觉凸显性比其他机动车低, 使得汽车驾驶员很难关注到他们(Thomson, 1980; Wulf, Hancock, & Rahimi, 1989), 从而增加了摩托车-汽车的碰撞事故率。因此, 早期研究者认为小型非机动车的低凸显性是诱发“视而不见”错误的主要原因(Wulf, et al., 1989)。这开创了交通心理学领域“视而不见”错误研究的先河, 先于Mack和Rock (1998)的“无意视盲”范式的提出以及Simon和Chabris (1999)的“大猩猩”实验。而无意视盲的研究也表明, 刺激的大小、颜色、位置、运动等外源性线索, 都会诱发被试对刺激“视而不见” (Fisher & Strayer, 2014; Gu et al., 2005)。
研究感觉凸显性对“视而不见”错误的影响时, 最普遍的研究范式是静态实验范式(Atchley, Tran, & Salehinejad, 2017; Kreitz, Schnuerch, Furley, & Memmert, 2018; Law et al., 2016)。研究者首先使用车载摄像机, 以驾驶员视角在十字路口或交叉路口拍摄视频, 然后从视频中截取需要的图片(例如, 摩托车距离摄像头的20m处和60m处), 使用电脑屏幕向被试呈现图片(呈现时间250~600 ms), 并让被试识别场景中是否有摩托车, 从而检测驾驶员是否发生“视而不见”错误(Briggs, Hole, & Land, 2016)。
对象亮度越高, 其感觉凸显性就越高, 观察者“视而不见”的概率也就越低。已有研究发现, 摩托车手穿着荧光制服能够减少摩托车事故的发生, 这是因为穿着亮眼的衣服能够增加摩托车的感觉凸显性, 使之能更容易捕获其他道路使用者的注意(Shahar et al., 2012)。
提升摩托车感觉凸显性的另一个直接可行的方案是打开车头灯(Beanland, Lenné, & Underwood, 2014; Cavallo et al., 2015; Mccarley, Steelman, & Horrey, 2014)。Torrez (2008)发现, 白天使用车前灯以及明亮的外壳能够使摩托车更容易被侦查到, 这可能是因为车头灯增强了摩托车与背景环境的对比度。而且车头灯的使用还可以促进驾驶员对摩托车的速度-距离判断, 提高摩托车的识别率(Koornstra, Bijleveld, & Hagenzieker, 1997)。然而, 车头灯的效果还取决于摩托车的速度、摩托车与观察者的距离以及背景环境(Hole, Tyrrell, & Langham, 1996)。Hole等人发现, 与城市环境相比, 车头灯在半乡村环境中能取得更明显的识别效果。在实施车头灯立法后, 与摩托车凸显性相关的事故的确有所减少, 摩托车手严重受伤或死亡的风险有所降低(Wells et al., 2004)。
关于提升识别率方面的研究发现, 明亮背景下, 黑色外壳的摩托车比开着车头灯的摩托车更容易被识别, 这说明摩托车配备的凸显性辅助设施的效果是否明显, 取决于背景条件(Hole et al., 1996)。
有研究者认为, 摩托车更容易被汽车驾驶员“视而不见”是由于其认知凸显性较低, 认知凸显性是指目标被观察者主动锁定的能力(Cassarino & Setti, 2016), 涉及“自上而下”的加工进程, 受到观察者的预期和经验的影响(Gibbs, Davies, & Chou, 2016; Law et al., 2016)。对于驾驶员来说, 具有高认知凸显性的目标往往是他们经验库中存储的各类危险程度较高的客体(例如大货车、油罐车等), 这类车辆更容易捕获驾驶员的注意。然而, 由于摩托车的威胁程度较低, 在道路上出现的频率不高, 因此不具有较高的认知凸显性, 更容易被驾驶员“视而不见” (Beanland, Filtness, & Jeans, 2017)。
除了明确的任务目标, 目标已知的环境概率也会引导预期的形成。Shinoda, Hayhoe和Shrivastava (2001)让被试利用模拟器在一个虚拟城镇中行驶, 利用指导语对驾驶员进行分组, 要求一半驾驶员与前车保持恒定距离, 另一半驾驶员在保持跟车距离的同时, 还要遵守交通规则。在驾驶过程中, 一个“通行”标识有时会转变成“停车”标识。这个标识或置于十字路口前, 或置于道路中央。结果发现, 驾驶员侦测标识变化的正确率很大程度上取决于他的任务目标以及标识的位置。当驾驶员的任务目标仅仅只是跟随前方汽车时, 无论标识处于道路中央还是交叉口, 被试很少侦测到标识的变化; 而当要求驾驶员跟随前车并遵守交通规则时, 被试更容易侦测到变化, 位于交叉口前的标识的侦测率要优于位于道路中央的标识的侦测率。研究认为, “对于交通信号的可见度取决于计划内的积极搜索, 计划取决于观察者的目标和已知的环境概率”。也就是说, 驾驶员的任务目标以及该目标在某一场景出现的可能性, 决定了他预期的产生, 以及他是否会在特定地点看到特定事件, 而非预期事件则很容易被“视而不见”。
有一种减少“视而不见”错误的有效改善方式是进行知觉训练。Crundall, Howard和Young (2017)采用Pelmanism知觉训练, 让被试事先做摩托车卡牌的翻牌游戏, 然后再去识别实验图片中的摩托车。结果表明, 经过知觉训练后的汽车驾驶员识别摩托车的正确率比未做知觉训练的汽车驾驶员高。研究者推测, 知觉训练能够通过增强驾驶员对摩托车的预期能力从而降低识别阈限。
Lavie (2005)的知觉理论认为, 知觉能力是有限的。知觉资源会自动处理任务相关的“高优先信息”, 其次是“低优先信息”。如果知觉资源有所剩余, 将会同时处理非任务相关信息, 直到知觉资源被消耗殆尽。驾驶任务是一个高负荷任务, 汽车驾驶员认为, 大型车辆比小型摩托车更具有危险性和威胁性。因此在驾驶过程中, 驾驶员会优先耗费大量的注意资源关注大型车辆, 剩余小部分注意资源关注小型摩托车(Law et al., 2016)。然而事实上, 摩托车等小型非机动车具有体型小、操作性高以及灵活的驾驶轨迹等特点(Crundall et al., 2012; Shahar et al., 2012), 使汽车驾驶员需要更多的注意资源去识别小型非机动车。当注意资源缺乏, 就会增加驾驶员对小型摩托车“视而不见”的概率(Greene et al., 2017; Law et al., 2016)。
尤其是在双任务条件下, 驾驶员注意资源流失得更为严重(Briggs et al., 2018)。随着汽车驾驶员手机分心研究的兴起, 研究者常用双任务范式研究驾驶员“视而不见”错误。例如, 在模拟驾驶任务中给驾驶员添加对话任务, 并要求其对道路场景中的非预期刺激(独立于驾驶场景的突兀刺激, 例如道路中间的人脸)做出反应(Bergen, Medeiros- ward, Wheeler, Drews, & Strayer, 2013)。研究结果表明, 对话任务下的驾驶员对非预期刺激的识别率要低于专心致志的驾驶员, 并且对非预期刺激的反应时更长。这是因为两个任务共享同一注意渠道并互相争夺注意资源, 导致每个任务都无法拥有充足的注意资源。同时, 在高负荷条件下, 驾驶员为了弥补注意资源的不足, 会采用习惯化的驾驶搜索图式或简捷编码, 由此也造成对非预期刺激“视而不见” (Briggs et al., 2018)。
驾驶员心理工作负荷的另一种调控方式是采取尺寸感知任务范式(Cartwright-finch & Lavie, 2007), Murphy和Greene (2015)使用该范式验证了心理工作负荷对“视而不见”错误的影响。实验要求被试在驾驶模拟场景中(一条笔直的公路, 公路两边停放着很多车辆)快速判断可否直接开车通过, 还是需要移动道路两边的车辆之后才能通过。当可通行间距极端小或极端大时, 被试可以轻易做出判断, 属于低负荷任务; 当可通行间距变得模糊, 被试很难判断能否直接通过, 属于高负荷任务。在关键试次中, 非预期刺激(人脸或行人)出现在道路一侧, 之后立即问及被试是否注意到非预期刺激, 考察知觉负荷对“视而不见”的影响。实验数据显示, 高负荷被试的反应时明显比低负荷被试的长, 判断能否通过间距的正确率也较低。这说明尺寸间距区分负荷程度是有效的。而且, 83%的高负荷被试在关键试次里没有注意到非预期刺激, 即出现“视而不见”错误, 而低负荷被试只有46%忽略了非预期刺激。
Finch和Lavie (2007)也系统地探讨了心理工作负荷对“视而不见”错误的影响。无论是通过无意视盲研究范式的变式或是通过视觉搜索范式, 他们得出了共同的结论：当前任务的心理工作负荷水平决定“视而不见”出现的概率, 当前任务的心理工作负荷越大, “视而不见”出现的概率也越高。
注意能力是指一个人同时能够注意的刺激或信息的数量(Gu et al., 2005)。注意能力受年龄差异、当时的精神状态(例如疲劳等)、认知处理(熟练化)以及生理状态(药物和酒精)的影响(Ward & Scholl, 2015)。一些研究表明饮酒会增加“视而不见”错误：中度饮酒的被试注意能力受损, 更加容易出现“视而不见”错误(Shiferaw, Stough, & Downey, 2014; Harvey, Bayless, & Hyams, 2018)。在驾驶背景中, 研究者们通过Rensink闪烁范式考察年轻和老年驾驶员对场景变化“视而不见”的差异。被试以驾驶员视角观看成对的驾驶场景照片, 并尽快识别两者之间的差别。研究表明, 在侦测变化方面, 老年驾驶员比年轻驾驶员的识别准确率更低, 反应时更长(Pringle, Irwin, Kramer, & Atchley, 2001)。而且注意广度发挥了重要作用：注意广度更大的人识别变化更快。众所周知, 功能性视野随着年龄逐渐狭窄, 这可能导致老年驾驶员在识别场景变化方面表现更差(Heenan, Herdman, Brown, & Robert, 2014)。
诸多事实表明, 即使汽车驾驶员处于充足的注意资源条件下, 仍有可能出现“视而不见”错误 (Craen et al., 2014; Strayer & Fisher, 2015)。因此, 研究者引入注意定势效应来解释这个现象(Beanland, et al., 2017; Borowsky, Shinar, & Parmet, 2008; Briggs et al., 2018; Pammer & Blink, 2013; Pammer, Bairnsfather, Burns, & Hellsing, 2015)。注意定势, 即个体对目标刺激的相关特征所产生的预期或准备状态(张慧, 施建农, 2014)。或者说它是一种寻找任务相关的场景信息而忽略任务不相关信息的一种偏见(Briggs et al., 2018)。当刺激和刺激特征符合预期时, 便会诱发注意定势(张慧, 施建农, 2014)。例如, Most和Astur (2007)通过驾驶模拟器诱发驾驶员的注意定势。他们要求被试在路口跟随路标(黄色或蓝色箭头)的指示通行。在第十个交叉路口, 一辆黄色或蓝色的摩托车出乎意料地转入驾驶员车辆的行驶路线, 然后停下来。驾驶员必须对此事件作出反应, 以避免碰撞。当摩托车的颜色与驾驶员的注意定势不一致时, 制动潜伏期比一致情况下长186 ms。另外, 在不一致条件下, 36%的驾驶员与摩托车发生碰撞, 而在一致状态下只有7%。他们认为, 这表明注意定势可能会降低个体的情景意识, 尤其会导致经验驾驶员在面对意外刺激时出现“视而不见”错误, 进而恶化交通状况。
