Abstract: Driver inattention has been identified as one of the leading causes for car accidents. The problem of distraction while driving is likely to worsen, partly due to increasingly complex in-car technologies. However, intelligent transport systems are being developed to assist drivers and to ensure a safe road environment.
One approach to the design of ergonomic automobile systems is to integrate our understanding of the human information processing systems into the design process. This book aims to further the design of ergonomic multisensory interfaces using research from the fast-growing field of cognitive neuroscience. It focuses on two aspects of driver information-processing in particular: multisensory interactions and the spatial distribution of attention in driving.
The Multisensory Driver provides interface design guidelines together with a detailed review of current cognitive neuroscience and behavioural research in multisensory human perception, which will help the development of ergonomic interfaces. The discussion on spatial attention is particularly relevant for car interface designers, but it will also appeal to cognitive psychologists interested in spatial attention and the applications of these theoretical research findings. Giving a detailed description of a cohesive series of psychophysical experiments on multisensory warning signals, conducted in both laboratory and simulator settings, this book provides an approach for those in the engineering discipline who wish to test their systems with human observers.
Notes: Introduction; Driven to distraction; Driven to listen; The auditory spatial cuing of driver attention; The vibrotactile spatial cuing of driver attention; The multisensory perceptual versus decisional facilitation of driving; The multisensory spatial cuing of driver attention; Conclusions; References; Index
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.
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.
Abstract: We report a study designed to investigate the effectiveness of task-irrelevant unimodal and bimodal audiotactile stimuli in capturing a person's spatial attention away from a highly perceptually demanding central rapid serial visual presentation (RSVP) task. In "Experiment 1", participants made speeded elevation discrimination responses to peripheral visual targets following the presentation of auditory stimuli that were either presented alone or else were paired with centrally presented tactile stimuli. The results showed that the unimodal auditory stimuli only captured spatial attention when participants were not performing the RSVP task, while the bimodal audiotactile stimuli did not result in any performance change in any of the conditions. In "Experiment 2", spatial auditory stimuli were either presented alone or else were paired with a tactile stimulus presented from the same direction. In contrast to the results of "Experiment 1", the bimodal audiotactile stimuli were especially effective in capturing participants' spatial attention from the concurrent RSVP task. These results therefore provide support for the claim that auditory and tactile stimuli should be presented from the same direction if they are to capture attention effectively. Implications for multisensory warning signal design are discussed.
Abstract: 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 of multisensory interfaces.
Abstract: The last few years have seen many exciting developments in the area of tactile and multisensory interface design. One of the most rapidly-moving practical application areas for these findings is in the development of warning signals and information displays for drivers. For instance, tactile displays can be used to awaken sleepy drivers, to capture the attention of distracted drivers, and even to present more complex information to drivers who may be visually-overloaded. This review highlights the most important potential costs and benefits associated with the use of tactile and multisensory information displays in a vehicular setting. Multisensory displays that are based on the latest cognitive neuroscience research findings can capture driver attention significantly more effective than their unimodal (i.e., tactile) counterparts. Multisensory displays can also be used to transmit information more efficiently, as well as to reduce driver workload. Finally, we highlight the key research questions currently awaiting further research, including questions such as: Are tactile warning signals really intuitive? Are there certain regions of the body (or in the space surrounding the body) where tactile/multisensory warning signals are particularly effective? To what extent is the spatial coincidence and temporal synchrony of the individual sensory signals critical to determining the effectiveness of multisensory displays? And, finally, how does the issue of compliance vs. reliance (or the 'cry wolf' phenomenon associated with the presentation of signals that are perceived as false alarms) influence the effectiveness of tactile and/or multisensory warning signals?
Abstract: This article reviews various different approaches to the design of unimodal and multisensory warning signals, in particular warning signals for use in alerting drivers to potentially dangerous situations. The design of optimal warning signals that are maximally effective in terms of the limitations that constrain human information processing are discussed in light of the latest findings emerging from cognitive neuroscience research. A new approach to the design of multisensory warning signals, involving the presentation of warning signals in different regions of space around a driver, is then critically examined.
Abstract: We assessed the influence of multisensory interactions on the exogenous orienting of spatial attention by comparing the ability of auditory, tactile, and audiotactile exogenous cues to capture visuospatial attention under conditions of no perceptual load versus high perceptual load. In Experiment 1, participants discriminated the elevation of visual targets preceded by either unimodal or bimodal cues under conditions of either a high perceptual load (involving the monitoring of a rapidly presented central stream of visual letters for occasionally presented target digits) or no perceptual load (when the central stream was replaced by a fixation point). All of the cues captured spatial attention in the no-load condition, whereas only the bimodal cues captured visuospatial attention in the high-load condition. In Experiment 2, we ruled out the possibility that the presentation of any changing stimulus at fixation (i.e., a passively monitored stream of letters) would eliminate exogenous orienting, which instead appears to be a consequence of high perceptual load conditions (Experiment 1). These results demonstrate that multisensory cues capture spatial attention more effectively than unimodal cues under conditions of concurrent perceptual load.
