Yusuke Yamani

Visual Search Asymmetries in Heavy Clutter Implications for Display Design

Objective: An experiment aimed to test whether design of symbology to produce visual search asymmetries might facilitate target detection in cluttered displays. Background: A visual search asymmetry exists between two stimuli when a target of one type is found efficiently among distractors of the second type but a target of the second type is found with difficulty among distractors of the first type. Asymmetries have generally been studied within relatively sparse displays. In the present study, the authors tested whether an asymmetry driven by stimulus familiarity persists within heavily cluttered imagery. Method: In this study, 10 participants performed a visual search task using stimuli (canonical vs. reversed Ns) known to produce a search asymmetry. Search stimuli were embedded within geospatial images containing either low or high levels of clutter. A decision theoretic index of sensitivity served as the dependent measure. Results: The search asymmetry was robust against the presence of heavy display clutter. Specifically, sensitivity was greater when the target was a reversed N rather than an N, and this pattern remained within cluttered displays. Time-accuracy analysis revealed that the search asymmetry increased the rate of information accumulation roughly equally within low- and high- clutter images. Conclusion: Search asymmetries are robust against heavy, spatially continuous visual clutter. Application: Design of display symbology to produce visual search asymmetries can offset the costs of visual clutter, maximizing detectability of task-critical information in complex displays.

Visual Search Asymmetries Within Color-Coded and Intensity-Coded Displays

Color and intensity coding provide perceptual cues to segregate categories of objects within a visual display, allowing operators to search more efficiently for needed information. Even within a perceptually distinct subset of display elements, however, it may often be useful to prioritize items representing urgent or task-critical information. The design of symbology to produce search asymmetries (Treisman & Souther, 1985) offers a potential technique for doing this, but it is not obvious from existing models of search that an asymmetry observed in the absence of extraneous visual stimuli will persist within a complex color- or intensity-coded display. To address this issue, in the current study we measured the strength of a visual search asymmetry within displays containing color- or intensity-coded extraneous items. The asymmetry persisted strongly in the presence of extraneous items that were drawn in a different color (Experiment 1) or a lower contrast (Experiment 2) than the search-relevant items, with the targets favored by the search asymmetry producing highly efficient search. The asymmetry was attenuated but not eliminated when extraneous items were drawn in a higher contrast than search-relevant items (Experiment 3). Results imply that the coding of symbology to exploit visual search asymmetries can facilitate visual search for high-priority items even within color- or intensity-coded displays.

Trust and the Compliance–Reliance Paradigm: The Effects of Risk, Error Bias, and Reliability on Trust and Dependence

Objective: This study provides a theoretical link between trust and the compliance–reliance paradigm. We propose that for trust mediation to occur, the operator must be presented with a salient choice, and there must be an element of risk for dependence. Background: Research suggests that false alarms and misses affect dependence via two independent processes, hypothesized as trust in signals and trust in nonsignals. These two trust types manifest in categorically different behaviors: compliance and reliance. Method: Eighty-eight participants completed a primary flight task and a secondary signaling system task. Participants evaluated their trust according to the informational bases of trust: performance, process, and purpose. Participants were in a high- or low-risk group. Signaling systems varied by reliability (90%, 60%) within subjects and error bias (false alarm prone, miss prone) between subjects. Results: False-alarm rate affected compliance but not reliance. Miss rate affected reliance but not compliance. Mediation analyses indicated that trust mediated the relationship between false-alarm rate and compliance. Bayesian mediation analyses favored evidence indicating trust did not mediate miss rate and reliance. Conditional indirect effects indicated that factors of trust mediated the relationship between false-alarm rate and compliance (i.e., purpose) and reliance (i.e., process) but only in the high-risk group. Conclusion: The compliance–reliance paradigm is not the reflection of two types of trust. Application: This research could be used to update training and design recommendations that are based upon the assumption that trust causes operator responses regardless of error bias.

