Toward user-centered assistive technologies for aging in place with cognitive impairment: a survey.

PURPOSE: To reduce the burden of Alzheimer's disease, the use of assistive technologies for patients and their informal caregivers is considered essential. However, these technologies are made as "one size fits all" instead of being tailored to accommodate people with varying degrees of cognitive impairment and those with diverse races/ethnicities. Thus, the aim of this survey was to determine whether the types of assistance needed most, and the technology used by those with cognitive impairment differed by race (White/non-Hispanics, Black or African Americans, and Hispanic/Latinos or Puerto Ricans) and severity of dementia (mild, moderate, severe). RESEARCH DESIGN AND METHODS: One hundred and eighty informal caregivers of people with different levels of severity of cognitive impairment and several different races/ethnicities filled out an online survey regarding assistance needed and technologies used. RESULTS: The results show that racial minorities considered the needs for assistance with Basic Activities of Daily Living as more important compared to White/non-Hispanics with mild dementia. Furthermore, Hispanic/Latinos or Puerto Ricans and White/non-Hispanics with severe dementia were shown to use technology that is designed to help with Instrumental Activities of Daily Living more than those with moderate dementia. Lastly, during COVID-19, devices to assist with walking, preparing meals and personal hygiene have been used significantly more by White/non-Hispanics with severe dementia compared to Hispanic/Latinos or Puerto Ricans. CONCLUSION: The results point to the need to design for those with severe dementia, regardless of race, and should focus on addressing needs related to both Instrumental and Basic Activities of Daily Living.

Developers of assistive technology should consider designing technology that can accommodate all severity levels of cognitive impairment.More research is needed to determine the usability of assistive technology that is designed for those with cognitive impairments.

Effects of task demands on tactile vigilance.

A performance decline during sustained monitoring of unpredictable and occasional signals, the vigilance decrement, has been studied mostly in the visual and auditory modalities, but a tactile vigilance decrement also has been observed and has been associated with high perceived workload, declines in sensitivity and task engagement, and increases in distress. The primary aim of the current study was to determine whether task demands affect the vigilance decrement in the tactile modality and whether the effects are similar to those observed in the auditory and visual modalities. Participants completed a 40-min vigil in which they monitored vibrotactile stimuli generated by a tactor and had to discriminate between durations of bursts of vibrations. Task demand was varied by including low and high event rates. Although correct detections decreased over time (vigilance decrement) and sensitivity was greater for the slower event rate, there was not an interaction between period of watch and event rate. There also were no differences in workload and stress between event rates. Results indicate that mean performance in tactile vigilance tasks is negatively impacted by increases in event rate, indicating that a typical source of task demand known to affect visual and auditory vigilance also affects tactile vigilance. Results could be explained by either an underload or overload theory of the vigilance decrement.

Does the Size-Arrival Effect Occur With an Active Collision-Avoidance Task in an Immersive 3D Virtual Reality Environment?

OBJECTIVE: Determine whether the size-arrival effect (SAE) occurs with immersive, 3D visual experiences and active collision-avoidance responses. BACKGROUND: When a small near object and a large far object approach the observer at the same speeds, the large object appears to arrive before the small object, known as the size-arrival effect (SAE), which may contribute to crashes between motorcycles and cars. Prior studies of the SAE were limited because they used two dimensional displays and asked participants to make passive judgments. METHOD: Participants viewed approaching objects using a virtual reality (VR) headset. In an active task, participants ducked before the object hit them. In a passive prediction-motion (PM) judgment, the approaching object disappeared, and participants pressed a button when they thought the object would hit them. In a passive relative TTC judgment, participants reported which of two approaching objects would reach them first. RESULTS: The SAE occurred with the PM and relative TTC tasks but not with the ducking task. The SAE can occur in immersive 3D environments but is limited by the nature of the task and display. APPLICATION: Certain traffic situations may be more prone to the SAE and have higher risk for collisions. For example, in left-turn scenarios (e.g., see Levulis, 2018), drivers make passive judgments when oncoming vehicles are far and optical expansion is slow, and binocular disparity putatively is ineffective. Collision-avoidance warning systems may be needed more in such scenarios than when vehicles are near and drivers' judgments of TTC may be more accurate (DeLucia, 2008).