注意计算框架主要从计算机程序运算的角度, 探讨知觉匹配过程, 分析了内部驱动的“自上而下”的设置和外部驱动的“自下而上”的输入的协同机制。具体来说, “自下而上”机制通过场景中对象的“凸显性” (感觉凸显性特征)来过滤感觉信息并计算出客观凸显性地图。颜色、对比度和运动等主要的视觉特征都会由这个过滤器过滤。同时, “自上而下”加工过程中的预期和认知凸显性模块, 决定注意定势在视觉搜素中的功能。注意定势是记忆中维护任务突出属性的主观特征储藏池。如果客观凸显性地图不能和观察者的主观特征储藏池相匹配的话, 就会诱发“视而不见”错误。
Gu等人的初衷是想把每个影响因素当成可量化的变量, 并通过计算框架, 输入每个变量的特定参数计算观察者“视而不见”的概率, 但是实验结果并不乐观。究其原因, 是因为注意计算框架仍把人看做独立的计算机, 而没有将人看做是社会实践经验和个人主观能动性交互作用的产物, 也没有考虑到个体知觉匹配过程中信息编码的独特性和有限性。Crundall等人(2008)提出的汽车-摩托车碰撞解释框架认为, 驾驶图式是驾驶员注意搜索策略和危险知觉的关键影响因素。本研究以注意计算框架为主体, 结合汽车-摩托车碰撞解释框架的驾驶图式概念, 并辅以新近研究中的驾驶员动机变量及驾驶员编码特征(Crundall et al., 2008; Sänger & Wascher, 2011; Craen et al., 2014), 形成注意计算框架扩展模型, 通过“自下而上”和“自上而下”的交互作用机制来解释“视而不见”错误, 见图1 (虚线模块为本研究新增变量)。
在原有的注意计算框架中, 个体预期由任务相关特征激活, 由此形成注意定势并识别目标刺激。但是, 任务相关特征能够直接激活个体预期吗?大量关于驾驶员危险知觉的研究表明, 新手驾驶员和经验驾驶员面对相同的危险识别任务, 反应时和识别率表现出显著差异, 究其原因, 驾驶经验图式在其中起到了指导作用(Agrawal, Knodler, Fisher, & Samuel, 2017; Chan, Pradhan, Pollatsek, Knodler, & Fisher, 2010; Fisher, Pradhan, Pollatsek, & Jr Knodler, 2007)。而注意计算框架恰恰忽略了个体间经验图式的差异。Crundall等人(2008)认为, 对驾驶行为最直接的影响来自驾驶图式, 驾驶图式是指导驾驶员在给定环境中, 应该观察哪里、预期什么、并以此做出行为决策的行动准则或模板。Crundall等人还提出, 图式既包含普遍的规则(如定期观察左右车镜, 水平扫描等), 也表征特定概念、事物或事件的认知结构, 影响对相关信息的加工过程。对于具体的交通事件, 驾驶员会形成具体的子图式, 例如, 当驾驶员行驶到陌生的环岛路口时, 特定的路况特征会激活经验积累的关于环岛通行规则的驾驶图式, 帮助驾驶员顺利通过。结合Crundall等人的这一观点, 在原有注意计算框架中的任务特征和预期之间, 研究者应考虑新增驾驶图式变量, 由此可以提出新的假设：特定驾驶任务的相关特征, 能够激活特定驾驶图式, 并以预期为中介变量影响视觉搜索行为。
当汽车驾驶员与某类道路使用者互动机会较少时, 将无法充分发展恰当的互动经验图式, 这将增加汽车驾驶员对非预期目标“视而不见”的可能性。有效的改善方式是, 随着驾驶里程的增长, 不断丰富和完善驾驶图式(Crundall et al., 2012)。换句话说, 驾驶员只有通过在不同的环境中反复接触同类情境, 提取抽象规则, 形成一般化或特殊化的驾驶图式, 才能够形成特定的危险预期, 为一般视觉搜索策略提供指导(Land & Furneaux, 1997)。Fisher等人发现, 随着驾驶图式的累积和完善, 驾驶员提升了危险预期能力, 能够快速定位潜在危险事件(引自Crundall et al., 2008)。
跨文化研究也发现, 地方交通文化特点会潜移默化地影响当地驾驶员, 形成特色驾驶图式。Lee, Sheppard和Crundall (2015)假设, 居住在摩托车密集地区的驾驶员, 不管他有没有驾驶摩托车的经验, 都应该能更好地检测行驶过程中遇到的摩托车。于是, Lee等人比较了马来西亚驾驶员和英国驾驶员感知不同距离(远、中、近)接近车辆(摩托车和汽车)的能力(在马来西亚, 摩托车非常常见, 而英国正好相反)。实验结果表明, 马来西亚驾驶员和英国驾驶员在总体上感知接近车辆的能力没有差异, 但是马来西亚驾驶员感知远距离摩托车的能力要优于英国驾驶员。说明驾驶图式对驾驶员的远距离预期能力起到了积极影响。
驾驶图式虽然能够提升驾驶员的预期能力, 但是在非预期事件中, 固化的驾驶图式可能会带来先入为主的成见, 产生消极的注意定势效应。Langham, Hole, Edwards和O’Neil (2002)设计了一个实验, 他们让被试看一系列以驾驶员为视角的视频, 并在识别危险(危险具有未知性)后尽快按键。在其中一个片段中, 有一辆闪灯的警车停在路中。视频画面逐渐靠近路中的警车, 这在现实生活中是一种很危险的情况, 需要驾驶员改变车道避免碰撞。给一半驾驶员呈现该警车在行车方向上, 笔直地停在路中(就像此车已经抛锚); 给另一半驾驶员呈现警车以45度角停在路中。在这个实验中, 驾驶员对于同向停靠的警车比成角度停靠的警车反应更慢。在后续实验中, 当要求驾驶员同时进行接打手机任务时, 这种效应更加显著。视频是在晴朗的白天拍摄的, 而且警车两侧和后面都有不同寻常的反射光条, 并在上方有蓝红闪灯, 因此这些车辆从外观上看十分显著, 很难用知觉局限来解释这些事故。Langham等人认为, 车辆在道路中间抱死是一种非预期事件, 如果驾驶员看见前方有一辆车, 会先入为主地假定它与自己同方向前进, 唯一能驳倒这种假定的线索是, 静止的车辆在视网膜上的成像半径会逐渐增大, 但是当这种线索被注意到时, 碰撞已经不可避免。而呈45度角方向抱死的车辆, 之所以能够快速引发驾驶员注意, 是因为这种场景与预期不符, 可以打破图式。这一研究表明, 驾驶图式越固化, 驾驶员越容易忽视非预期事件。
除了这种固化的驾驶图式, 还有关于道路标志位置和行驶路线的固化驾驶图式也会诱发驾驶员的“视而不见”效应。Borowsky等人(2008)向经验驾驶员和新手驾驶员展示典型的道路标志(例如, 禁止右转), 路标分别放在道路的右侧(正常情况)和左侧(意外情况)。经验驾驶员更容易习惯性探测道路右侧, 而忽视左侧路标, 新手驾驶员则不受路标位置的影响。Charlton和Starkey (2013)做了一个跟踪实验, 他们让被试在驾驶模拟器里沿着一条固定的路线定期驾驶三个月。在20节课程中收集了一系列的测量指标, 包括刺激检测率和驾驶绩效。数据显示, 随着时间的推移, 累积的驾驶经验使驾驶员“视而不见”错误的频率有所提高, 而且驾驶员最有可能在离自己家很近的地方卷入意外危险。未来研究者可以继续深入挖掘驾驶员还有哪些固化的驾驶图式, 并结合各类道路非预期事件, 将极大地拓展驾驶员“视而不见”研究。
以往有关注意定势的研究主要集中在刺激的局部特征方面。随着研究的深入, 对象之间的语义联系成为注意定势研究的焦点问题。语义一致性定势效应, 即人们对具有一致语义特征的对象、情景或行为产生心理模板的认识(Pammer & Blink, 2013)。Pammer和Blink让被试在城市或者乡村环境中识别非预期刺激(行人和动物)。通过识别的正确率和反应时来研究背景环境和非预期刺激的一致性是否影响“视而不见”错误的发生。结果证明, 在城市环境下, 被试更容易发现行人, 而在乡村环境下, 被试更容易发现动物。因为被试显而易见的认为城市环境和行人是一致的, 而乡村环境和动物是一致的。
这一研究的创新在于, 研究者仅仅是通过指导语将驾驶环境信息告知被试, 便能诱发特有的注意定势模式, 由此超越了刺激简单特征, 在“自上而下”的高级意义加工过程中探索注意定势效应, 发展成语义模式下概念信息的定势理论。虽然, 注意定势在某种程度会加大“视而不见”或无意视盲出现的概率, 但是也能减轻人们的心理工作负荷, 提升搜索效率。以往研究中对于语义一致性定势的消极效应研究较多, 未来研究者可以进一步考察其积极效应。
驾驶图式在驾驶经验累积过程中不断完善, 因此, 研究者大多通过划分驾驶经验类型评估驾驶图式。驾驶经验有两个划分维度：驾驶时间和驾驶车辆类型(Costa et al., 2014)。Borowsky等人(2008)根据驾驶时间长短将驾驶员划分为新手驾驶员(驾驶时间至多5个月)和经验驾驶员(驾驶时间至少5年)。Crundall等人(2008)根据驾驶车辆类型将驾驶员划分为汽车驾驶员(只驾驶过汽车)和双重经验驾驶员(dual-driver, 既驾驶过汽车, 也驾驶过摩托车)。研究者通常让具有不同经验的驾驶员进行静态范式实验, 探究经验以及经验和其他因素的交互作用对“视而不见”错误的影响(Crundall et al., 2017)。
Crundall等人(2008)使用问卷调查发现, 汽车驾驶员和双重经验驾驶员对摩托车手的态度和信念不同, 这可能导致汽车驾驶员缺乏一个心理模型指导他们与摩托车手互动。对同理心态度的分析显示, 双重经验驾驶员对寻找摩托车手的必要性有更深的了解, 这可能是因为他们对摩托车手面临的危险和困难有直接的经验。
受到问卷调查结果的启发, Crundall (2017)等人采用静态实验范式发现, 与检测摩托车相比, 双重经验驾驶员和汽车驾驶员都对汽车的检测率较高, 反应时较快。但是双重经验驾驶员识别远距离摩托车的正确率要高于汽车驾驶员, 且反应时更快。研究者推测, 双重经验驾驶员因为拥有更丰富的驾驶图式, 有效避免了摩托车“视而不见”错误。
以上研究充分说明, 驾驶经验能否减少“视而不见”错误, 并不取决于单一驾驶经验累积时间的长短。即使驾驶经验累积时间很长, 但是如果经验系统中仅有一种特定图式, 并不利于形成合理预期和搜索策略的选择; “视而不见”错误的减少, 更依赖于经验系统中驾驶图式的丰富性和多样性, 多样的图式能够帮助驾驶员在各种驾驶情境中, 甄别“非典型”事件, 从而增加对偶然事件或非常规事件的预期能力。
在驾驶过程中, 由于车速较快, 交通环境复杂多变, 驾驶员无法对环境信息进行精细编码, 简捷编码(shorthand codes)便成为一种有效的替代编码方式, 这种方式通过积累经验逐渐自动化(Langham, 1999)。简捷编码是一种相对简单的知觉组织形式, 驾驶员习惯性地将目标刺激的某个知觉属性与特定的驾驶环境相联系, 并作为行动依据(Parthemore & Morse, 2010)。Hole等人(1996)最先证明了驾驶员的这种简捷编码方式, 他们让被试以驾驶员等候并道的视角, 观看一系列交通场景幻灯片。首先, 要求他们反复观看使用车头灯的摩托车照片, 再让他们在众多图片里搜寻摩托车。结果发现, 驾驶员在识别没开车头灯的摩托车时反应明显较慢, 有的驾驶员甚至视而不见。这意味着驾驶员们正在寻找车头灯而不是摩托车。被试过于依靠车头灯(尤其在远距离)来识别摩托车, 实际上是以忽视摩托车非典型线索为代价, 提升侦测摩托车典型线索的效率, 由此可以推测一种普遍现象：车头灯成为摩托车的简捷编码线索, 驾驶员对这种线索的预期产生了知觉定势。
在注意计算框架中, 个体的注意捕获依赖外部“自下而上”的刺激输入和内部“自上而下”加工的合作。感觉凸显性以“自下而上”的方式进行加工, 而认知凸显性、心理工作负荷、预期和注意能力则属于“自上而下”的加工系统。当道路信息输入后, 外界刺激的感觉凸显性(如颜色、对比度)“自下而上”驱动外源性注意捕获机制, 对感觉信息进行过滤。与此同时, 经验系统“自上而下”对信息进行匹配和整体理解, 并引导选择性注意。对于当前特定的搜索任务, 搜索的重点对象往往是具有高认知凸显性的事物。例如, 在驾驶员道路危险搜索任务中, 具有高认知凸显性的刺激是那些对驾驶员而言具有高危险意义的客体, 例如大型车辆、行人等。