Abstract: Objective: A driving simulator study was conducted in order to assess the relative utility of unimodal auditory, unimodal vibrotactile, and combined audiotactile (i.e., multisensory) in-car warning signals to alert and inform drivers of likely front-to-rear-end collision events in a situation modeled on real-world driving. Background: The implementation of nonvisual in-car warning signals may have important safety implications in lessening any visual overload during driving. Multisensory integration can provide synergistic facilitation effects. Method: The participants drove along a rural road in a car-following scenario in either the presence or absence of a radio program in the background. The brake light signals of the lead vehicle were also unpredictably either enabled or disabled on a trial-by-trial basis. Results: The results showed that the participants initiated their braking responses significantly more rapidly following the presentation of audiotactile warning signals than following the presentation of either unimodal auditory or unimodal vibrotactile warning signals. Conclusion: Multisensory warning signals offer a particularly effective means of capturing driver attention in demanding situations such as driving. Application: The potential value of such multisensory in-car warning signals is explained with reference to recent cognitive neuroscience research.
Abstract: In the present study, we examined whether the 'Mozart effect' would influence participants' temporal attention using a visual attentional blink (AB) task that provides a reliable measure of the temporal dynamics of visual attention. The 'Mozart effect' refers to the specific claim that listening to Mozart's Sonata for Two Pianos in D Major, K.448 can improve the performance in spatio-temporal tasks. Participants had to try and identify two target digits (in their correct order of presentation) presented amongst a stream of distractor letters in three different conditions (presented in separate blocks of trials): while listening to the Mozart sonata played normally, while listening to the same Mozart sonata played in reverse, and while in silence. The results showed that the participants were able to detect the second target (T2) significantly more accurately (given the correct detection of the first target, T1) in the AB stream when the Mozart sonata was played normally than in either of the other two conditions. Possible explanations for the differential effects of Mozart's music being played normally and in reverse and potential confounds in previous studies reporting a facilitatory 'Mozart effect' are discussed. Our results therefore provide the first empirical demonstration supporting the existence of a purely temporal component to the 'Mozart effect' using a non-spatial visual AB task.
Abstract: Does the perceived location of tactile stimuli presented on the torso depend on the orientation of our heads with respect to our bodies? An experiment is reported that was designed to assess whether the subjective perception of tactile stimuli on the torso changes as people turn their heads in different directions. Our participants used a scale presented on a computer monitor to indicate the perceived position of vibrotactile stimuli presented to one of eight different positions around the frontal side of their waist while they either looked straight ahead, turned their head to the left, or else turned their head to the right. The results showed that the perceived location of tactile stimuli was systematically influenced by head orientation. In particular, the perceived location of the tactile stimuli shifted away from their actual position in the direction opposite to the direction of the participant's head turn. Our results also revealed a systematic decline in the accuracy of tactile localization as a function of the physical distance of the tactile stimuli from the participant's navel. These results echo related findings in the auditory domain where it has been shown that changes in eye position affect auditory lateralization. Our results also have important implications for the design of tactile displays for presenting directional information in a variety of real-world applications.
Abstract: 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.
Abstract: The authors report an experiment in which twenty-five participants discriminated force vectors presented along five directions (up, left, right, diagonally up left, diagonally up right). The force vectors were presented with a three degree-of-freedom forcefeedback device. A three-interval one-up three-down adaptive procedure was used. The five reference force-direction conditions were presented in randomly interleaved order. The results show an average force-direction discrimination threshold of 33° regardless of the reference-force direction. Position data recorded at a nominal sampling rate of 200 Hz revealed a 10.1 mm average displacement of the fingertip between the start and end positions in a trial. The average maximum deviation from the starting position within a trial was 21.3 mm. We conclude that the resolution with which people can discriminate force direction is not dependent on the direction of the force per se. These results are useful for designers of haptic virtual environments.
Abstract: Previous research has shown that the presentation of spatially predictive auditory and vibrotactile warning signals can facilitate driver responses to driving events seen through the windscreen or rearview mirror. The present study investigated whether this facilitation reflects the priming of the appropriate response (i.e. braking vs. accelerating) or an attentional cuing effect (i.e. a perceptual benefit that facilitates subsequent behavioural responding). In the experiments reported here, participants had to discriminate the colour of a number plate (red vs. blue) following the presentation of either spatially predictive vibrotactile (experiment 1) or auditory (experiment 2) warning signals that indicated the likely location (front or back) of the visual target, while simultaneously performing a highly attention-demanding rapid serial visual presentation task. Numberplate discrimination performance was facilitated following the presentation of valid auditory cues, but not following the presentation of equally informative vibrotactile cues. The use of an orthogonal spatial cuing design enabled with us to rule out of a potential response priming account of these data. The results suggest that whilst directional congruency between a warning signal and a target event may be sufficient to facilitate performance due to the priming of the appropriate response, attentional facilitation effects may also require the co-location of the cue and target within the same functional region of space.