Factors That Affect Drivers' Perception of Closing and an Immediate Hazard.

OBJECTIVE: To measure the looming threshold for when drivers perceive closing and an immediate hazard and determine what factors affect these thresholds. BACKGROUND: Rear-end collisions are a common type of crash. One key issue is determining when drivers first perceive they need to react. The looming threshold for closing and an immediate hazard are critical perceptual thresholds that reflect when drivers perceive they need to react. METHOD: Two driving simulator experiments examined whether engaging in a cell phone conversation and whether the complexity of the roadway environment affect these thresholds for the perception of closing and immediate hazard. Half of the participants engaged in a cognitive task, the last letter task, to emulate a cell phone conversation, and all participants experienced both simple and complex roadway environments. RESULTS: Drivers perceived an immediate hazard later when engaged in a cell phone conversation than when not engaged in a conversation but only when the driving task was relatively less demanding (e.g., simple roadway, slow closing velocity). Compared to simple scenes, drivers perceived closing and an immediate hazard later for complex scenes but only when closing velocity was 30 mph (48.28 km/h) or greater. CONCLUSION: Cell phone conversation can affect when drivers perceive an immediate hazard when the roadway is less demanding. Roadway complexity can affect when drivers perceive closing and an immediate hazard when closing velocity is high. APPLICATION: Results can aid accident analysis cases and the design of driving automation systems by suggesting when a typical driver would respond.

Modality Changes in Vigilance Displays: Further Evidence of Supramodal Resource Depletion in Vigilance.

OBJECTIVE: This study was designed to evaluate the effects of a modality change on vigilance performance to determine whether depletion of modality-specific resources contributes to the vigilance decrement. BACKGROUND: Resource theory accounts for the vigilance decrement by arguing that the demands of vigilance deplete limited information processing resources. Research indicates that both supramodal and modality-specific resources are involved in vigilance, but it is unclear whether the vigilance decrement is due to depletion of supramodal resources, modality-specific resources, or both. If depletion of modality-specific resources contributes to the decrement, changing the modality of a vigilance display should improve vigilance performance after a decrement. METHOD: Participants completed a 50-min vigilance task beginning in either the visual modality or the auditory modality. After 40-min, half of the participants experienced a sudden transition to the other modality; the remaining participants did not experience a modality change. RESULTS: Performance declined over time and was generally superior in the auditory modality. Changing modality from visual to auditory increased correct detections, whereas changing from auditory to visual decreased correct detections. Both types of modality change were associated with an increase in false alarms, and neither had an effect on workload or stress. CONCLUSION: Supramodal resource depletion, rather than modality-specific resource depletion, is the most likely explanation for the vigilance decrement that can be derived from resource theory. APPLICATION: Modality changes are not likely to counteract the vigilance decrement and may actually increase false alarm errors. Countermeasure development should involve identification of depleted supramodal resources.

Driver Vigilance Decrement is More Severe During Automated Driving than Manual Driving.

OBJECTIVE: The present study compared the performance, workload, and stress associated with driver vigilance in two types of vehicle: a traditional, manually operated vehicle, and a partially automated vehicle. BACKGROUND: Drivers of partially automated vehicles must monitor for hazards that constitute automation failures and the need for human intervention, but recent research indicates that a driver's ability to do so declines as a function of time. That research lacked a comparison measure of driving without vehicle automation, so it is unknown to what degree these effects are specific symptoms of monitoring the roadway during an automated drive. Drivers in manual control of their vehicle must similarly monitor for hazards and may suffer similar vigilance decrements. METHOD: Participants completed a simulated 40-minute drive while monitoring for hazards. Half of participants completed the drive with an automated driving system that maintained speed and lane position; the remaining half manually controlled the vehicle's speed and lane position. RESULTS: Driver sensitivity to hazards decreased and tendency to make false alarms increased over time in the automated control condition, but not in the manual control condition. Drivers in both conditions detected fewer hazards as the drive progressed. Ratings of workload and task-induced stress were elevated similarly in both conditions. CONCLUSION: Partially automated driving appears to uniquely impair driver vigilance by reducing the ability to discriminate between benign and dangerous events in the driving environment as the drive progresses. APPLICATION: Applied interventions should target improvements in driver sensitivity to hazardous situations that signal potential automation failures.