Sequential in-vehicle glance distributions: an alternative approach for analyzing glance data

Objective: The aim of this study was to illustrate how a consideration of glance sequences to in-vehicle tasks and their associated distributions can be informative. Background: The rapid growth in the number of nomadic technologies and in-vehicle devices has the potential to create complex, visually intensive tasks for drivers that may incur long in-vehicle glances. Such glances place drivers at increased risk of a motor vehicle crash. Method: We used eye-glance data from a study of distraction training programs to examine the change in glance duration distributions across consecutive glances during the performance of various in-vehicle tasks. Results: The sequential analysis across trained and untrained drivers showed that the proportion of late-sequence glances longer than a 2-s threshold among untrained drivers was almost double the number of such glances for the trained drivers, that the third and later glances were particularly problematic, and that training reduced the proportion of early- and later-sequence glances. Conclusion: Examining how the duration of off-road glances varies as a function of their order in a sequence of glances and the visual demands of the task can offer important insights into the change in the distracting potential of in-vehicle tasks across glances and the effects of training. Application: The sequential analysis of in-vehicle glance data can be useful for researchers and practitioners and has implications for the development and evaluation of training programs as well as for task and interface design.

Spatial interference between attended items engenders serial visual processing

A pair of experiments investigated the architecture of visual processing, parallel versus serial, across high and low levels of spatial interference in a divided attention task. Subjects made speeded judgments that required them to attend to a pair of color-cued objects among gray filler items, with the spatial proximity between the attended items varied to manipulate the strength of interference between attended items. Systems factorial analysis (Townsend & Nozawa, Journal of Mathematical Psychology 39:321-359, 1995) was used to identify processing architecture. Experiment 1, using moderately dense displays, found evidence of parallel processing whether attended objects were in low or high proximity to one another. Experiment 2, using higher-density displays, found evidence of parallel selection when attended stimuli were widely separated but serial processing when they were in high proximity. Divided visual attention can operate in parallel under conditions of low or moderate spatial interference between selected items, but strong interference engenders serial processing.

Age-related differences in vehicle control and eye movement patterns at intersections: older and middle-aged drivers

Older drivers are at increased risk of intersection crashes. Previous work found that older drivers execute less frequent glances for detecting potential threats at intersections than middle-aged drivers. Yet, earlier work has also shown that an active training program doubled the frequency of these glances among older drivers, suggesting that these effects are not necessarily due to age-related functional declines. In light of findings, the current study sought to explore the ability of older drivers to coordinate their head and eye movements while simultaneously steering the vehicle as well as their glance behavior at intersections. In a driving simulator, older (M = 76 yrs) and middle-aged (M = 58 yrs) drivers completed different driving tasks: (1) travelling straight on a highway while scanning for peripheral information (a visual search task) and (2) navigating intersections with areas potential hazard. The results replicate that the older drivers did not execute glances for potential threats to the sides when turning at intersections as frequently as the middle-aged drivers. Furthermore, the results demonstrate costs of performing two concurrent tasks, highway driving and visual search task on the side displays: the older drivers performed more poorly on the visual search task and needed to correct their steering positions more compared to the middle-aged counterparts. The findings are consistent with the predictions and discussed in terms of a decoupling hypothesis, providing an account for the effects of the active training program.

Navigating Intersections: Examining Age-related Differences in Visual Scanning on a Driving Simulator

Older experienced drivers are at a greater risk of fatal crash involvement at intersections than middle-aged experienced drivers. The present cross-sectional study asked older and middle-aged drivers to maneuver various types of intersections (left turn at a 4-way intersection, right turn at a T-intersection and straight through an intersection) in a driving simulator and measured their frequency of glances towards latent and materializing hazards. Results replicate and extend the original findings by Romoser and Fisher (2009). First, the older drivers executed a smaller proportion of primary glances and secondary glances towards target zones where a latent or materializing hazard occurs than middle-aged experienced drivers. Second, older drivers who executed fewer glances toward the hazard were more likely to crash while navigating intersections. These findings provide further evidence for age-related differences in visual scanning for information critical to road safety at intersections. From a practical standpoint, practitioners can utilize better remedial measures in lieu of these age-specific shortcomings.

