Driving without awareness: The effects of practice and automaticity on attention and driving

This research examined the development of proceduralised “driving without awareness” in a driving simulator by paying participants to drive a simulated road regularly over 12 weeks of testing. This longitudinal research paradigm is a significant departure from previous studies which have examined drivers in a conscious attentional mode using short experimental sessions or cross-sectional designs comparing expert and novice performance. During each session, participants took two “trips” on the simulated road; sometimes travelling on a “to and from” journey on one half of the road, sometimes traversing the entire road in one direction. A range of measures, including driving performance, vehicle detection, perceptual speed regulation, and hazard reactions were collected. The results showed the development of driving patterns and changes in object detection performance indicative of proceduralised driving. Speed and lane position variability quickly decreased with practice, as did participants’ subjective experiences of driving difficulty. Performance on an embedded detection task appeared to become a proceduralised part of the driving task, becoming highly efficient in later stages of the experiment. The changes in attentional focus and driving performance over time provide new light on previous research findings and allow us to critically re-examine several established models of driver behaviour.     

Mapping visual attention with change blindness: new directions for a new method

Change blindness provides a new technique for mapping visual attention with unprecedented spatial and temporal resolution. Change blindness can occur when a brief full-field blank interferes with the detection of changes in a scene that occur during the blank. This interference can be overcome by attending to the location of a change. Because changes are detected at attended locations, but not at unattended locations, detection accuracy provides an indirect measure of the distribution of visual attention. The likelihood of detecting a new element in a scene provides a measure of the occurrence of attention at that element’s location. Potential new directions, advantages, and problems with this method are considered.     

Hide-and-seek around the centre of interest: The dead zone of attention revealed by change blindness

Three experiments examined spatial allocation of attention during active search for visual changes. In all experiments, there were three conditions of change location related to a centre of interest: (1) Central (most attended location itself), (2) near, and (3) far marginal change. In Experiment 1, participants showed the slowest search and the largest number of undetected changes in near condition. Moreover, they misidentified near changes more frequently than central and far ones. In Experiment 2, participants had to search for marginal changes in the presence of a once noticed central change that summoned additional attention to a central location. It resulted in further search slowing for near changes. In Experiment 3, participants searched for one of two concurrent marginal changes in the presence of a central one. They detected far changes about 2.3 times more frequently than near ones. Taken together, these results support the notion of “dead zone of attention” surrounding attentional focus. Several speculations about the nature of dead zone are discussed.     

Driver perception hypothesis: Driving simulator study

According the driver perception hypothesis, horizontal curves appear sharper or flatter when overlapping with crest or sag vertical curves, respectively. Confirmations of this hypothesis are provided by studies carried out using non-interactive techniques that do not allow the analysis of the driver’s reactions to the visual perception of the road.This study was aimed to add to the body of knowledge concerning driver’s speed behavior on combined curves, as well as to test the perception hypothesis based on the speed data collected during tests in the interactive CRISS driving simulator.Speeds on the tangent-curve transition of crest and sag combinations were compared to those on the tangent-curve transition of horizontal curves with the same radii but on a flat grade (reference curves).For the crest combinations the results of the statistical analyses were fully consistent with the perception hypothesis. On the sag combinations, on the contrary, the driver’s speed behavior did not differ in any statistically significant way from that on the reference curves. Therefore this finding did not support the perception hypothesis on the sag combinations. The effects of the combined curves on the driver’s speed behavior did not change in function of the level of the radius. Some implications of these findings have been highlighted.     

Driver's avoidance characteristics to hazardous situations: A driving simulator study