Abstract: Despite a wealth of literature on discrimination thresholds for displacement, force magnitude, stiffness, and viscosity, there is currently a lack of data on our ability to discriminate force directions. Such data are needed in designing haptic rendering algorithms where force direction, as well as force magnitude, are used to encode information such as surface topography. Given that haptic information is typically presented in addition to visual information in a data perceptualization system, it is also important to investigate the extent to which the congruency of visual information affects force-direction discrimination. In this article, the authors report an experiment on the discrimination threshold of force directions under the three display conditions of haptics alone (H), haptics plus congruent vision (HVcong), and haptics plus incongruent vision (HVincong). Average force-direction discrimination thresholds were found to be 18.4°, 25.6°, and 31.9° for the HVcong, H and HVincong conditions, respectively. The results show that the congruency of visual information significantly affected haptic discrimination of force directions, and that the force-direction discrimination thresholds did not seem to depend on the reference force direction. The implications of the results for designing haptic virtual environments, especially when the numbers of sensors and actuators in a haptic display do not match, are discussed.
Abstract: This study was designed to investigate the possibility that driver responses to potential front-to-rear-end collision situations could be facilitated by implementing vibrotactile warning signals that indicate the likely direction of the potential collision. In a car following scenario in a driving simulator, participants drove along a rural road while trying to maintain a safe headway distance to the lead car using a visual distance display. Participants had to respond as quickly as possible to the sudden deceleration of the lead car which had its brake lights disabled, either with or without vibrotactile cues (presented in different experimental blocks). The results demonstrated significantly faster braking responses and larger safety margins when the vibrotactile warning signal was presented than when it was not. These findings demonstrate the effectiveness of vibrotactile cues in helping drivers to orient their spatial attention in the appropriate direction. Our results add to a growing body of empirical evidence highlighting the potential benefits of using "intuitive" vibrotactile in-car displays, in this case, to alert drivers to potential collisions and to provide time-critical directional information.
Abstract: We investigated the differential effects of olfactory stimulation on dual-task performance under conditions of varying task difficulty. Participants detected visually presented target digits from amongst a stream of visually presented distractor letters in a rapid serial visual presentation (RSVP) task. At the same time, participants also made speeded discrimination responses to vibrotactile stimuli presented on the front or back of their torso. The response mapping was either compatible or incompatible (i.e., lifting their toes for front vibrations and their heel for back vibrations, or vice versa, respectively). Synthetic peppermint odor or clean air (control) was delivered periodically for 35 s in every 315 s. The results showed a significant performance improvement in the presence of peppermint odor (as compared to air) when the response mapping was incompatible (i.e., in the difficult task) but not in the compatible condition (i.e., in the easy task). Our results provide the first empirical demonstration that olfactory stimulation can facilitate tactile performance, and also highlight the potential modulatory role of task-difficulty in odor-induced task performance facilitation.
Abstract: We report two experiments designed to investigate the potential use of vibrotactile warning signals to present spatial information to car drivers. Participants performed an attention-demanding rapid serial visual presentation (RSVP) monitoring task. Meanwhile, whenever they felt a vibrotactile stimulus presented on either their front or back, they had to check the front and the rearview mirror for the rapid approach of a car, and brake or accelerate accordingly. We investigated whether speeded responses to potential emergency driving situations could be facilitated by the presentation of spatially-predictive (80% valid; Experiment 1) or spatially-nonpredictive (50% valid; Experiment 2) vibrotactile cues. Participants responded significantly more rapidly following both spatially-predictive and spatially-nonpredictive vibrotactile cues from the same rather than the opposite direction as the critical driving events. These results highlight the potential utility of vibrotactile warning signals in automobile interface design for directing a driver’s visual attention to time-critical events or information.
Abstract: This study was designed to assess the potential benefits of using spatial auditory warning signals in a simulated driving task. In particular, the authors assessed the possible facilitation of responses (braking or accelerating) to potential emergency driving situations (the rapid approach of a car from the front or from behind) seen through the windshield or the rearview mirror. Across 5 experiments, the authors assessed the efficacy of nonspatial-nonpredictive (neutral), spatially nonpredictive (50% valid), and spatially predictive (80% valid) car horn sounds, as well as symbolic predictive and spatially presented symbolic predictive verbal cues (the words "front" or "back") in directing the participant's visual attention to the relevant direction. The results suggest that spatially predictive semantically meaningful auditory warning signals may provide a particularly effective means of capturing attention.