Workload Capacity A Response Time–Based Measure of Automation Dependence

Objective An experiment used the workload capacity measure C(t) to quantify the processing efficiency of human–automation teams and identify operators’ automation usage strategies in a speeded decision task. Background Although response accuracy rates and related measures are often used to measure the influence of an automated decision aid on human performance, aids can also influence response speed. Mean response times (RTs), however, conflate the influence of the human operator and the automated aid on team performance and may mask changes in the operator’s performance strategy under aided conditions. The present study used a measure of parallel processing efficiency, or workload capacity, derived from empirical RT distributions as a novel gauge of human–automation performance and automation dependence in a speeded task. Method Participants performed a speeded probabilistic decision task with and without the assistance of an automated aid. RT distributions were used to calculate two variants of a workload capacity measure, COR(t) and CAND(t). Results Capacity measures gave evidence that a diagnosis from the automated aid speeded human participants’ responses, and that participants did not moderate their own decision times in anticipation of diagnoses from the aid. Conclusion and Application Workload capacity provides a sensitive and informative measure of human–automation performance and operators’ automation dependence in speeded tasks.

Simulator Evaluation of an Integrated Road Safety Training Program

Younger drivers aged 16 to 18 show disproportionately higher crash rates than middle-aged drivers, partly due to a decrement in their abilities to anticipate latent hazards, mitigate hazards and maintain attention on the forward roadway. Training programs have been developed to train novice drivers on each of the specific skills, hazard anticipation (RAPT), hazard mitigation (ACT), and attention maintenance (FOCAL). The current study both measures the effectiveness of a novel integrated training program (SAFE-T) that takes only a third as long to complete as do the three individual training programs and determines if integrating the training of all three higher cognitive skills will yield results comparable to the existing programs. The results indicated that drivers in the SAFE-T-trained group were significantly more likely to anticipate hazards, quicker and more effective at responding to hazards, and more likely to keep glance durations under a critical threshold of 2 seconds as compared to drivers in the placebo-trained group. Moreover, the results suggest that the SAFE-T training program can effectively reduce the time of the overall training and maintain effect sizes comparable to those of the previous programs.

Latent Hazard Anticipation in Young Drivers: Review and Meta-Analysis of Training Studies

Young drivers are overrepresented in motor vehicle crashes, and are shown to be poorer at anticipating potential threats on the roadway compared with their more experienced peers. Literature demonstrates the effectiveness of driver training programs at improving young drivers’ latent hazard anticipation performance. Various hazard anticipation training studies have been undertaken on different population demographics using different training scenario presentation modes and multiple evaluation testbeds. These error-based feedback training programs (3M) allow trainees to make a mistake, show them how to mediate the mistake, and provide an opportunity to master the target skills. The current meta-analytical review focused on 19 peer-reviewed training studies that utilized eye movements to measure improvements in drivers’ latent hazard anticipation performance following training. The role of four moderating factors (mode of delivery – PC-based or non PC-based; presentation of training – egocentric or exocentric; method of evaluation – on-road or driving simulator; and age of sample – teen novices aged 16–17 or young drivers aged 18–21) on the training effects were explored. Overall, the current meta-analysis suggest that: (a) superficial improvements in training programs does not necessarily further improve the drivers’ latent hazard anticipation; (b) drivers who completed a training program with both egocentric and exocentric training views achieved greater levels of latent hazard anticipation performance than those who completed a training program that contained either view, but not both; and (c) the effect sizes of the 3M-based training programs on latent hazard anticipation were greater for drivers aged 18–21 years than drivers aged 16–17.