Looming Auditory and Vibrotactile Collision Warning for Safe Driving

Looming auditory warning signals (that is, signals whose intensity increases over time) have proven to be particularly effective in terms of reducing a driver’s brake reaction times (BRTs) to impending collisions, and are also associated with very low false alarm rates. We report two experiments designed to further investigate how the presentation of looming auditory warnings with increasing frequency or increasing spatial extent would compare to those with increasing intensity. A third experiment was conducted in order to evaluate the potential efficacy of presenting looming warnings to drivers in another modality, namely via vibrotactile signals. Participants’ speeded BRTs to potential collision events following the presentation of various warning signals in a simulated car following scenario were measured. While both looming frequency and spatial warnings were effective in terms of speeding the driver’s responses to critical driving events, the magnitude of the benefit resembled that of a typical nonlooming constant intensity warning. Looming intensity warnings outperformed their looming frequency counterparts in terms of facilitating drivers’ collision avoidance responses. As for vibrotactile warnings, the results revealed that looming vibrotactile stimuli did not offer any additional benefits over and above the other non-looming vibrations tested in the study. The implications of these findings for collision warning systems design are discussed

Informative Collision Warnings: Effect of Modality and Driver Age

Research has revealed that when drivers are presented with an informative tactile collision warning, they are able to produce faster braking reaction times (BRTs) which may potentially reduce the likelihood and severity of rear-end collisions. To expand on this research, we investigated the effectiveness of unimodal (tactile) and multisensory (audiotactile) informative collision warnings for younger and older drivers. In line with our previous results, driver BRTs were significantly faster when they were presented with an informative signal as compared to a non-informative signal and a control condition in which no warnings were presented. The results also revealed that the unimodal informative warning was just as effective as the multisensory warning. Intriguingly, older drivers exhibited faster BRTs than younger drivers, and were significantly faster following the presentation of multisensory warning signals. Finally, this study identifies the need to compare new configurations of informative tactile collision warning signals

Crowding by Invisible Flankers

Abstract Background: Human object recognition degrades sharply as the target object moves from central vision into peripheral vision. In particular, one's ability to recognize a peripheral target is severely impaired by the presence of flanking objects, a phenomenon known as visual crowding. Recent studies on how visual awareness of flanker existence influences crowding had shown mixed results. More importantly, it is not known whether conscious awareness of the existence of both the target and flankers are necessary for crowding to occur

Purring Wheel: Thermal and Vibrotactile Notifications on the Steering Wheel

Haptic feedback can improve safety and driving behaviour. While vibration has been widely studied, other haptic modalities have been neglected. To address this, we present two studies investigating the use of uni- and bimodal vibrotactile and thermal cues on the steering wheel. First, notifications with three levels of urgency were subjectively rated and then identified during simulated driving. Bimodal feedback showed an increased identification time over unimodal vibrotactile cues. Thermal feedback was consistently rated less urgent, showing its suitability for less time critical notifications, where vibration would be unnecessarily attention-grabbing. The second study investigated more complex thermal and bimodal haptic notifications comprised of two different types of information (Nature and Importance of incoming message). Results showed that both modalities could be identified with high recognition rates of up to 92% for both and up to 99% for a single type, opening up a novel design space for haptic in-car feedback

Crowding by Invisible Flankers

BACKGROUND: Human object recognition degrades sharply as the target object moves from central vision into peripheral vision. In particular, one's ability to recognize a peripheral target is severely impaired by the presence of flanking objects, a phenomenon known as visual crowding. Recent studies on how visual awareness of flanker existence influences crowding had shown mixed results. More importantly, it is not known whether conscious awareness of the existence of both the target and flankers are necessary for crowding to occur. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that crowding persists even when people are completely unaware of the flankers, which are rendered invisible through the continuous flash suppression technique. Contrast threshold for identifying the orientation of a grating pattern was elevated in the flanked condition, even when the subjects reported that they were unaware of the perceptually suppressed flankers. Moreover, we find that orientation-specific adaptation is attenuated by flankers even when both the target and flankers are invisible. CONCLUSIONS: These findings complement the suggested correlation between crowding and visual awareness. What's more, our results demonstrate that conscious awareness and attention are not prerequisite for crowding

Multisensory aspects of the spatial cuing of driver attention

The primary goal of the empirical research outlined in this thesis was to examine a number of the factors contributing to the design of more ergonomic multisensory warning signals, that is, signals that elicit efficient and effective responses from interface operators under demanding conditions. To achieve this goal, a series of experiments was conducted in order to examine the nature and consequences of the crossmodal links inherent in spatial attention between various different sensory modalities, such as audition, vision, and touch, in an applied setting. In particular, a laboratory-based simulated driving task was used to investigate the effectiveness of various different auditory and vibrotactile cues in orienting a driver's attention to potential emergency driving events seen through the front windscreen or rearview mirror. The results of the first set of auditory spatial cuing experiments highlighted a significant performance advantage when the target driving events occurred in the cued, rather than the uncued, direction, with the biggest benefits being seen following spatially-predictive auditory or verbal cues. The second set of vibrotactile spatial cuing experiments demonstrated the potential utility of vibrotactile warning signals for presenting spatial information to car drivers, and the results were successfully replicated in a study using a high-fidelity driving simulator. The third set of experiments, incorporating an orthogonal task design, were conducted in order to examine the mechanisms responsible for the advantageous spatial cuing effects reported in the earlier experiments. Taken together, the results demonstrated that while directional congruency between a warning signal and target driving event may be sufficient to facilitate performance due to the priming of the appropriate response, attentional facilitation (i.e., perceptual enhancement) typically requires the co-location of the cue and target within the same functional region of space. In sum, this thesis demonstrates the potential value of approaching the design of effective multisensory warning signals for human operators by studying the information processing mechanisms in the human brain. The findings outlined here add to the literature concerning the brain's differential representation of stimuli presented in peripersonal as opposed to extrapersonal space. Further experimental chapters detail experiments that examined verbal directional cuing, olfactory cuing, and crossmodal interactions in virtual haptic environments