Tactile Vigilance Is Stressful and Demanding.

OBJECTIVE: The primary aims of the study were to replicate the vigilance decrement in the tactile modality, examine whether a decrease in sensitivity is associated with the decrement, and determine whether tactile vigilance is stressful and demanding. BACKGROUND: When people monitor occasional and unpredictable signals for sustained durations, they experience a decline in performance known as the vigilance decrement, which has important practical consequences. Prior studies of the vigilance decrement focused primarily on visual vigilance and, to a lesser degree, on auditory vigilance. There are relatively few studies of tactile vigilance. METHOD: Participants monitored vibrotactile stimuli that were created from a tactor, for 40 min. RESULTS: Sensitivity declined, self-report ratings of distress increased, and ratings of task engagement decreased, during the vigil, and perceived workload was moderately high. CONCLUSION: Monitoring tactile signals is demanding and stressful and results in a decrement in signal detection. APPLICATION: Monitoring tactile signals may result in a decrement in tasks requiring discrimination, such as monitoring lane position with the use of rumble strips; these require discrimination between current road vibration and increased vibration when the car drifts out of its lane and crosses over the strip.

A Systematic Review and Meta-Analysis of Takeover Performance During Conditionally Automated Driving.

OBJECTIVE: The aim of this paper was to synthesize the experimental research on factors that affect takeover performance during conditionally automated driving. BACKGROUND: For conditionally automated driving, the automated driving system (ADS) can handle the entire dynamic driving task but only for limited domains. When the system reaches a limit, the driver is responsible for taking over vehicle control, which may be affected by how much time they are provided to take over, what they were doing prior to the takeover, or the type of information provided to them during the takeover. METHOD: Out of 8446 articles identified by a systematic literature search, 48 articles containing 51 experiments were included in the meta-analysis. Coded independent variables were time budget, non-driving related task engagement and resource demands, and information support during the takeover. Coded dependent variables were takeover timing and quality measures. RESULTS: Engaging in non-driving related tasks results in degraded takeover performance, particularly if it has overlapping resource demands with the driving task. Weak evidence suggests takeover performance is impaired with shorter time budgets. Current implementations of information support did not affect takeover performance. CONCLUSION: Future research and implementation should focus on providing the driver more time to take over while automation is active and should further explore information support. APPLICATION: The results of the current paper indicate the need for the development and deployment of vehicle-to-everything (V2X) services and driver monitoring.

Topical Review: Impact of Central Vision Loss on Navigation and Obstacle Avoidance while Walking.

SIGNIFICANCE: Individuals with central vision loss are at higher risk of injury when walking and thus may limit trips outside the home. Understanding the mobility challenges associated with central vision loss (CVL) can lead to more effective interventions.A systematic literature review focusing on mobility in CVL was conducted. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, 2424 articles were identified in 4 databases (PsycINFO, APA PsycArticles, PubMed, and Web of Science). To be included within this review, the study methodology needed to be related to the three components of walking: (1) navigation, defined as the ability to reach a target destination; (2) obstacle avoidance, defined as the ability to avoid collisions with obstacles located at various heights and directions; and (3) street crossing, defined as the ability to both navigate a path and avoid collisions in a traffic environment. The methodology also needed to be empirical. Case studies, unstructured observational studies, studies based on self-report, research proposals, and existing systematic reviews were excluded. Titles, abstracts, and full text of identified articles were screened, yielding 26 articles included in the review. Results showed that, in many tasks, individuals with CVL can accomplish a level of performance comparable with individuals with normal vision. Differences between normal and impaired vision were due to either age or how the groups completed the task. For example, individuals with CVL could cross a street successfully but did so less safely (i.e., smaller safety margins) than individuals with normal vision. To identify new interventions for CVL, future research should focus on the differences in the mechanisms underlying mobility between individuals with normal and impaired vision rather than solely on performance differences.