除了搜索目标本身的感知凸显性, 任务相关特征也决定着搜索效率。例如, 相同特征的驾驶任务对不同驾驶经验的驾驶员的主观难度是不同的, 驾驶任务主观难度越大、驾驶持续时间越长, 驾驶员的心理工作负荷就会越大, 导致搜索效率越低。如果心理工作负荷超载或负荷不足, 将引发驾驶员主动疲劳或被动疲劳; 如果负荷适中, 驾驶员将适应驾驶任务。反之, 个体的疲劳状态也会反作用心理工作负荷。例如, 相同的任务, 对疲劳驾驶员来说, 将变得负荷超载。驾驶员的疲劳或适应状态直接影响其注意能力, 当注意能力不足, 驾驶员无法充分完成感觉信息的编码和知觉匹配, 增加“视而不见”错误的可能性; 但即使有充足的注意资源, “视而不见”错误依然可能会因注意定势而发生。
在原有的注意计算框架中, 任务相关特征以预期为中介变量, 影响注意定势。但是, 任务相关特征仅涉及到任务本身的客观特点(如, 两地之间的客观距离、环岛路口的法定行驶方式等), 而预期则是个体根据自身知识背景和以往经验所产生的对未来情况的估计。由此可见, 任务相关特征不能直接引发特定预期, 而必须以知识背景或经验为中介变量。驾驶员如果想要完成特定任务(例如通过环岛路口), 必须依赖以往经验积累的图式来预期环境变化, 控制行为。因此, 在原有模型中我们新增了驾驶图式变量, 作为特定驾驶任务影响预期的中介变量, 对预期产生激活作用。新近的研究表明, 被激活的预期, 其活跃性受到驾驶员动机的调节, 因此我们加入动机因素, 作为预期的调节变量。预期是对未来情况的估计, 这种先入为主的假定倾向使个体产生一种注意准备状态, 即注意定势。在常规情况下, 注意定势可以让驾驶员在复杂的驾驶环境中进行简捷编码, 提高注意能力和知觉匹配效率; 但是, 在非常规情况下, 注意定势会让驾驶员忽视非预期刺激或错误编码, 诱发“视而不见”错误的产生(Langham, et al., 2002; Parthemore & Morse, 2010)。
目前, 静态范式是驾驶员“视而不见”研究的主流范式, 静态范式的优点是：可以严格控制实验条件, 并对许多变量(刺激类型、大小、颜色、出现位置等)进行操控。但是存在如下问题：首先, 静态范式是在封闭实验室里采用电脑呈现图片的方法让被试识别非预期刺激, 然而图片显示的只是一瞬间(150~600 ms)的驾驶场景, 无法让被试根据已有的背景环境信息做出合理的判断。而且, 图片材料不能反映刺激的变化对“视而不见”的影响(即, 变化视盲), 这并不符合真实驾驶情境; 第二, 由于沿途环境的变换, 非预期刺激与背景环境的对比也会发生改变, 静止的图片材料只能提供单一背景, 可能会模糊这一影响因素。例如, 某些摩托车凸显性改善措施(车身亮度)在静态范式中可能有效, 但是由于驾驶环境的不断变化, 在动态视频中这种效果可能会被抵消或减少(高亮车身在明亮背景中可能会变得不如在阴暗背景中明显); 第三, 之前的实验往往让被试带着明确的目标(即检测预期刺激或事件), 观看图片并做出识别反应。这种实验范式虽然强调了被试对非预期刺激的识别, 但是在真实驾驶情境中, 驾驶员还需要制动或转向操作, 这无疑降低了实验难度, 无法完全反映被试在实际驾驶情景中的心理工作负荷和认知操作过程。综上, “视而不见”错误的静态实验范式的外部效度有待商榷, 相关研究结果应该谨慎对待。
因此, 为了获得更准确的研究结果, 未来的研究有必要改进实验方法, 使用更真实、被试能够主动控制的驾驶模拟器或道路真实任务来重复这些实验(真实的驾驶活动包括改变路线、在规定时间内驾驶到目的地等)。眼动测量可以成为验证这一假设的强力手段。研究者根据驾驶员的眼动轨迹和视觉搜索模式可以进一步了解, 为什么驾驶员会侦测不到非预期的驾驶相关事件。同时, 眼动测量法还可以结合驾驶模拟器研究, 采用改变路线、时间压力等模拟驾驶任务, 对“视而不见”的危险知觉机制进行全面考察, 而不仅仅只是搜集驾驶员对静态图片刺激或单一道路事件的反应时数据。通过动态场景研究, 还可以进一步分析驾驶员在哪个驾驶时间段更容易出现“视而不见”错误, 从而丰富驾驶警觉和驾驶分心研究。
除此之外, 未来研究者还可以采用危险知觉研究的动态范式, 将非预期刺激的感知凸显性和位置因素融入道路情境中, 与道路危险意义相结合。例如, 播放道路场景视频, 在危险刺激完全暴露之前, 暂停视频播放, 让被试根据已有的情境知觉, 预测下一刻可能会发生什么情况(Ciceri & Ruscio, 2014)。或者在视频结束后, 让被试阐明在此情境中, 他们的安全关注点在什么地方(例如, 速度调节还是车道维持等)。按照负荷理论, 比起执行单任务的驾驶员, 双任务条件下, 心理负荷超载的驾驶员可能会更多地依赖已有的图式框架进行预期, 由此更容易诱发注意定势, 这将方便研究者更加直接地将驾驶员的基本图式框架提取出来, 对驾驶员注意计算框架进行验证和完善。
如果驾驶员“视而不见”研究方法的生态效度问题得以解决, 将激发对驾驶员“视而不见”错误本质的新探索, 使该模型进一步丰富和完善。
第一, 在“自下而上”的加工系统里, 除了现有的对于大小、颜色、对比度等感觉凸显性的研究之外, 非预期事物的运动轨迹也是需要考察的重点。例如, 有规律的运动轨迹和无规律的运动轨迹相比, 哪种条件更容易诱发驾驶员的“视而不见”?突兀夸张的动作一定能避免“视而不见”吗?而且, 从“自下而上”的角度来看, 非预期刺激的凸显性和位置是影响驾驶员反应速率的重要变量。而在以往的实验中, 这两个变量往往没有进行独立考察, 而是被整合成一个单一因素。如果能够将这两个因素分离, 并在动态范式中考察交互作用, 可能会出现不同的结果。
第二, 在“自上而下”的加工系统里, 是否还有尚未发现的诱导驾驶员发生“视而不见”错误的因素?例如, 如果假设双任务会加大注意定势对危险知觉的影响程度, 那么考察个体情境意识持续刷新能力的个体差异所起的调节作用将非常有理论和实践意义, 而这一问题可以以测量个体的工作记忆能力为切入点。此外, 负荷理论认为, “熟练化”操作会降低被试的心理工作负荷, 从而剩余更多的注意资源察觉意外刺激。然而Charlton和Starkey (2013)的实验却表明驾驶员在熟悉环境中更容易发生“视而不见”。之所以得出相反的结论, 是因为驾驶员的“熟练化”依赖本人的驾驶经验, 而以往的实验混淆了对驾驶经验类型的定义。我们认为, 驾驶经验不能仅依靠驾驶里程和驾驶年龄进行简单划分, 还应该考量驾驶经验的丰富性和多样性。例如, 在固定路线(家和工作地点之间)驾驶越久的驾驶员, 反而会产生消极的注意定势(Charlton & Starkey, 2013); 而多样化驾驶环境或许更有利于积极注意定势的产生。未来研究者如果要验证这一假设, 需要构建一个“驾驶员经验体系”, 系统而详细地划分经验类型。例如：简单或复杂路况的驾驶里程或驾龄, 长途汽车驾驶员和私家车汽车驾驶员, 山城汽车驾驶员和平原汽车驾驶员等, 以便对“经验”这个自变量进行明确操作。这样才能更有针对性地考察驾驶员在何种情境下, 对何种意外事件更容易“视而不见”。
如果驾驶员注意计算框架扩展模型能够得到充分验证和完善, 将为驾驶员“视而不见”错误的改善策略提供科学依据。例如, 如果充分验证分心任务会加重注意定势的消极影响, 那么对分心驾驶员进行教育将具有重要的实践意义。应该让驾驶员了解, 即使在不分心的情况下, 他们的注意分配策略也会受到定势的左右。而在进行分心任务时, 由于注意资源不足, 注意定势对危险知觉和关键驾驶事件应激反应的消极损害将更加明显。未来研究者可以从两个方面完善危险知觉测试以提高驾驶员的安全意识, 避免“视而不见”错误。第一, 在驾校测试中增加非预期危险事件, 提高驾驶员对危险突发事件的预期能力, 抵消注意定势的消极影响; 第二, 对驾驶员进行危险知觉评价训练, 例如, 让驾驶员判断当前驾驶情境是否危险并评判危险等级, 并给予经验驾驶员的视听反馈; 或让受训驾驶员完成Pelmanism任务(一种匹配易受伤道路使用者的翻牌游戏), 提高他们对易受伤道路使用者的敏感性, 促进注意定势的积极影响, 从而训练驾驶员在特定驾驶场景中合理的分配注意资源。
同时, 未来研究者还可以考虑如何将已有的理论成果应用于道路信息标识的方案设置。例如, 许多电子高架道路标志经常滚动提示“前方堵塞”或“安全带挽救生命”等安全信息, 这些道路标识是否会影响驾驶员的预期和注意定势?如何呈现才能更有效地提高驾驶员对路标信息的获取效率?这些问题的探索对改善道路安全意义重大。
在日常生活中, “视而不见”错误看似无足轻重, 并且发生的概率很小。然而海因希里法则(Jehring, 1931)指出: 每一起严重事故的背后, 必然有29次轻微事故和300起未遂先兆以及1000起事故隐患。这说明, 在安全生产生活中, 任何一点小概率事件都会造成重大损失。驾驶员“视而不见”错误研究的兴起, 为工程心理学其他领域的研究者打开了一扇窗口, 其范式和理论框架可以广泛拓展到其他安全生产领域问题, 对各行业安全文化的构建具有重要的实践意义。
Inattentional blindness refers to that observers cannot detect some stimuli even if the stimuli stand exactly where their gaze falls. This phenomenon is common among our daily life and contributes to many traffic and medical accidents. We reviewed the papers and found that “limited resource” and “attentional set” take accounts to this phenomenon. In general, the two causes contribute to this phenomenon simultaneously. However, “attentional set” will lead to this phenomenon independent of “limited resource”. More in depth, from the aspect of neuro-mechanism, “limited resource” and “attentional set” acted on the middle stage of brain processing. The unexpected stimuli have ever received some conscious processing in the traditional conscious processing region even when they are not been aware of. The conscious inputs in occipital-parietal areas in the middle stage, the activation level of temporo-parietal junction and intraparietal sulcus determine whether the unexpected stimuli can arrive to conscious level.