Multisensory aspects of the spatial cuing of driver attention

The primary goal of the empirical research outlined in this thesis was to examine a number of the factors contributing to the design of more ergonomic multisensory warning signals, that is, signals that elicit efficient and effective responses from interface operators under demanding conditions. To achieve this goal, a series of experiments was conducted in order to examine the nature and consequences of the crossmodal links inherent in spatial attention between various different sensory modalities, such as audition, vision, and touch, in an applied setting. In particular, a laboratory-based simulated driving task was used to investigate the effectiveness of various different auditory and vibrotactile cues in orienting a driver's attention to potential emergency driving events seen through the front windscreen or rearview mirror. The results of the first set of auditory spatial cuing experiments highlighted a significant performance advantage when the target driving events occurred in the cued, rather than the uncued, direction, with the biggest benefits being seen following spatially-predictive auditory or verbal cues. The second set of vibrotactile spatial cuing experiments demonstrated the potential utility of vibrotactile warning signals for presenting spatial information to car drivers, and the results were successfully replicated in a study using a high-fidelity driving simulator. The third set of experiments, incorporating an orthogonal task design, were conducted in order to examine the mechanisms responsible for the advantageous spatial cuing effects reported in the earlier experiments. Taken together, the results demonstrated that while directional congruency between a warning signal and target driving event may be sufficient to facilitate performance due to the priming of the appropriate response, attentional facilitation (i.e., perceptual enhancement) typically requires the co-location of the cue and target within the same functional region of space. In sum, this thesis demonstrates the potential value of approaching the design of effective multisensory warning signals for human operators by studying the information processing mechanisms in the human brain. The findings outlined here add to the literature concerning the brain's differential representation of stimuli presented in peripersonal as opposed to extrapersonal space. Further experimental chapters detail experiments that examined verbal directional cuing, olfactory cuing, and crossmodal interactions in virtual haptic environments.</p

Using peripersonal warning signals to orient a driver's gaze.

OBJECTIVE: We report a series of three experiments designed to assess the relative speed with which people can initiate speeded head-orienting responses following the presentation of spatial warning signals. BACKGROUND: Recent cognitive neuroscience findings have shown that the human brain tends to treat stimuli occurring in peripersonal space as being somehow more behaviorally relevant and attention demanding than stimuli occurring in extrapersonal space. These brain mechanisms may be exploited in the design of warning signals. METHOD: Experiment 1 assessed the effectiveness of various different unisensory warning signals in eliciting a head-turning response to look at the potential source of danger requiring participants' immediate attention; Experiment 2 assessed the latency of a driver's responses to events occurring in the cued direction; Experiment 3 assessed the relative effectiveness of various warning signals in reorienting a person's gaze back to a central driving task while he or she was distracted by a secondary task. RESULTS: The results show that participants initiated head-turning movements and made speeded discrimination or braking responses significantly more rapidly following the presentation of a close rear auditory warning signal than following the presentation of either a far frontal auditory warning signal, a vibrotactile warning signal presented to their waist, or a peripheral visual warning signal. CONCLUSION: These results support the claim that the introduction of peripersonal warning signals results in a significant performance advantage relative to traditionally designed warnings. APPLICATION: Warning systems that have been designed around the constraints of the human brain offer great potential in the future design ofmultisensory interfaces

Affective multisensory driver interface design

The last decade has seen a surge of interest in the development of affective driver interfaces designed to enhance driver safety and convey useful information to the driver. These technological advances have brought about changes in the ambient driving environment and clearly have the potential to enhance the driving experience in the years to come. This review provides an overview of existing research approaches to the study of these innovations. Other possible psychophysiological approaches to affective driver interface design, such as via mood induction procedures, are also discussed. Finally, we highlight the likely impact of the latest findings on the topic of multisensory integration research for the future design of affective driver interfaces. In particular, we look at how multisensory driver interfaces may evolve in the future, and assess the likely impact of multisensory warning signals that have been designed specifically to trigger the brain's defensive circuits. Copyright © 2013 Inderscience Enterprises Ltd

Verbal interface design: Do verbal directional cues automatically orient visual spatial attention?

The last few years have seen a rapid growth of interest in the use of verbal information displays in many applied interface settings. However, to date, it is unclear what effect the presentation of verbal cues, such as the words 'left' or 'right', has on the spatial distribution of an interface operator's attention. In the present study, we addressed this issue by investigating whether centrally-presented spatially-nonpredictive verbal directional cues elicit an automatic shift of visual spatial attention in the direction indicated by the cue. Participants performed a digit discrimination task for targets presented on either the left or right. Prior to target presentation, the directional word cues 'left' or 'right' were presented auditorily or visually from the centre of the display at cue-target stimulus onset asynchronies (SOAs) of 200, 400, or 600 ms. Visual discrimination performance was assessed both under conditions where the target digits were unmasked (auditory and visual cuing), and when the targets were masked (auditory cuing only). The results showed that unmasked visual target discrimination performance was facilitated on the cued (relative to the uncued) side at the shortest SOA following visual cuing, but was unaffected by auditorily-presented directional cues. Interestingly, our results also indicated improved visual sensitivity on the auditorily-cued side in the masked target condition. These findings are discussed in relation to previous laboratory-based and applied symbolic cuing studies that have investigated the consequences of the presentation of arrow, gaze direction, and/or head orientation directional cues on the spatial distribution of attention. © 2005 Elsevier Ltd. All rights reserved