Object shape affects hand grip function for heavy objects in younger and older adults.

Hand-grip function while lifting objects is essential for performing everyday tasks. The Box and Block Test (BBT) has been used to assess hand-grip function and dexterity, but only light objects have been used. The purpose of this study was to investigate the effects of block surface, shape, age, and sex on hand dexterity during the movement of heavy blocks in the BBT. Forty healthy participants comprised of a younger group of 10 males (M = 22.50 years, SD = 2.01) and 10 females (M = 22.20 years, SD = 2.66) between 20 and 30-years-old, and an older group of 10 males (M = 55.80 years, SD = 3.19) and 10 females (M = 55.90 years, SD = 2.56) between 50 and 60-years-old, performed the BBT using steel objects of different shapes (cylindrical and cubic) and different surfaces (plain steel, black spray-painted steel, and yellow non-slip spray-painted steel). The results indicated that repetition and shape had significant effects on the BBT score. Previous researchers have found that surface textures, age, and sex influenced hand dexterity for light objects, but these effects were not discovered in the current study. These findings suggest that shape should take priority over age, sex, and surface texture when designing tools to improve user handling. Practitioner Summary: Hand-grip function is critically important when performing daily grip tasks such as picking up a writing utensil, using a toothbrush, or twisting a hand tool. The shape should be considered during the design process of tools and equipment used in industry so that handling can be made for the user. Abbreviations: BBT: box and block test; COF: coefficient of friction; BPS: blocks per second.

Evaluating Medical Devices Remotely: Current Methods and Potential Innovations.

OBJECTIVE: We present examples of laboratory and remote studies, with a focus on studies appropriate for medical device design and evaluation. From this review and description of extant options for remote testing, we provide methods and tools to achieve research goals remotely. BACKGROUND: The FDA mandates human factors evaluation of medical devices. Studies show similarities and differences in results collected in laboratories compared to data collected remotely in non-laboratory settings. Remote studies show promise, though many of these are behavioral studies related to cognitive or experimental psychology. Remote usability studies are rare but increasing, as technologies allow for synchronous and asynchronous data collection. METHOD: We reviewed methods of remote evaluation of medical devices, from testing labels and instruction to usability testing and simulated use. Each method was coded for the attributes (e.g., supported media) that need consideration in usability studies. RESULTS: We present examples of how published usability studies of medical devices could be moved to remote data collection. We also present novel systems for creating such tests, such as the use of 3D printed or virtual prototypes. Finally, we advise on targeted participant recruitment. CONCLUSION: Remote testing will bring opportunities and challenges to the field of medical device testing. Current methods are adequate for most purposes, excepting the validation of Class III devices. APPLICATION: The tools we provide enable the remote evaluation of medical devices. Evaluations have specific research goals, and our framework of attributes helps to select or combine tools for valid testing of medical devices.

Can Stroboscopic Training Improve Judgments of Time-to-Collision?

OBJECTIVE: The aim of this study was to determine whether training with stroboscopic viewing could improve time-to-collision (TTC) judgments, which have importance in real-world tasks such as driving. BACKGROUND: Prior research demonstrated that training with stroboscopic vision can improve motion coherence thresholds, improve anticipatory timing performance for laterally moving objects, and can protect against performance degradation over time. METHOD: Participants viewed computer simulations of an object that moved and then disappeared. In two separate experiments, the object approached the observer or moved laterally toward a target, representing different optical flow patterns. Participants judged TTC by pressing a button when they thought the object would hit them (approach), or the target (lateral). Performance was measured during four sessions-pretest, intervention, immediately after intervention, and 10 min after intervention. RESULTS: Both stroboscopic training and repeated practice improved performance over time for approach motion (decrease in constant error) and stroboscopic training protected against performance degradation for lateral motion (no decrement in variable error), but only when TTC was 3.0 s. There was no difference between training and repeated practice. CONCLUSION: Under certain conditions, stroboscopic training may improve TTC judgments. However, effects of stroboscopic training depend on the nature of the optical flow pattern. APPLICATION: It is important to determine the conditions under which training can improve TTC judgments which have importance in real-world tasks such as driving. If individuals can be trained to judge TTC more accurately, they may benefit from driver training programs.