Advanced virtual reality based training to improve young drivers' latent hazard anticipation ability
Constructing a publically available distracted driving database and research tool,
BACKGROUND: The goal of the current work was to create a publicly available visualization tool of distracted driving research, the purpose of which is to allow the public and other stakeholders to empirically inform questions of their choice that may bear on policy discussions. METHODS: Fifty years of distracted driving research was used to design a comprehensive database of studies that evaluated the effects of distraction on driving performance. Distraction sources (e.g., texting, talking, visual distraction) and performance measures were defined, and the sample of studies were evaluated and categorized by their measures. RESULTS: The final product yielded 342 studies using various methodologies. Across all measures, 1297 found distractions degraded driving performance, 54 found distraction improved driving performance, and 257 found distraction had no effect on driving performance. An analysis of the most common phone distractions (texting and talking) showed that texting almost always results in degraded performance. Aggregate data reveal no difference in performance decrements for hand-held or hands-free phones even though single studies of those variables vary in their outcomes. CONCLUSIONS: This project illustrates how scientific research can be made publically available for use by a diverse audience of stakeholders. An important result of this project is that data aggregated along a simple set of characteristics such as whether or not performance is decreased, improved or not affected, can reveal trends in the data that are less clear from any individual study.Copyright 2016 Elsevier Ltd. All rights reserved.
Change detection in urban and rural driving scenes: Effects of target type and safety relevance on change blindness,
The ability to detect changes is crucial for safe driving. Previous research has demonstrated that drivers often experience change blindness, which refers to failed or delayed change detection. The current study explored how susceptibility to change blindness varies as a function of the driving environment, type of object changed, and safety relevance of the change. Twenty-six fully-licenced drivers completed a driving-related change detection task. Changes occurred to seven target objects (road signs, cars, motorcycles, traffic lights, pedestrians, animals, or roadside trees) across two environments (urban or rural). The contextual safety relevance of the change was systematically manipulated within each object category, ranging from high safety relevance (i.e., requiring a response by the driver) to low safety relevance (i.e., requiring no response). When viewing rural scenes, compared with urban scenes, participants were significantly faster and more accurate at detecting changes, and were less susceptible to ooked-but-failed-to-see errors. Interestingly, safety relevance of the change differentially affected performance in urban and rural environments. In urban scenes, participants were more efficient at detecting changes with higher safety relevance, whereas in rural scenes the effect of safety relevance has marginal to no effect on change detection. Finally, even after accounting for safety relevance, change blindness varied significantly between target types. Overall the results suggest that drivers are less susceptible to change blindness for objects that are likely to change or move (e.g., traffic lights vs. road signs), and for moving objects that pose greater danger (e.g., wild animals vs. pedestrians).
Psychological factors in seeing motorcyclesIn L. Rößger, M. G. Lenné, & G. Underwood (Eds.), ( pp.
Safety in numbers: Target prevalence affects the detection of vehicles during simulated driving,
The crosstalk hypothesis: Why language interferes with driving,
Performing two cognitive tasks at the same time can degrade performance for either domain-general reasons (e.g., both tasks require attention) or domain-specific reasons (e.g., both tasks require visual working memory). We tested predictions of these two accounts of interference on the task of driving while using language, a naturally occurring dual task. Using language and driving a vehicle use different perceptual and motor skills. As a consequence, a domain-general explanation for interference in this dual task appears most plausible. However, recent evidence from the language processing literature suggests that when people use language with motor content (e.g., language about actions) or visual content (e.g., language about visible objects and events), they engage their motor and perceptual systems in ways specifically reflecting the actions and percepts that the language is about. This raises the possibility that language might interfere with driving for domain-specific reasons when the language has visual or motor content. To test this, we had participants drive a simulated vehicle while simultaneously answering true false statements that had motor, visual, or abstract content. A domain-general explanation for interference would predict greater distraction in each of these three conditions compared with control, while a domain-specific explanation would predict greater interference in the motor and visual conditions. Both of these predictions were borne out but on different measures of distraction, suggesting that language-driven distraction during driving and dual tasks involving language in general may be the result not only of domain-general causes but also specific interference caused by linguistic content.
The relation between driving experience and recognition of road signs relative to their locations,
Objectives: Examine how driving experience and expectations affect the ability of experienced drivers to identify traffic signs - specifically, no right turn (NRT) and no left turn (NLT) at intersections. Background: Failure to heed signs is a frequent cause of accidents, and the authors focused on the contributions of experience and expectancy to sign identification. Method: Inexperienced and experienced drivers were connected to an eye tracker system and briefly exposed to various traffic scenes. Some of the pictures included an NRT sign at the expected location (on the right), and some included the same sign at an unexpected location (on the left). The same procedure was used with an NLT traffic sign. Results: Experienced drivers identified traffic signs better than inexperienced drivers did when the signs were posted at the expected location but identified them worse than did inexperienced drivers when they were at unexpected locations. Conclusions: With experience, drivers' expectations regarding the expected location of traffic signs become so strong that violating these expectancies results in more identification errors among experienced drivers than among inexperienced drivers. To optimize experienced drivers' traffic sign identification, signs must be located in accordance with drivers' expectations - specifically, on the right side of the road. Applications: When signs are misplaced, crashes can be caused by inappropriate placement rather than inappropriate driving. Highway designers should ensure that their design conforms to standards that shape experienced drivers' expectations.
The impact of attentional set and situation awareness on dual tasking driving performance,
Imagery-inducing distraction leads to cognitive tunnelling and deteriorated driving performance,
The effects of imagery-induced distraction on hazard perception and eye movements were investigated in 2 simulated driving experiments. Experiment 1: sixty participants viewed and responded to 2 driving films containing hazards. Group 1 completed the task without distraction; group 2 completed a concurrent imagery inducing telephone task; group 3 completed a non imagery inducing telephone task. Experiment 2: eye-tracking data were collected from forty-six participants while they reacted to hazards presented in 16 films of driving scenes. 8 films contained hazards presented in either central or peripheral vision and 8 contained no hazards. Half of the participants performed a concurrent imagery-inducing task. Compared to undistracted participants, dual-taskers were slower to respond to hazards; detected fewer hazards; committed more “looked but failed to see” errors; and demonstrated “visual tunnelling”. Telephone conversations may interfere with driving performance because the two tasks compete for similar processing resources, due to the imagery-evoking aspects of phone use.
The role of perceptual load in inattentional blindness,
Perceptual load theory offers a resolution to the long-standing early vs. late selection debate over whether task-irrelevant stimuli are perceived, suggesting that irrelevant perception depends upon the perceptual load of task-relevant processing. However, previous evidence for this theory has relied on RTs and neuroimaging. Here we tested the effects of load on conscious perception using the “inattentional blindness” paradigm. As predicted by load theory, awareness of a task-irrelevant stimulus was significantly reduced by higher perceptual load (with increased numbers of search items, or a harder discrimination vs. detection task). These results demonstrate that conscious perception of task-irrelevant stimuli critically depends upon the level of task-relevant perceptual load rather than intentions or expectations, thus enhancing the resolution to the early vs. late selection debate offered by the perceptual load theory.
Complexity as key to designing cognitive-friendly environments for older people,
The lived environment is the arena where our cognitive skills, preferences, and attitudes come together to determine our ability to interact with the world. The mechanisms through which lived environments can benefit cognitive health in older age are yet to be fully understood. The existing literature suggests that environments which are perceived as stimulating, usable and aesthetically appealing can improve or facilitate cognitive performance both in young and older age. Importantly, optimal stimulation for cognition seems to depend on experiencing sufficiently stimulating environments while not too challenging. Environmental complexity is an important contributor to determining whether an environment provides such an optimal stimulation. The present paper reviews a selection of studies which have explored complexity in relation to perceptual load, environmental preference and perceived usability to propose a framework which explores direct and indirect environmental influences on cognition, and to understand these influences in relation to aging processes. We identify ways to define complexity at different environmental scales, going from micro low-level perceptual features of scenes, to design qualities of proximal environments (e.g., streets, neighborhoods), to broad geographical areas (i.e., natural vs. urban environments). We propose that studying complexity at these different scales will provide new insight into the design of cognitive-friendly environments.
Improving car drivers' perception of motorcycle motion through innovative headlight configurations
The most frequent cause of motorcycle accidents occurs when another vehicle violates the motorcycle’s right-of-way at an intersection. In addition to detection errors, misperception of the approaching motorcycle’s speed and time-to-arrival is another driver error that accounts for these accidents, although this error has been studied less often. Such misperceptions have been shown to be related to the small size of motorcycles and to their small angular velocity when approaching. In two experiments we tested the impact of different motorcycle headlight configurations in various ambient lighting conditions (daytime, dusk, and nighttime). The participants drove on a driving simulator and had to turn left across a line of vehicles composed of motorcycles and cars. The motorcycles were approaching at different speeds and were equipped with either a “standard” headlight, a “horizontal” configuration (added to the standard headlight were two lights on the rearview mirrors so as to visually increase the horizontal dimension of the motorcycle), a “vertical” configuration (one light on the rider’s helmet and two lights on the fork were added to the standard headlight so as to increase the vertical dimension of the motorcycle), or a “combined” configuration (combining the horizontal and vertical configurations). The findings of the first experiment in nighttime conditions indicated that both the vertical and combined configurations significantly increased the gap car drivers accepted with respect to the motorcycle as compared to the standard configuration, and that the accepted gaps did not differ significantly from those accepted for cars. The advantage of the vertical and combined configurations showed up especially when the motorcycle’s approach speed was high. The findings of the second experiment in dusk and daytime conditions indicated similar patterns, but the headlight-configuration effect was less pronounced at dusk, and nonsignificant during the day. The results are discussed with regards to possible applications for motorcycles.
Are driving simulators effective tools for evaluating novice drivers’ hazard anticipation, speed management, and attention maintenance skills,
Novice drivers (teen drivers with their solo license for 6 months or less) are at a greatly inflated risk of crashing. Post hoc analyses of police accident reports indicate that novice drivers fail to anticipate hazards, manage their speed, and maintain attention. These skills are much too broadly defined to be of much help in training. Recently, however, driving simulators have been used to identify those skills which differentiate the novice drivers from older, more experienced drivers in the areas of hazard anticipation and speed management. Below, we report an experiment on a driving simulator which compares novice and experienced drivers performance in the third area believed to contribute especially heavily to crashes among novice drivers: attention to the forward roadway. The results indicate that novice drivers are much more willing to glance for long periods of time inside the vehicle than are experienced drivers. Interestingly, the results also indicate that both novice and experienced drivers spend equal amounts of time glancing at tasks external to the vehicle and in the periphery. Moreover, just as a program has been designed to train the scanning skills that clearly differentiate novice from experienced drivers, one might hope that a training program could be designed to improve the attention maintenance skills of novice drivers. We report on the initial piloting of just such a training program. Finally, we address a question that has long been debated in the literature: Do the results from driving simulators generalize to the real world? We argue that in the case of hazard anticipation, speed management, and attention maintenance the answer is yes.