When analyzing the causes of an accident, it is critical to determine whether the driver could have prevented the accident. In previous studies on the reaction times of drivers, the definition and values of reaction times vary, so applying reaction time is difficult. In such analysis, the driver’s reaction time from perception is required to determine whether the driver could have prevented the accident, but past studies are difficult to utilize in accident analysis as reaction time measurements were taken after the occurrence of hazardous situations. In this study, 93 subjects from age groups ranging from 20 s to 40 s participated in an experiment inside a full-scale driving simulator, to determine reaction time values that can be practically applied to accident analysis. A total of 4 hazardous accident situations were reproduced, including driving over the centerline, pedestrian jaywalking, a vehicle cutting in, and intersection traffic signal violation. The Time-To-Collision (TTC) was 2.5 s and the driving speed was set to the common city road speed limits of 60 and 80 km/h. An eye tracker was used to determine the driver’s Saccade Latency (SL) during hazardous situations. Brake Reaction Time from Perception (BRT_P), Steer Reaction Time from Perception (SRT_P), and Driver Reaction Time from Perception (DRT_P) were derived, and the measurements were statistically analyzed to investigate differences by age group, gender, speed, and type of hazardous situation. Most participants were found to avoid collisions by braking first rather than steering for the presented hazardous situations, except for the cutting in situation. Also, to determine a reaction time that would cover most drivers, the 85th percentile of DRT_P was calculated. The 85th percentile of DRT_P was in the range of 0.550 – 0.800 s. Specifically for each hazardous situation, it was 0.650 s for driving over the centerline, 0.800 s for the pedestrian jaywalking, 0.660 s for cutting in, and 0.550 s for the intersection traffic signal violation. For all 4 hazardous situations combined, the 85th percentile of DRT_P was 0.646 s. The findings can be utilized to determine the driver’s likelihood of avoiding accidents when faced with similar hazardous situations.     

The effect of cueing on change blindness and same blindness

We used the change blindness paradigm of Landman, Spekreijse, and Lamme (2003) to measure the effect of cues on the ability to detect changes between two presentations of an array of eight rectangles separated by an interstimulus interval (ISI). Next, we measured the ability to detect sameness as the target rectangle remained the same when all of the others changed orientation. We were surprised to find no difference between change-detection and same-detection performance. These results (1) are consistent with the notion that some kind of internal representation was cued during the ISI, (2) mitigate against the recruitment of grouping strategies and/or forming a Gestalt, and (3) imply that under conditions facilitated by cues same-detection performance can be as good as change-detection performance.     

Sleep loss and change detection in driving scenes

Driver sleepiness is a significant road safety problem. Sleep-related crashes occur on both urban and rural roads, yet to date driver-sleepiness research has focused on understanding impairment in rural and motorway driving. The ability to detect changes is an attention and awareness skill vital for everyday safe driving. Previous research has demonstrated that person states, such as age or motivation, influence susceptibility to change blindness (i.e., failure or delay in detecting changes). The current work considers whether sleepiness increases the likelihood of change blindness within urban and rural driving contexts. Twenty fully-licenced drivers completed a change detection ‘flicker’ task twice in a counterbalanced design: once following a normal night of sleep (7–8 h) and once following sleep restriction (5 h). Change detection accuracy and response time were recorded while eye movements were continuously tracked. Accuracy was not significantly affected by sleep loss; however, following sleep loss there was some evidence of slowed change detection responses to urban images, but faster responses for rural images. Visual scanning across the images remained consistent between sleep conditions, resulting in no difference in the probability of fixating on the change target. Overall, the results suggest that sleep loss has minimal impact on change detection accuracy and visual scanning for changes in driving scenes. However, a subtle difference in response time to change detection between urban and rural images indicates that change blindness may have implications for sleep-related crashes in more visually complex urban environments. Further research is needed to confirm this finding.     

Driving around bends with or without shoulders: The influence of bend direction

Paved shoulders have long been used to create “forgiving” roads where drivers can maintain control of their vehicles even when as they drift out of the lane. While the safety benefits of shoulders have been well documented, their effects on driver behavior around curves have scarcely been examined. The purpose of this paper is to fill this gap by assessing whether the addition of shoulders affects driver behavior differently as a function of bend direction. Driver behavior in a driving simulator was analyzed on left and right curves of two-lane rural roads in the presence and absence of 0.75-m and 1.25-m shoulders. The results demonstrated significant changes in drivers’ lateral control when shoulders were provided. In the absence of oncoming traffic, the shoulders caused participants to deviate more toward the inner lane edge at curve entry, at the apex and at the innermost position on right bends but not left ones. In the presence of oncoming traffic, this also occurred at the apex and the innermost position, leading participants to spend more time off the lane on right curves. Participants did not slow down in either traffic condition to compensate for steering farther inside, thereby increasing the risk of lane departure on right curves equipped with shoulders. These findings highlight the direction-specific influence of shoulders on a driver’s steering control when driving around bends. They provide arguments supporting the idea that drivers view paved shoulders as a new field of safe travel on right curves. Recommendations are made to encourage drivers to keep their vehicle within the lane on right bends and to prevent potential interference with cyclists when a shoulder is present.     