Angle of Camera View Influences Resumption Lag in a Visual-Motor Task.

OBJECTIVE: To determine whether top-view and side-view camera angles, which putatively impose different cognitive demands, differentially affect the resumption lag in a visual-motor task relevant to laparoscopic surgery. BACKGROUND: Prior research showed that the time to resume a primary task after performing an interrupting task (resumption lag) increases with increases in the subjective workload of the primary task. Camera views used in laparoscopic surgery provide different views of the anatomy and have different cognitive costs and associated levels of workload. METHOD: Participants completed a peg transfer task while interrupted with a mental rotation task of different durations and angles of stimulus rotation. RESULTS: Participants required significantly more time to resume the peg transfer task when using a side view than a top view and when interrupted for a longer duration. Participants' ratings of subjective workload were consistent with these patterns of performance data; the side view resulted in longer resumption lags and was rated as greater in mental demand. Additionally, the time needed to resume the peg transfer task decreased across trials for both views. CONCLUSION: More time is required to resume an interrupted visual-motor task when it is more cognitively demanding than when it is less cognitively demanding possibly due to needing more time to learn the visual-motor mapping of the task higher in cognitive demand. APPLICATION: Training for laparoscopic surgery should include interruptions to allow surgeons to practice resuming a surgery-related task after an interruption and consequently shorten the time needed to resume the surgery-related task.

Driver Vigilance in Automated Vehicles: Effects of Demands on Hazard Detection Performance.

OBJECTIVE: The current study investigated driver vigilance in partially automated vehicles to determine whether increased task demands reduce a driver's ability to monitor for automation failures and whether the vigilance decrement associated with hazard detections is due to driver overload. BACKGROUND: Drivers of partially automated vehicles are expected to monitor for signs of automation failure. Previous research has shown that a driver's ability to perform this duty declines over time. One possible explanation for this vigilance decrement is that the extreme demands of vigilance causes overload and leads to depletion of limited attentional resources required for vigilance. METHOD: Participants completed a 40-min drive in a simulated partially automated vehicle and were tasked with monitoring for hazards that represented potential automation failures. Two factors were manipulated to test the impact of monitoring demands on performance: Spatial uncertainty and event rate. RESULTS: As predicted, hazard detection performance was poorer when monitoring demands were increased, and performance declined as a function of time on task. Subjective reports also indicated high workload and task-induced stress. CONCLUSION: Drivers of partially automated vehicles are impaired by the vigilance decrement and elevated task demands, meaning that safe operation becomes less likely when the demands associated with monitoring automation increase and as a drive extends in duration. This study also supports the notion that vigilance performance in partially automated vehicles is likely due to driver overload. APPLICATION: Developers of automation technologies should consider countermeasures that attenuate a driver's cognitive load when tasked with monitoring automation.

Evaluating a handheld decision support device in pediatric intensive care settings.

OBJECTIVE: To evaluate end-user acceptance and the effect of a commercial handheld decision support device in pediatric intensive care settings. The technology, pac2, was designed to assist nurses in calculating medication dose volumes and infusion rates at the bedside. MATERIALS AND METHODS: The devices, manufactured by InformMed Inc., were deployed in the pediatric and neonatal intensive care units in 2 health systems. This mixed methods study assessed end-user acceptance, as well as pac2's effect on the cognitive load associated with bedside dose calculations and the rate of administration errors. Towards this end, data were collected in both pre- and postimplementation phases, including through ethnographic observations, semistructured interviews, and surveys. RESULTS: Although participants desired a handheld decision support tool such as pac2, their use of pac2 was limited. The nature of the critical care environment, nurses' risk perceptions, and the usability of the technology emerged as major barriers to use. Data did not reveal significant differences in cognitive load or administration errors after pac2 was deployed. DISCUSSION AND CONCLUSION: Despite its potential for reducing adverse medication events, the commercial standalone device evaluated in the study was not used by the nursing participants and thus had very limited effect. Our results have implications for the development and deployment of similar mobile decision support technologies. For example, they suggest that integrating the technology into hospitals' existing IT infrastructure and employing targeted implementation strategies may facilitate nurse acceptance. Ultimately, the usability of the design will be essential to reaping any potential benefits.