Driving on familiar roads: Automaticity and inattention blindness,
This paper describes our research into the processes that govern driver attention and behavior in familiar, well-practiced situations. The experiment examined the effects of extended practice on inattention blindness and detection of changes to the driving environment in a high-fidelity driving simulator. Participants were paid to drive a simulated road regularly over 3 months of testing. A range of measures, including detection task performance and driving performance, were collected over the course of 20 sessions. Performance from a yoked Control Group who experienced the same road scenarios in a single session was also measured. The data showed changes in what drivers reported noticing indicative of inattention blindness, and declining ratings of mental demand suggesting that many participants were "driving without awareness". Extended practice also resulted in increased sensitivity for detecting changes to road features associated with vehicle guidance and improved performance on an embedded vehicle detection task (detection of a specific vehicle type). The data provide new light on a "tandem model" of driver behavior that includes both explicit and implicit processes involved in driving performance. The findings also suggest reasons drivers are most likely to crash at locations very near their homes. (C) 2013 Elsevier Ltd. All rights reserved.
Does driving experience in video games count? Hazard anticipation and visual exploration of male gamers as function of driving experience,
Risk perception and distribution of visual attention while driving are crucial elements for accident prevention and new-driver improvement. This study investigates how racing videogames could shape the visual exploration of virtual and real road in male pre-drivers. The visual performance of players of racing video games with and without driver’s license was tested in virtual vs. real scenarios. Attention to specific elements of different types of road interactions was monitored using an eye-tracking system. Results showed that habitual use of racing video games was not found to foster a positive effect on users’ distribution of visual attention, supporting visual patterns typical of novice drivers. Gamers without driving experience replicated the same patterns in a real road scenario, ignoring road signs and potential areas of interactions with other drivers, while experienced drivers gamers explored video games roads like real roads. The fact that the gamers’ driving performance was not comparable to drivers in the virtual scenario suggests that there are other variables in the gameplay that create a less complex traffic scene, still the visual complexity of different real road interactions is kept in video game interactions, opening new perspectives towards gamers’ visual exploration of the road.
Motorcyclists' speed and "looked-but-failed-to-see" accidents,
Previous research on motorcycle crashes has shown the frequency and severity of accidents in which a non-priority road user failed to give way to an approaching motorcyclist without seeing him/her, even though the road user had looked in the approaching motorcycle's direction and the motorcycle was visible. These accidents are usually called “looked-but-failed-to-see” (LBFS) accidents. This article deals with the effects that the motorcyclist's speed has in these accidents. It is based on the in-depth study and precise kinematic reconstruction of 44 accident cases involving a motorcyclist and another road user, all occurring in intersections. The results show that, in urban environments, the initial speeds of motorcyclists involved in “looked-but-failed-to-see” accidents are significantly higher than in other accidents at intersections. In rural environments, the difference in speed between LBFS accidents and other accidents is not significant, but further investigations would be necessary to draw any conclusions. These results suggest that speed management, through road design or by other means, could contribute to preventing “looked-but-failed-to-see” motorcycle accidents, at least in urban environments.
The role of motorcyclist and other driver behaviour in two types of serious accident in the UK,
Motorcycle accidents have somewhat different characteristics from accidents involving other classes of road user. They include in particular ‘right of way’ accidents, and accidents involving loss of control on curves or bends.A sample of 1790 accident cases was considered, including 1003 in detail, from UK midland police forces, involving motorcyclists of all ages, and covering the years 1997–2002 inclusive.Significant differences were discovered in the sample with respect to types of accidents involving motorcyclists (and their blameworthiness). There seems to be a particular problem surrounding other road users’ perception of motorcycles, particularly at junctions. Such accidents often seem to involve older drivers with relatively high levels of driving experience who nonetheless seem to have problems detecting approaching motorcycles. Motorcyclists themselves seem to have far more problems with other types of accident, such as those on bends or curves. The implications of these findings are discussed.
Looking behavior for vertical road signs,
Visual fixations at vertical road signs and their recall was tested in 22 participants who drove a route of 8.34km. Gaze was assessed by mobile eye tracking glasses. Recall was assessed at the end of the route by asking each participant to write in a route map all vertical sign that were remembered. The route was the same for all participants and included a total of 75 road signs. The results shown that only 25.06% of vertical signs were looked, and only 6.66% were recalled by the driver at the end of the route. The results are explained in terms of inattentional blindness, automaticity in driving behavior, and the angular offset of the vertical signs to the driver sight line.
Car drivers' skills and attitudes to motorcycle safety: A review
Car drivers' attitudes and visual skills in relation to motorcyclists.
Motorcyclists are grossly over-represented in the crash statistics. They represent 1 per cent of traffic in the United Kingdom but 21 per cent of all fatalities. The analysis of collision data suggests that some of the most common motorcyclist collisions involve errors on behalf of other road users, for example car drivers who fail to give way to an approaching motorcycle at a T-junction. Following such accidents, car drivers often claim that they looked, but did not see the approaching motorcycle. Research needs to assess whether such 'Look But Fail To See' accidents occur and what factors might contribute to their prevalence. This project involved three studies to explore these issues further. These were: 1. a study to increase car drivers' empathy for motorcyclists; 2. a study to investigate how drivers search for motorcycles at T-junctions and when changing lanes; and 3. a study to assess whether training interventions can address poor visual skills at T-junctions and when changing lanes.
Why do car drivers fail to give way to motorcycles at t-junctions?,
Studies of accident statistics suggest that motorcyclists are particularly vulnerable to collisions with other vehicles which pull out of side roads onto a main carriageway, failing to give way to the approaching motorcycle. Why might this happen? The typical response of the car driver is that they looked in the appropriate direction but simply failed to see the motorcycle. To assess the visual skills of drivers in such scenarios we compared the behaviour of novice and experienced drivers to a group of dual drivers (with both car and motorcycle experience). Participants watched a series of video clips, displayed across three screens, depicting the approach to various t-junctions. On reaching the junction, participants had to decide when it was safe to pull out. Responses and eye movements were measured. The results confirmed that dual drivers had the safest responses at junctions, especially in the presence of conflicting motorcycles. On a range of visual measures both novice and experienced drivers appeared inferior to dual drivers, though for potentially different reasons. There were however no differences in the time it took all drivers to first fixate approaching motorcycles. Instead the differences appeared to be due to the amount of time spent looking at the approaching motorcycle. The experienced drivers had shorter gazes on motorcycles than cars, suggesting that they either process less salient motorcycles faster than cars, or that they terminated the gaze prematurely perhaps because they did not realise they were fixating a motorcycle. We argue that this is potential evidence for an oculomotor basis for Look But Fail To See errors.
Perceptual training to increase drivers’ ability to spot motorcycles at T-junctions,
A different perspective on conspicuity related motorcycle crashes,
The most common type of conflict in which a motorcyclist is injured or killed is a collision between a motorcycle and a car, often in priority situations. Many studies on motorcycle safety focus on the question why car drivers fail to give priority and on the poor conspicuity of motorcycles. The concept of ‘looked-but-failed-to-see’ crashes is a recurring item. On the other hand, it is not entirely unexpected that motorcycles have many conflicts with cars; there simply are so many cars on the road. This paper tries to unravel whether – acknowledging the differences in exposure – car drivers indeed fail to yield for motorcycles more often than for other cars. For this purpose we compared the causes of crashes on intersections (e.g. failing to give priority, speeding, etc.) between different crash types (car–motorcycle or car–car). In addition, we compared the crash causes of dual drivers (i.e. car drivers who also have their motorcycle licence) with regular car drivers. Our crash analysis suggests that car drivers do not fail to give priority to motorcycles relatively more often than to another car when this car/motorcycle approaches from a perpendicular angle. There is only one priority situation where motorcycles seem to be at a disadvantage compared to cars. This is when a car makes a left turn, and fails to give priority to an oncoming motorcycle. This specific crash scenario occurs more often when the oncoming vehicle is a motorcycle than when it is a car. We did not find a significant difference between dual drivers and regular car drivers in how often they give priority to motorcycles compared to cars.
Reported road casualties Great Britain: main results: 2015 Retrieved fromon14/10/16.
Driver crash risk factors and prevalence evaluation using naturalistic driving data,
Background The purpose of this study was to examine the association between secondary task involvement and risk of crash and near-crash involvement among older drivers using naturalistic driving data. Methods Data from drivers aged ≥70 years in the Strategic Highway Research Program (SHRP2) Naturalistic Driving Study database was utilized. The personal vehicle of study participants was... [Show full abstract]
Effects of cognitive load on driving performance: The cognitive control hypothesis,
Objective: The main objective of this paper was to outline an explanatory framework for understanding effects of cognitive load on driving performance and to review the existing experimental literature in the light of this framework. Background: While there is general consensus that taking the eyes off the forward roadway significantly impairs most aspects of driving, the effects of primarily cognitively loading tasks on driving performance are not well understood. Method: Based on existing models of driver attention, an explanatory framework was outlined. This can be summarized in terms of the cognitive control hypothesis: Cognitive load selectively impairs driving sub-tasks that rely on cognitive control but leaves automatic performance unaffected. An extensive literature review was conducted where existing results were re-interpreted based on the proposed framework. Results: It was demonstrated that the general pattern of experimental results reported in the literature aligns well with the cognitive control hypothesis and that several apparent discrepancies between studies can be reconciled based on the proposed framework. More specifically, performance on non-practiced or inherently variable tasks, relying on cognitive control, is consistently impaired by cognitive load while the performance on automatized (well-practiced and consistently mapped) tasks is unaffected and sometimes even improved. Conclusion: Effects of cognitive load on driving are strongly selective and task-dependent. Application: The present results have important implications for the generalization of results obtained from experimental studies to real world driving. The proposed framework can also serve to guide future research on the potential causal role of cognitive load in real-world crashes.
Empirical evaluation of hazard anticipation behaviors in the field and on driving simulator using eye tracker
Modeling situation awareness and crash risk,
In this article we develop a model of the relationship between crash risk and a driver's situation awareness. We consider a driver's situation awareness to reflect the dynamic mental model of the driving environment and to be dependent upon several psychological processes including Scanning the driving environment, Predicting and anticipating hazards, Identifying potential hazards in the driving scene as they occur, Deciding on an action, and Executing an appropriate Response (SPIDER). Together, SPIDER is important for establishing and maintaining good situation awareness of the driving environment and good situation awareness is important for coordinating and scheduling the SPIDER-relevant processes necessary for safe driving. An Order-of-Processing (OP) model makes explicit the SPIDER-relevant processes and how they predict the likelihood of a crash when the driver is or is not distracted by a secondary task. For example, the OP model shows how a small decrease in the likelihood of any particular SPIDER activity being completed successfully (because of a concurrent secondary task performance) would lead to a large increase in the relative risk of a crash.