Driving demands,stress reactivity and driving behavior: An interactional approach

The aim of the present study was to investigate the role of driving demands, neuroticism, and their interaction when predicting driving behavior. More precisely, we strived to examine how driving behaviors (i.e., speeding, winding, tailgating and jerky driving) unfold across low and high driving demands and whether they are contingent on a personality factor that has previously been linked to stress reactivity. In a driving simulator, 50 participants with a valid driver’s license (56.6% female, age: M = 30.13, SD = 10.16) were exposed to driving scenarios of different levels of information processing and vehicle handling demands. Additionally, they filled-out a self-report questionnaire that measured their neuroticism. We found that driving behavior became safer in scenarios that were highly demanding in terms of information processing, while this pattern did not emerge with vehicle handling demands. Moreover, tentative support was found for the notion that individuals high in neuroticism are less able to adapt their behavior to higher information processing demands. The present study offers new insights on driving demands in a simulated driving context and points to the potential importance of exploring interactions between personality and situational factors when understanding driving behavior. Additionally, the results of the present study may be used to adapt driver’s education programs.     

Mind the gap: Misdirection, inattentional blindness and the relationship between overt and covert attention

The present commentary addresses two issues arising from Memmert’s (2010) paper. First, can the ‘misdirection’ and ‘inattentional blindness’ paradigms provide important insights into the relationship between ‘overt’ and ‘covert’ attentional processes? Second, what are the most fruitful directions for research that seeks to combine these attentional paradigms in ecologically valid settings? We argue that although Memmert’s (2010) paper postulates several important differences between the misdirection and inattentional blindness paradigms, it may not emphasise sufficiently strongly the significant insights into attention that have been yielded by the former approach. To illustrate, we discuss the utility of the misdirection paradigm in providing an ecologically valid method to investigate the relationship between overt and covert attentional processes. Such naturalistic methods are required to ensure optimal integration of the misdirection and inattentional blindness paradigms within a general theory of attention.     

Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects

To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance.     

The influence of distracter and target features on distracter induced blindness

The inhibitory effect of the processing of target-like distracters has already been shown to affect the conscious detection of simple motion and simple orientation stimuli in a random dot kinematogram. In two experiments we examined the effects of single-feature motion distracters, single-feature orientation distracters, and combined-feature distracters containing both motion and orientation information. The target was specified as a coherent motion episode (Experiment 1) or as a combined-feature episode where the coherent motion was accompanied by an abrupt change in line orientation (Experiment 2). Results showed that (a) the respective feature-specific inhibitory processes operate separately even when the distracter features are presented simultaneously and (b) both inhibitory processes contribute to the blindness effect when the conjunction of two features is defined as the target. Again, this inhibitory-process is feature-specific: Only features that are defined in the task are represented in the inhibitory task set. In case of combined- feature task-sets, these representations remain separate, so that combined-feature distracters as well as single-feature distracters are able to induce blindness effects.     

How something can be said about telling more than we can know: on choice blindness and introspection

The legacy of Nisbett and Wilson’s classic article, Telling More Than We Can Know: Verbal Reports on Mental Processes (1977), is mixed. It is perhaps the most cited article in the recent history of consciousness studies, yet no empirical research program currently exists that continues the work presented in the article. To remedy this, we have introduced an experimental paradigm we call choice blindness [Johansson, P., Hall, L., Sikström, S., &; Olsson, A. (2005). Failure to detect mismatches between intention and outcome in a simple decision task. Science, 310(5745), 116–119.]. In the choice blindness paradigm participants fail to notice mismatches between their intended choice and the outcome they are presented with, while nevertheless offering introspectively derived reasons for why they chose the way they did. In this article, we use word-frequency and latent semantic analysis (LSA) to investigate a corpus of introspective reports collected within the choice blindness paradigm. We contrast the introspective reasons given in non-manipulated vs. manipulated trials, but find very few differences between these two groups of reports.     