Effects of Touch, Voice, and Multimodal Input, and Task Load on Multiple-UAV Monitoring Performance During Simulated Manned-Unmanned Teaming in a Military Helicopter.

OBJECTIVE: We evaluated three interface input methods for a simulated manned-unmanned teaming (MUM-T) supervisory control system designed for Air Mission Commanders (AMCs) in Black Hawk helicopters. BACKGROUND: A key component of the U.S. Army's vision for unmanned aerial vehicles (UAVs) is to integrate UAVs into manned missions, called MUM-T (Department of Defense, 2010). One application of MUM-T is to provide the AMC of a team of Black Hawk helicopters control of multiple UAVs, offering advanced reconnaissance and real-time intelligence of flight routes and landing zones. METHOD: Participants supervised a (simulated) team of two helicopters and three UAVs while traveling toward a landing zone to deploy ground troops. Participants classified aerial photographs collected by UAVs, monitored instrument warnings, and responded to radio communications. We manipulated interface input modality (touch, voice, multimodal) and task load (number of photographs). RESULTS: Compared with voice, touch and multimodal control resulted in better performance on all tasks and resulted in lower subjective workload and greater subjective situation awareness, ps < .05. Participants with higher spatial ability classified more aerial photographs ( r = .75) and exhibited shorter response times to instrument warnings ( r = -.58) than participants with lower spatial ability. CONCLUSION: Touchscreen and multimodal control were superior to voice control in a supervisory control task that involved monitoring visual displays and communicating on radio channels. APPLICATION: Although voice control is often considered a more natural and less physically demanding input method, caution is needed when designing visual displays for users sharing common communication channels.

Availability of attention affects time-to-contact estimation.

To estimate the time-to-contact (TTC) of a moving object, numerous studies have focused on the type of information or gaze strategy used by the observer. However, it remains to be determined whether and how attention could affect TTC estimation. In particular, how does TTC estimation operate when less attention is available? To answer this question, we conducted two experiments in which the participants had to perform an absolute (Experiment 1) or relative (Experiment 2) prediction-motion task, either alone (i.e., in single-task condition) or along with a secondary, visual working-memory task (i.e., in dual-task condition). In both experiments, we found that TTC estimation was superior in dual-task condition relative to single-task condition. This finding suggests that the reduction of available attention actually improves TTC estimation. We discuss possible explanations as well as theoretical implications for this seemingly counter-intuitive finding. Further research is needed to investigate if (in)attention facilitates or only shifts TTC estimation.

Driver Vigilance in Automated Vehicles: Hazard Detection Failures Are a Matter of Time.

OBJECTIVE: The primary aim of the current study was to determine whether monitoring the roadway for hazards during automated driving results in a vigilance decrement. BACKGROUND: Although automated vehicles are relatively novel, the nature of human-automation interaction within them has the classic hallmarks of a vigilance task. Drivers must maintain attention for prolonged periods of time to detect and respond to rare and unpredictable events, for example, roadway hazards that automation may be ill equipped to detect. Given the similarity with traditional vigilance tasks, we predicted that drivers of a simulated automated vehicle would demonstrate a vigilance decrement in hazard detection performance. METHOD: Participants "drove" a simulated automated vehicle for 40 minutes. During that time, their task was to monitor the roadway for roadway hazards. RESULTS: As predicted, hazard detection rate declined precipitously, and reaction times slowed as the drive progressed. Further, subjective ratings of workload and task-related stress indicated that sustained monitoring is demanding and distressing and it is a challenge to maintain task engagement. CONCLUSION: Monitoring the roadway for potential hazards during automated driving results in workload, stress, and performance decrements similar to those observed in traditional vigilance tasks. APPLICATION: To the degree that vigilance is required of automated vehicle drivers, performance errors and associated safety risks are likely to occur as a function of time on task. Vigilance should be a focal safety concern in the development of vehicle automation.