Attention and search conspicuity of motorcycles as a function of their visual context,
Over the years, PTWs number of accidents have increased dramatically and have accounted for a high percentage of the total traffic fatalities. The majority of those accidents occur in daylight, clear weather, and at light to moderate traffic conditions. The current study included two experiments. The first experiment evaluated the influence of PTW attention conspicuity on the ability of un-alerted viewers to detect it, whereas the second experiment evaluated the PTWs search conspicuity to alerted viewers. The independent variables in both experiments included driving scenarios (urban and inter-urban), PTW rider's outfit (black, white, and reflective) and PTW distance from the viewer. 66 students participated in experiment 1. Every participant was presented with a series of pictures and was asked to report all the vehicle types present in each picture. Experiment 2 included 64 participants and incorporated the same pictures as experiment 1. However, in this experiment the participants were instructed to search the pictures for a PTW and to report its presence or absence as soon as they reach a decision. In experiment 1 the detection of a PTW depended on the interaction between its distance from the viewer, the driving scenario and PTW rider's outfit. For an un-alerted viewer when the PTW was distant the different outfit conditions affected its attention conspicuity. In urban roads, where the background surrounding the PTW was more complex and multi-colored, the reflective and white outfits increased its attention conspicuity compared to the black outfit condition. In contrast, in inter-urban roads, where the background was solely a bright sky, the black outfit provided an advantage for the PTW detectability. In experiment 2, the average PTW detection rate of the alerted viewers was very high and the average reaction time to identify the presence of a PTW was the shortest in the inter-urban environment. Similar to the results of experiment 1, in urban environments the reflective and white clothing provided an advantage to the detection of the PTW, while in the inter-urban environment the black outfit presented an advantage. Comparing the results of the two experiments revealed that at the farthest distance, the increased awareness in the search conspicuity detection rates were three times higher than in the attention conspicuity. The conspicuity of a PTW can be increased by using an appropriate rider's outfit that distinguishes him/her from the background scenery. Thus, PTW riders can actively increase their conspicuity by taking into account the driving route (crowded urban/inter urban), eventually increasing the probability of being detected by the other road users. In addition, increasing the alertness and expectancy of drivers to the presence of PTWs can increase their search conspicuity.
A systematic review on factors affecting the likelihood of change blindness,
Background: The phenomenon of Change Blindness (CB) has been invoked in a number of fields of psychology, particularly eyewitness misidentification, but also hazard perception in driving behaviour. An extensive review of the existing literature suggested that there has been no systematic review to date that has investigated what factors affect CB in real-world contexts.Purpose: This article aims to systematically review factors affecting CB when measured using film or real-world paradigms.Method: Six electronic databases were searched for relevant references, alongside four E-theses. Seven experts were contacted for current and unpublished studies. Each study was compared against inclusion criteria, prior to selection and data synthesis.Results: The full search yielded 12,656 publications; 3,654 duplicates were removed and an additional 8,693 irrelevant publications were excluded. A further 295 publications were removed for not meeting the inclusion criteria. One conference abstract was excluded as contact with the authors produced no response. A total of 13 articles that met the criteria were reviewed.Conclusion: Increasing attention, the saliency of the changed object and spatial violations significantly reduce CB, specifically when measured using the real-world and film paradigms; these have implications for forensic psychology practice relevant to innocent bystanders and eyewitness misidentifications, and witnesses making positive identifications. However, a number of methodological limitations were identified which should be taken into account in designing future research.
Under high perceptual load, observers look but do not see. Applied Cognitive Psychology,(
react-text: 176 Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to... /react-text react-text: 177 /react-text [Show full abstract]
Do you see what eyes see? Implementing inattentional blindness,
This paper presents a computational model of visual attention incorporating a cognitive imperfection known as inattentional blindness. We begin by presenting four factors that determine successful attention allocation: conspicuity, mental workload, expectation and capacity. We then propose a framework to study the effects of those factors on an unexpected object and conduct an experiment to measure the corresponding subjective awareness level. Finally, we discuss the application of a visual attention model for conversational agents.
Driver workload during differing driving maneuvers,
Motorcycle-automobile accidents occur predominantly when the car driver turns left across the motorcyclist's right-of-way. Efforts to decrease this specific collision configuration, through an increase in motorcycle conspicuity, have concentrated on the physical characteristics of the motorcycle and its rider. The work reported here examines the behavior of car drivers during different driving sequences, in particular during left-turn maneuvers. An experiment is reported that used simultaneous video-taping of the driver and the forward-looking scene. Subjects followed a preset on-road course and were observed for head movements to determine the possibility of structural interference eye-blink frequency, probe-response time, and probe response error, as measures of cognitive or mental workload. In addition, the subjects completed two major subjective workload evaluations as reflections of effort directed to different components of the driving task. Results indicated that there were significant increases in head movements and mental workload during turn sequences compared to straight driving. This result of higher driver workload may be responsible for increasing the potential for detection failure. Such a propensity is also fostered by the higher structural interference that may be expected during turns. Failures to observe during turning sequences have differing outcomes depending on the presence of opposing traffic, as during the left turn, compared with the absence of such opposition, as occurs in the right turn. Also, the less conspicuous the oncoming vehicle in the left turn scenario, the higher the probability of detection failure. At the present time the least conspicuous powered vehicle is the motorcycle.
Alcohol increases inattentional blindness when cognitive resources are not consumed by ongoing task demands,
Inattentional blindness (IB) is the inability to detect a salient yet unexpected task irrelevant stimulus in one’s visual field when attention is engaged in an ongoing primary task. The present study is the first to examine the impact of both task difficulty and alcohol consumption on IB and primary task performance. On the basis of alcohol myopia theory, the combined effects of increased task difficulty and alcohol intoxication were predicted to impair task performance and restrict the focus of attention on to task-relevant stimuli. We therefore expected increases in breath alcohol concentration to be associated with poorer primary task performance and higher rates of IB, with these relationships being stronger under hard than easy task conditions. This hypothesis was tested in a field study where alcohol drinkers in a local bar were randomly assigned to perform a dynamic IB task with an easy or hard visual tracking and counting task at its core (Simons and Chabris in Perception 28:1059–1074,1999). Increasing the difficulty of the primary task reduced task accuracy but, surprisingly, had no impact on the rate of IB. Higher levels of alcohol intoxication were, however, associated with poorer task performance and an increased rate of IB, but only under easy primary task conditions. Results are consistent with alcohol myopia theory. Alcohol intoxication depletes attentional resources, thus reducing the drinker’s awareness of salient stimuli that are irrelevant to some ongoing primary task. We conclude that this effect was not observed for our hard task because it is more resource intensive, so leaves no spare attentional capacity for alcohol to deplete.
Effects of conversation on situation awareness and working memory in simulated driving,
In the present research, we investigated the hypothesis that working memory mediates conversation-induced impairment of situation awareness (SA) while driving. Although there is empirical evidence that conversation impairs driving performance, the cognitive mechanisms that mediate this relationship remain underspecified. Researchers have reported that a phonological working memory task decreased drivers' SA for vehicles located behind them whereas a visuospatial working memory task impaired SA for vehicles ahead. Conversation, therefore, might impair SA for vehicles behind the driver by preferentially taxing the phonological loop. A 20-questions task was used as a proxy for natural conversation. In Experiment I, driving performance was measured across three within-subjects conversation conditions (i.e., no conversation, driver asks questions, driver answers questions) with the use of a driving simulator. In Experiment 2, participants drove in the same simulator while either conversing (20-questions task) or not Participants estimated the positions of other vehicles after the screens were blanked at the end of each trial. Speed monitoring and responses to visual probes were impaired by the 20-questions conversation task (Experiment 1). As predicted, conversation impaired SA for the location of other vehicles more for vehicles located behind the driver than for those in front (Experiment 2). Conversation impairs drivers' SA of vehicles behind them by taxing working memory's phonological loop and impairs SA generally by taxing working memory's central executive. Provides a theoretical framework that links driver SA to working memory and a mechanism for understanding why conversation impairs driving performance.
Some factors affecting motorcyclists' conspicuity,
Three experiments examined some of the factors that might affect motorcyclists'' conspicuity to other road users. In each case, subjects saw a sequence of slides showing traffic, some of which contained a motorcyclist. A record was taken of their reaction times to decide whether or not a motorcyclist was present in each slide. Experiments 1 and 2 examined the effects on conspicuity of headlight use, type of clothing, distance of motorcyclist from viewer, and driving situation (urban or semi-rural). Experiment 3 looked more closely at environmental influences on motorcyclist conspicuity, systematically varying the level of background 090004clutter090005 behind the motorcyclist. All three experiments indicate that the effectiveness of the conspicuity aids used, especially clothing, may depend on the situation in which the motorcyclist was located: bright clothing and headlight use may not be infallible aids to conspicuity. Brightness contrast between the motorcyclist and the surroundings may be more important as a determinant of conspicuity than the motorcyclist''s brightness per se. Motorcyclists'' conspicuity is a more complex issue than has hitherto been acknowledged.
Safety in numbers for walkers and bicyclists: Exploring the mechanisms,
Industrial accident prevention: A scientific approach by H. W. Heinrich,
The effects of eye movements, spatial attention, and stimulus features on inattentional blindness,
Observers often fail to detect the appearance of an unexpected visual object (“inattentional blindness”). Experiment 1 studied the effects of fixation position and spatial attention on inattentional blindness. Eye movements were measured. We found strong inattentional blindness to the unexpected stimulus even when it was fixated and appeared in one of the expected positions. The results suggest that spatial attention is not sufficient for attentional capture and awareness. Experiment 2 showed that the stimulus was easier to consciously detect when it was colored but the relation of the color to the color of the attended objects had no effect on detection. The unexpected stimulus was easiest to detect, when it represented the same category as the attended objects.
The safety effects of daytime running lights: A perspective on daytime running lights (DRL) in the EU( Tech Rep. R-97-36).
What’s past is past: Neither perceptual preactivation nor prior motivational relevance decrease subsequent inattentional blindness,
Inattentional blindness—the phenomenon that clearly visible, yet currently unexpected objects go unnoticed when our attention is focused elsewhere—is an ecologically valid failure of awareness. It is currently subject to debate whether previous events and experiences determine whether or not inattentional blindness occurs. Using a simple two-phase paradigm in the present study, we found that the likelihood of missing an unexpected object due to inattention did not change when its defining characteristic (its color) was perceptually preactivated (Experiment 1; N 62=62188). Likewise, noticing rates were not significantly reduced if the object’s color was previously motivationally relevant during an unrelated detection task (Experiment 2; N 62=62184). These results corroborate and extend recent findings questioning the influence of previous experience on subsequent inattentional blindness. This has implications for possible countermeasures intended to thwart the potentially harmful effects of inattention.
The knowledge base of the oculomotor system,
In everyday life, eye movements enable the eyes to gather the information required for motor actions. They are thus proactive, anticipating actions rather than just responding to stimuli. This means that the oculomotor system needs to know where to look and what to look for. Using examples from table tennis, driving and music reading we show that the information the eye movement system requires is very varied in origin and highly task specific, and it is suggested that the control program or schema for a particular action must include directions for the oculomotor and visual processing systems. In many activities (reading text and music, typing, steering) processed information is held in a memory buffer for a period of about a second. This permits a match between the discontinuous input from the eyes and continuous motor output, and in particular allows the eyes to be involved in more than one task.