Release of inattentional blindness by high working memory load: elucidating the relationship between working memory and selective attention

An unexpected stimulus often remains unnoticed if attention is focused elsewhere. This inattentional blindness has been shown to be increased under conditions of high memory load. Here we show that increasing working memory load can also have the opposite effect of reducing inattentional blindness (i.e., improving stimulus detection) if stimulus detection is competing for attention with a concurrent visual task. Participants were required to judge which of two lines was the longer while holding in working memory either one digit (low load) or six digits (high load). An unexpected visual stimulus was presented once alongside the line judgment task. Detection of the unexpected stimulus was significantly improved under conditions of higher working memory load. This improvement in performance prompts the striking conclusion that an effect of cognitive load is to increase attentional spread, thereby enhancing our ability to detect perceptual stimuli to which we would normally be inattentionally blind under less taxing cognitive conditions. We discuss the implications of these findings for our understanding of the relationship between working memory and selective attention.     

The relationship between fluid intelligence and sustained inattentional blindness in 7-to-14-year-old children

Previous researches have shown that people with higher fluid intelligence are more likely to detect the unexpected stimuli. The current study systematically explored the relationship between fluid intelligence and sustained inattentional blindness in children. In Experiment 1, we measured one hundred and seventy-nine 7-to-14-year-old children’s fluid intelligence and sustained inattentional blindness. The results showed that fluid intelligence was negatively related to sustained inattentional blindness only in 7-to-8-year-old children. In Experiment 2, we explored sustained inattentional blindness in sixty children with high Raven’s scores. We found that compared with children who have average Raven’s scores aged 11-to-12 years old, children with high Raven’s scores were unable to better avoid sustained inattentional blindness. In general, this research implies that the relation between fluid intelligence and sustained inattentional blindness is weak. Fluid intelligence could predict sustained inattentional blindness only when children do not have enough perceptual capacities to complete the primary task.     

Effects of directional auditory and visual warnings at intersections on reaction times and speed reduction times

Intersection collision warning systems (ICWSs) have an important impact on driving safety because making the potential collision at intersection predictable, allow reducing the probability and severity of accidents. Among the several types of alarms to alert the driver of an imminent collision, those most used concerning the auditory and the visual stimulus. However, it is unclear whether is more effective an audio or a visual warning. In addition, no study compared the effects on drivers’ behavior induced by an acoustic and a visual directional warning. The main objective of the present study was to assess, in response to a potential conflict event at the intersections, the effects of directional auditory and visual warnings on driving performance.A driving simulator experiment was carried out to collect drivers’ behavior in response to a vehicle that failed to stop at the intersection. The parameters reaction time and speed reduction time were used for the evaluation of the effects on driving performance. These duration variables were modeled following the survival analysis, by the use of the accelerated failure time duration model with a Weibull distribution.Results showed that when the directional warning system (auditory or visual) was present, the drivers were able to detect earlier the violator vehicle. This effect led to a more comfortable braking maneuver and, thus, less possibilities of an unexpected maneuver for the following vehicle, avoiding the car – following collisions. The effectiveness of ICWSs was more evident for the directional auditory speech message; for this condition, in fact, the lower reaction time and the longer speed reduction time were obtained.The outcomes of the present study provide useful suggestions about the most effective collision warning systems that the automotive industry should develop and equip on vehicles.     

Driving distraction at night: The impact of cell phone use on driving behaviors among young drivers

Currently, young drivers are more likely than other drivers to use cell phones while driving at night, which has become a major cause of road crashes. However, limited attention has been given to distracted nighttime driving. Therefore, the aim of this study was to explore the interaction effect of cell phone use and time of day (daytime and nighttime) on young drivers’ car-following performance. Forty-three young drivers engaged in a driving simulator experiment with a within-subject design that included three distractions (no distraction, talking and texting on a cell phone) and two times of day. This paper applied non-parametric tests to analyze the data and obtained the following results: (1) the standard deviation of lane position (SDLP) did not significantly differ at either time of day under no distraction, but it was significantly higher at night on straight roads and large-radius curves after introducing distractions. In addition, participants drove faster and gave less headway on small-radius curves under both distractions at night; (2) texting significantly increased the SDLP, while there was less lateral variation during the talking tasks than under no distraction on simple road sections; and (3) compared with the experienced drivers, the novice drivers drove faster during the talking tasks on small-radius curves, but there was no significant difference between groups during the texting tasks. These findings provide both theoretical and practical implications for related policy makers to enhance traffic safety.     