An investigation of the role of vehicle conspicuity in the 'looked but failed to see' error in driving
No abstract available
An analysis of 'looked but failed to see' accidents involving parked police vehicles,
Drivers who collide with a vehicle that is parked on the hard shoulder of a motorway or dual-carriageway sometimes claim not to have seen it before the collision. Previous research into vehicle conspicuity has taken such 090004looked but failed to see090005 claims at face value, and concentrated on attempting to remedy the problem by making vehicles more conspicuous in sensory terms. However, the present study describes investigations into accidents of this kind which have involved stationary police cars, vehicles which are objectively highly conspicuous. Two laboratory studies showed that experienced drivers viewing a film of dual-carriageway driving were slower to respond to a parked police car as a 090004hazard090005 if it was parked directly in the direction of travel than if it was parked at an angle; this effect was more pronounced when the driver''s attention was distracted with a secondary reasoning task. Taken together with the accident reports, these results suggest that 090004looked but failed to see090005 accidents may arise not because the parked vehicle is difficult to see, but for more cognitive reasons, such as vigilance failure, or possession by the driver of a 090004false hypothesis090005 about the road conditions ahead. An emergency vehicle parked in the direction of travel, with only its blue lights flashing, may encourage drivers to believe that the vehicle is moving rather than stationary. Parking at an angle in the road, and avoiding the use of blue lights alone while parked, are two steps that drivers of parked emergency vehicles should consider taking in order to alert approaching drivers to the fact that a stationary vehicle is ahead.
Distracted and confused?: Selective attention under load,
The ability to remain focused on goal-relevant stimuli in the presence of potentially interfering distractors is crucial for any coherent cognitive function. However, simply instructing people to ignore goal-irrelevant stimuli is not sufficient for preventing their processing. Recent research reveals that distractor processing depends critically on the level and type of load involved in the processing of goal-relevant information. Whereas high perceptual load can eliminate distractor processing, high load on ‘frontal’ cognitive control processes increases distractor processing. These findings provide a resolution to the long-standing early and late selection debate within a load theory of attention that accommodates behavioural and neuroimaging data within a framework that integrates attention research with executive function.
Role of sensory and cognitive conspicuity in the prevention of collisions between motorcycles and trucks at T-intersections,
Motorcyclists are particularly vulnerable to injury in crashes with heavy vehicles due to substantial differences in vehicle mass, the degree of protection and speed. There is a considerable difference in height between motorcycles and trucks; motorcycles are viewed by truck drivers from downward angles, and shorter distances between them mean steeper downward angles. Hence, we anticipated that the effects of motorcycle conspicuity treatments would be different for truck drivers. Therefore, this study aims to evaluate the effects of motorcycle conspicuity treatments on the identification and detection of motorcycles by truck drivers. Two complementary experiments were performed; the first experiment assessed the impact of motorcycle sensory conspicuity on the ability of un-alerted truck drivers to detect motorcycles, and the second experiment assessed the motorcycle cognitive conspicuity to alerted truck drivers. The sensory conspicuity was measured in terms of motorcycle detection rates by un-alerted truck drivers when they were not anticipating a motorcycle within a realistic driving scene, while the cognitive conspicuity was determined by the time taken by alerted truck drivers to actively search for a motorcycle. In the first experiment, the participants were presented with 10 pictures and were instructed to report the kinds of vehicles that were presented in the pictures. Each picture was shown to the participants for 600ms. In the second experiment, the participants were presented with the same set of pictures and were instructed to respond by clicking the right button on a mouse as soon as they detected a motorcycle in the picture. The results indicate that the motorcycle detection rate increases, and the response time to search for a motorcycle decreases, as the distance between the targeted motorcycle and the viewer decreases. This is true regardless of the type of conspicuity treatment used. The use of daytime running headlights (DRH) was found to increase the detection rate and the identification of a motorcycle by a truck driver at a farther distance, but effect deteriorates as the distance decreases. The results show that the detection rate and the identification of a motorcyclist wearing a black helmet with a reflective sticker increases as the distance between the motorcycle and the truck decreases. We also found that a motorcyclist wearing a white helmet and a white outfit is more identifiable and detectable at both shorter and longer distances. In conclusion, although this study provides evidence that the use of appropriate conspicuity treatments enhances motorcycle conspicuity to truck drivers, we suggest that more attention should be paid to the effect of background environment on motorcycle conspicuity.
Cross- cultural effects on the perception and appraisal of approaching motorcycles at junctions,
Both perceptual errors (failing to perceive) and appraisal errors (failing to make a correct judgment about safety) could explain the relatively high number of pulling out at the junctions involving approaching motorcycles in relation to cars. Two experiments were conducted to investigate the effect of exposure to motorcycles on these types of errors by comparing drivers from Malaysia where motorcycles are very common with drivers from the UK where motorcycles are rare. Experiment 1 investigated drivers ability to perceive approaching vehicles (car or motorcycle) located at different distances (near, intermediate and far) on UK and Malaysian roads. There was no difference between Malaysian and UK drivers in overall ability to perceive the approaching vehicles but Malaysian drivers were relatively good at perceiving motorcycles at further distances. Experiment 2 investigated drivers judgments about whether or not it was safe to pull out on the same roads and found that Malaysian drivers were more likely to judge it was safe to pull out as compared to UK drivers. Findings suggest that high exposure to motorcycles may reduce vehicle effects on perception for Malaysian drivers. However they may make more risky appraisals about safety of pulling out, which might contribute to the high accident and fatality rates in Malaysia.
Change detection in traffic: Where do we look and what do we perceive?,
The current study focuses on Change Blindness in a road environment. The purpose of the experiment is to study how the type of change induced affects the strength of Change Blindness and the role of glance duration and attention. Hundred-thirty-one participants watched video films showing six drives around a block filmed from the drivers viewpoint. They were instructed to look for a traffic related change from one drive to the next. Eye glance duration to traffic signs was measured, as well as Change Blindness. In drive 6, one of the traffic signs was changed into another traffic sign, with four different types of changes. The experiment showed that longer glances to the traffic signs in general predict Change Awareness in case of a change, whereas shorter glances predict Change Blindness. If the change is explicitly perceived, this resulted in even longer glances to the changed sign. Change detection improved with a larger difference between the original and the changed sign, with the traffic sign not fitting the scene and when attention was raised by means of an auditory message.Research highlights? Glance duration to stimuli in general predicts change detection. ? No indications of longer glances in condition that lead to better Change Detection. ? Large effect of type of change and fitting within the scene on change detection. ? No indications for implicit information processing for the Change Blind.
The view from the driver's seat: What good is salience?,
SummaryA set of experiments gauged the value of salient and non-salient visual information to drivers' decision making. Stimuli were images of traffic scenes viewed from a drivers' approximate perspective, and the subjects' task was to make stop-or-go driving judgments. Under some experimental conditions (Experiment 1), subjects viewed only the salient information from within each scene. Under other conditions (Experiments 2 3), they viewed only the non-salient information. A signal detection measure of sensitivity served as the primary dependent measure. Data indicated that an above-chance amount of the information needed for accurate judgments was contained within salient image regions and that some information was available only from the salient regions. Other critical information, however, was contained exclusively within non-salient regions. Results suggest that an attentional bias toward visual salience would serve as an economical information-seeking strategy for drivers but by itself would overlook many task-critical cues. Copyright 2013 John Wiley & Sons, Ltd.
Feature-based attentional set as a cause of traffic accidents,
Voluntary and relatively involuntary subsystems of attention often compete. On one hand, people can intentionally “tune” attention for features that then receive visual priority; on the other hand, more reflexive attentional shifts can “short-circuit” top-down control in the face of urgent, behaviourally relevant stimuli. Thus, it is questionable whether voluntary attentional tuning (i.e., attentional set) can affect one's ability to respond to unexpected, urgent information in the real world. We show that the consequences of such tuning extend to a realistic, safety-relevant scenario. Participants drove in a first-person driving simulation where they searched at every intersection for either a yellow or blue arrow indicating which way to turn. At a critical intersection, a yellow or blue motorcycle—either matching or not matching drivers’ attentional set—suddenly veered into drivers’ paths and stopped in their way. Collision rates with the motorcycle were substantially greater when the motorcycle did not match drivers’ attentional sets.
High perceptual load causes inattentional blindness and deafness in drivers,
Perceptual load theory of attention predicts that the level of perceptual load in a primary task affects the processing of additional stimuli. Given the lack of ecologically valid evidence for the model, the current study assessed the effect of perceptual load on driver awareness during simulated driving tasks. The results showed that perceptual load dramatically affected driver awareness for visual and auditory stimuli, even those that were driving relevant and safety critical (e.g. pedestrians or the sound of a car horn). The results support load theory and suggest that perceptual load may be an important factor in driver safety.
Public attitudes towards motorcyclists' safety: A qualitative study from the United Kingdom,
The aim of the reported research was to examine the perceptions of road user safety amongst different road users and examine the link between attitudes, empathy and skill in motorcycle safety behaviour. Motorcyclists were perceived by the study participants, members of the public at four different locations at the UK (including motorcyclists and non-motorcyclists), as a group be at a high risk of accidents on the road. This was due to perceived behavioural characteristics of motorcyclists – who were viewed as ‘thrill seekers’ – as well as observed behaviours on the road. This, coupled with the physical vulnerability and excessive speeds, meant that motorbike driving was considered by the study participants as the least safe form of road use. There was broad agreement that motorcycling was dangerous as a whole, but not all motorcyclists were necessarily risky riders. The issue of ‘competitive space’ emerged between car drivers and motorcyclists in particular and it was suggested that there was a lack of mutual awareness and considerations between the two groups. Generally, greatest empathy comes from drivers who are motorcyclists themselves. Engineering, education, enforcement interventions were investigated. These were aimed at two main areas: normalising safer driving behaviours for motorcyclists and increasing awareness of bikes for motorists—particularly in relation to reducing speed limits at urban junctions. Finally, the idea of risk mapping and reduced speed limits on rural roads was seen as potentially effective—particularly as certain motorcyclists highlighted that they changed their riding behaviours by increasing speed and taking greater risks on these roads.
Not all hazards are created equal: The significance of hazards in inattentional blindness for static driving scenes,
ABSTRACT Explaining how we attend to some objects and not others in real world environments remains a challenge for theories of attention. Driving is an ideal example of this, as it requires a complex synthesis of attentional processing, while still allowing attention to be captured by hazards. In the current study we employed a static inattentional blindness (IB) driving task in which participants were required to make decisions about the content of driving-related scenarios. In a critical trial, an additional stimulus was added to the driving scenario. All unexpected stimuli were thematically consistent with a normal driving environment but varied in their level of hazard threat. Rates of IB were consistent with the level of hazard threat of the stimuli. The results are discussed in terms of semantic-based attentional capture in driving, and models of IB.Copyright 2015 John Wiley & Sons, Ltd.
Attentional differences in driving judgments for country and city scenes: Semantic congruency in inattentional blindness,
ooked-but-failed-to-see vehicle collisions occur when a driver gives all indications of having responsibly evaluated the driving situation yet still fails to see a hazard that is clearly in view. The experience maps well onto the psychological phenomenon called inattentional blindness (IB). IB occurs when a viewer fails to see an unexpected object that is clearly visible, particularly if they are concentrating on an additional primary task. In this study, a driving-related IB task was used to explore whether an unexpected stimulus (US) such as a pedestrian or animal, is more likely to be seen in country or city-related driving scenarios if it is congruent or incongruent with the semantic context of the scenes, and thus congruent or incongruent with the attentional set of the viewer. Overall, participants were more likely to see the US in the City scenarios, which also demonstrated a borderline effect of congruency, with incongruent stimuli less likely to be seen than congruent stimuli. Analyses suggested that driver experience was related to detection of the US in City scenarios but not Country scenarios. However, analyses also revealed that participants generally tended to drive in city rather than country environments, thus prompting speculation that the results may reflect attentional requirements for familiar and unfamiliar driving scenarios. Thus we suggest that the analysis of the driving situation, and the attentional set that we develop to filter information, change when the driving situation is more familiar.
Representations reclaimed: Accounting for the co-emergence of concepts and experience,
The role of attentional breadth in perceptual change detection,
Previous research has shown that changes to scenes are often surprisingly hard to detect. The research reported here investigated the relationship between individual differences in attention and change detection. We did this by assessing participant breadth of attention in a functional field of view task (FFOV) and relating this measure to the speed with which individuals detected changes in scenes. We also examined how the salience, meaningfulness, and eccentricity of the scene changes affected perceptual change performance. In order to broaden the range of individual differences in attentional breadth, both young and old adults participated in the study. A strong negative relationship was obtained between attentional breadth and the latency with which perceptual changes were detected; observers with broader attentional windows detected changes faster. Salience and eccentricity had large effects on change detection, but meaning aided the performance of young adults only and only when changes also had low salience.
The influence of extrinsic motivation on competition-based selection,
The biased competition approach to visuo-spatial attention proposes that the selection of competing information is effected by the saliency of the stimulus as well as by an intention-based bias of attention towards behavioural goals. Wascher and Beste (2010)  showed that the detection of relevant information depends on its relative saliency compared to irrelevant conflicting stimuli. Furthermore the N1pc, N2pc and N2 of the EEG varied with the strength of the conflict. However, this system could also be modulated by rather global mechanisms like attentional effort. The present study investigates such modulations by testing the influence of extrinsic motivation on the selection of competing stimuli. Participants had to detect a luminance change in various conditions among others against an irrelevant orientation change. Half of the participants were motivated to maximize their performance by the announcement of a monetary reward for correct responses. Participants who were motivated had lower error rates than participants who were not motivated. The event-related lateralizations of the EEG showed no motivation-related effect on the N1pc, which reflects the initial saliency driven orientation of attention towards the more salient stimulus. The subsequent N2pc was enhanced in the motivation condition. Extrinsic motivation was also accompanied by enhanced fronto-central negativities. Thus, the data provide evidence that the improvement of selection performance when participants were extrinsically motivated by announcing a reward was not due to changes in the initial saliency based processing of information but was foremost mediated by improved higher-level mechanisms.
Attending overtaking cars and motorcycles through the mirrors before changing lanes,
Right of way violation crashes are the most common type of accidents that motorcyclists face. This study assessed right of way decisions in scenarios which require noticing whether there is traffic from behind that is about to overtake. A test was created which presents participants clips with a wide field of vision (from a driver's perspective in a moving vehicle), with mirror information inset that allows either cars or motorcycles that are about to overtake, to be attended. Novice and experienced car drivers, and dual drivers (with both car and motorcycle experience), watched these clips while their eye movements were monitored. The results indicated that in the rear-view and the right-side mirrors, and in the right hand lane, conflicting motorcycles garnered more attention than conflicting cars. This pattern however was particularly driven by the dual drivers group. Additionally, novice drivers and dual drivers made more use of the right side mirror than the experienced drivers. Dual drivers also made more use of the rear view mirror than experienced drivers. Finally, significant positive correlations that were found between percentages of safe manoeuvres and measures of visual search provide direct evidence demonstrating that the frequency of risky manoeuvres was indeed larger in those cases where less time was spent gazing at the mirrors, indicating that the additional attention devoted to process conflicting vehicles contributes to reduce risky manoeuvres. The general pattern of results also provides some indirect support that non-motorcyclists drivers are more likely to have Look But Fail To See errors with conflicting motorcycles than motorcyclist drivers.
Drivers' visual scanning impairment under the influences of alcohol and distraction: A literature review,
What controls attention in natural environments?,
The highly task-specific fixation patterns revealed in performance of natural tasks demonstrate the fundamentally active nature of vision, and suggest that in many situations, top-down processes may be a major factor in the acquisition of visual information. Understanding how a top-down visual system could function requires understanding the mechanisms that control the initiation of the different task-specific computations at the appropriate time. This is particularly difficult in dynamic environments, like driving, where many aspects of the visual input may be unpredictable. We therefore examined drivers' abilities to detect Stop signs in a virtual environment when the signs were visible for restricted periods of time. Detection performance is heavily modulated both by the instructions and the local visual context. This suggests that visibility of the signs requires active search, and that the frequency of this search is influenced by learnt knowledge of the probabilistic structure of the environment.
Gorillas in our midst: Sustained inattentional blindness for dynamic events,
With each eye fixation, we experience a richly detailed visual world. Yet recent work on visual integration and change direction reveals that we are surprisingly unaware of the details of our environment from one view to the next: we often do not detect large changes to objects and scenes ('change blindness'). Furthermore, without attention, we may not even perceive objects ('inattentional blindness'). Taken together, these findings suggest that we perceive and remember only those objects and details that receive focused attention. In this paper, we briefly review and discuss evidence for these cognitive forms of 'blindness'. We then present a new study that builds on classic studies of divided visual attention to examine inattentional blindness for complex objects and events in dynamic scenes. Our results suggest that the likelihood of noticing an unexpected object depends on the similarity of that object to other objects in the display and on how difficult the priming monitoring task is. Interestingly, spatial proximity of the critical unattended object to attended locations does not appear to affect detection, suggesting that observers attend to objects and events, not spatial positions. We discuss the implications of these results for visual representations and awareness of our visual environment.
Situation awareness and transitions in highly automated driving: A framework and mini review,
SPIDER: A framework for understanding driver distraction,
OBJECTIVE: The objective was to identify key cognitive processes that are impaired when drivers divert attention from driving. BACKGROUND: Driver distraction is increasingly recognized as a significant source of injuries and fatalities on the roadway. METHOD/RESULTS: A "SPIDER" model is developed that identifies key cognitive processes that are impaired when drivers divert attention from driving. SPIDER is an acronym standing for scanning, predicting, identifying, decision making, and executing a response. CONCLUSION: When drivers engage in secondary activities unrelated to the task of driving, SPIDER-related processes are impaired, situation awareness is degraded, and the ability to safely operate a motor vehicle may be compromised. APPLICATION: The pattern of interference helps to illuminate the sources of driver distraction and may help guide the integration of new technology into the automobile.Keywords: Driver distraction;
The role frontal motorcycle conspicuity has in road accidents,
Since motorcyclists are over-involved in accidents, it is of some importance to determine whether or not the use of headlights during daylight might lead to a reduction in such accidents. While some U.S. states have laws in this regard, and other places including Australia have recommendations that such a policy become law, a study was made to help a decision as to whether or not the policy should be introduced into New Zealand. Studies reviewed included those of accident characteristics, those concerning daylight running-light use on automobiles, and those involving day time light use on motorcycles. Physiological and psychological reasons for conspieuity (or lack thereof) of an object are also reviewed, as are factors affecting perceptual processes. It is concluded that compulsory usage of motorcycle headlights should be favored and that New Zealand is very likely to have a benefit-cost ratio exceeding l if such a policy is adopted.
Motorcycle conspicuity: Effects of age and daytime running lights,,
Objective:This study investigated variables that may contribute to motorcycle conspicuity within a high-fidelity simulated environment. The variables included motorcycle lighting, vehicular daytime running lights (DRLs), and age of the driver of the other vehicle.Background: Research suggests that decreased levels of conspicuity associated with riding a small two-wheeled vehicle reduce the ability of other drivers to detect and respond to that vehicle effectively. This lack of conspicuity is often responsible for the frequent injuries and fatalities incurred by motorcycle riders.Method: The 75 participants who took part in this study watched a series of video clips of roadway traffic and were asked to indicate when they saw a hazardous situation, such as the presence of pedestrians, motorcycles, or traffic cones. Both motorcycle and following-vehicle lights were manipulated, and participant reaction times were collected and analyzed.Results: Analyses indicated main effects for all three variables as well as interaction effects between motorcycle lighting and vehicle-following conditions. Overall, findings showed a link between DRLs and the effective detection of motorcycles and suggested that age-related changes affect the ability to detect and respond to a motorcycle effectively.Conclusion: Although our laboratory findings corroborated previous correlational studies, further research in real-world settings, such as those with high-density traffic or under adverse environmental conditions, needs to be conducted.Application: Potential applications of this research include the assessment of appropriate lighting technology to enhance conspicuity of motorcycles and reduce the high rate of fatalities and injuries related to motorcycle crashes.
Inattentional blindness reflects limitations on perception, not memory: Evidence from repeated failures of awareness,
Abstract Perhaps the most striking phenomenon of visual awareness is inattentional blindness (IB), in which a surprisingly salient event right in front of you may go completely unseen when unattended. Does IB reflect a failure of perception, or only of subsequent memory? Previous work has been unable to answer this question, due to a seemingly intractable dilemma: ruling out memory requires immediate perceptual reports, but soliciting such reports fuels an expectation that eliminates IB. Here we introduce a way of evoking repeated IB in the same subjects and the same session: we show that observers fail to report seeing salient events' not only when they have no expectation, but also when they have the wrong expectations about the events nature. This occurs when observers must immediately report seeing anything unexpected, even mid-event. Repeated IB thus demonstrates that IB is aptly named: it reflects a genuine deficit in moment-by-moment conscious perception, rather than a form of inattentional amnesia.
Motorcycle rider conspicuity and crash related injury: Case-control study,
Objective To investigate whether the risk of motorcycle crash related injuries is associated with the conspicuity of the driver or vehicle. Design Population based case-control study. Setting Auckland region of New Zealand from February 1993 to February 1996. Participants 463 motorcycle drivers (cases) involved in crashes leading to hospital treatment or death; 1233 motorcycle drivers (controls) recruited from randomly selected roadside survey sites. Main outcome measures Estimates of relative risk of motorcycle crash related injury and population attributable risk associated with conspicuity measures, including the use of reflective or fluorescent clothing, headlight operation, and colour of helmet, clothing, and motorcycle. Results Crash related injuries occurred mainly in urban zones with 50 km/h speed limit (66%), during the day (63%), and in fine weather (72%). After adjustment for potential confounders, drivers wearing any reflective or fluorescent clothing had a 37% lower risk (multivariate odds ratio 0.63,95% confidence interval 0.42 to 0.94) than other drivers. Compared with wearing a black helmet, use of a white helmet was associated with a 24% lower risk (multivariate odds ratio 0.76,0.57 to 0.99). Self reported light coloured helmet versus dark coloured helmet was associated with a 19% lower risk. Three quarters of motorcycle riders had their headlight turned on during the day, and this was associated with a 27% lower risk (multivariate odds ratio 0.73,0.53 to 1.00). No association occurred between risk and the frontal colour of drivers' clothing or motorcycle. If these odds ratios are unconfounded, the population attributable risks are 33% for wearing no reflective or fluorescent clothing, 18% for a non-white helmet, 11% for a dark coloured helmet, and 7% for no daytime headlight operation. Conclusions Low conspicuity may increase the risk of motorcycle crash related injury. Increasing the use of reflective or fluorescent clothing, white or light coloured helmets, and daytime headlights are simple, cheap interventions that could considerably reduce motorcycle crash related injury and death.
Motorcycle conspicuity: An evaluation and synthesis of influential factors,
vere injuries, as opposed to 14.1% of the automobile accidents (Appel, Otte, & Wiis- temann, 1986, p. 97). Taking into account miles of travel, the death rate in the U.S. for motorcycle riders of about 35 per 100,000,000 miles of travel contrasts with an overall motor vehicle death rate of 2.57 per 100,000,000 miles (National Safety Council, 1987). In West Germany, the death rate by kilometers traveled is 44 times higher for motorcyclists than for automobile driv- ers (Appel et al., 1986). Another illustration of the differing risks involved in riding a motorcycle or driving a car is presented in Table 1, which contains the average times and distances of travel until the occurrence of an accident resulting in an injury or a fatality.
4.2.1 驾驶图式对预期的积极影响 ...
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