Effect of chevron design on driver behaviour when encountering and passing through a dangerous curve

Horizontal curves are locations on the road network with a high road accident risk. In order to provide drivers with timely and proper information about the upcoming curve, road authorities often use chevron signs. Although the main design of chevrons is similar in most countries (one colour for the background and another for the arrow), the combination of colours differs. The aim of this simulator study is to investigate how different colour combinations affect drivers when they encounter and drive through horizontal curves on rural roads at daytime. Overall, each of the tested chevrons reduced the driving speed (between 25 and 29 km/h), although not to the speed limit level (60 km/h). However, for curves marked with chevrons with fluorescent or white background the driving speed was the lowest at all measuring points, regardless of the curve direction. The observation of lateral movement shows that there are no significant differences in the way the vehicle is positioned when approaching and driving through curves marked with different chevrons. Based on the obtained results, practical recommendations and potential future research activities are presented.     

Improved driver behaviour at bus stops on local roads: Comparison of different treatments

Every day, millions of students use school bus as a mean of transportation to and from schools. Nevertheless, most of the school bus related crashes occur at or near bus stops. The overtaking of stopped school buses during boarding and alighting of students imposes safety risks on students and drivers. This study aims to investigate the impact of three different treatments on driving behavior at bus stops. In total, this study compared four different conditions. Three of them were treatment conditions namely (Red Pavement, Road Narrowing, and smart LED), which were compared with a control condition (i.e., the default bus stop layout without any additional treatments as implemented in the State of Qatar). Each condition was tested for three situations. Situation 1 and Situation 2 were designed with the presence of a stopped school bus on the same and on the opposite travel directions, respectively, while, Situation 3 was designed without any school bus at the bus stop location. A total of 72 subjects participated in the experiment. Generalized Linear Mixed Model (GLMM) was employed to study the impact of several factors on the overtaking/crossing probability of the stopped school bus. In Situation 1, Road_narrowing condition outperformed the other conditions by making 94.3 % of drivers to stop for the bus, while in Situation 2, LED condition performed best by making 48.6 % of drivers stop for the bus that is stopped at the opposite travel direction. Moreover, the LED and Road_narrowing treatments were effective in moderating drivers’ speed behavior, lowering their traveling speed by 5.16 km/h and 5.11 km/h, respectively even in the absence of any bus at the bus stop. Physical road narrowing condition outperformed the other tested conditions, and therefore, can be recommended as a low-cost treatment to improve safety at bus stops. In locations where the implementation of physical road narrowing is not feasible, LED treatment can be used to moderate driver traveling speed and stopping behavior.     

Dynamic traffic management on a familiar road: Failing to detect changes in variable speed limits

Variable speed limits (VSL) are used more commonly around the globe lately. Although on a macroscopic level positive effects of VSLs have been reported, the caveat is that the impact of VSLs is very sensitive to the level of driver compliance. Thus far it is unknown whether all individual drivers are actually able to notice when a speed limit changes into another speed limit; a prerequisite for purposeful speed limit compliance in the first place. To simulate regular driving conditions, twenty-four participants were familiarised with a particular route by driving the same route in a driving simulator nineteen times on five separate days. Part of the route consisted of a motorway where VSL signs were regularly displayed above every driving lane. At drive nineteen, speed limits changed from 80 km/h to 100 km/h on four out of eight consecutive signs. After passing all signs, one expects 6.25% of the participants still to be unaware that the speed limit had increased (based on chance), while the results showed most participants had failed to notice the speed limit change (58.3%). Instead, they saw what they expected to see: a speed limit of 80 km/h. If the speed change had been vice versa, in other words from 100 km/h to 80 km/h, this would immediately result in speed offences, though not deliberately at all.