Could driving help us to "see better"? A comparative assessment of saccadic efficiency, visual speed, and attention.

BACKGROUND: This study aimed at comparing drivers' and non-drivers' results in the Adult Developmental Eye Movement with Distractors test (ADEMd) and the Useful Field of View test (UFOV). METHODS: One hundred and twenty Spaniards (mean age 50.90 ± 17.32 years) without eye disease voluntarily participated in this cross-sectional descriptive study. Participants in a single experimental session completed a questionnaire on sociodemographic, health, eyesight, and driving information. They also performed the ADEMd and UFOV tests randomly following standardized protocols. The ADEMd is a visual-verbal test that measures saccadic efficiency and visual attention. Brown-Forsythe (B-F) tests with Games-Howell post-hoc adjustments were conducted to assess differences between groups. Groups were formed according to sex, age (young adults, adults, and older adults), and driver/non-driver for further analysis. Additionally, associations between dependent variables were assessed through Spearman's correlations. RESULTS: Drivers obtained significantly better results in the ADEMd compared with non-drivers. Non-significant differences between drivers and non-drivers were encountered in the UFOV. Additionally, significant differences were observed between sexes and age groups. It is worth highlighting that non-driver's age significantly correlated with worse ADEMd performance (rho = .637 to .716). This correlation was non-significant in drivers. Similarly, reading hours significantly correlated with better ADEMd performance in non-drivers (rho = - .291 to - .363), but not in drivers. The only significant correlations between ADEMd and UFOV tests were found in drivers (rho = .307 to .410). CONCLUSION: Considering all the discussed results, it could be hypothesized that the driving task promotes abilities, such as oculomotor and cognitive function, which are relevant for the performance in the ADEMd. However, this hypothesis is based on correlational outcomes and further studies should causally assess this possible relation.

Functional Neural Correlates of a Useful Field of View (UFOV)-Based fMRI Task in Older Adults.

Declines in processing speed performance occur in aging and are a critical marker of functional independence in older adults. Studies suggest that Useful Field of View (UFOV) training may ameliorate cognitive decline. Despite its efficacy, little is known about the neural correlates of this task. Within the current study, 233 healthy older adults completed a UFOV-based task while undergoing functional magnetic resonance imaging (fMRI). During the "stimulus" portion of this task, participants must identify a target in the center of the screen and the location of a target in the periphery, among distractors. During the "probe" portion, participants must decide if the object in the center and the location of the target in the periphery were identical to the "stimulus" screen. Widespread bilateral whole-brain activation was observed when activation patterns of the "probe" contrast were subtracted from the "stimulus" contrast. Conversely, the subtraction of "stimulus" from "probe" was associated with discrete activation patterns consisting of 13 clusters. Additionally, when evaluating the variance associated with task accuracy, specific subregions were identified that may be critical for task performance. Our data elucidate the functional neural correlates of a UFOV-based task, a task used in both cognitive training paradigms and assessment of function.

Measuring the Useful Field of View During Simulated Driving With Gaze-Contingent Displays.

OBJECTIVE: We aimed to develop and test a new dynamic measure of transient changes to the useful field of view (UFOV), utilizing a gaze-contingent paradigm for use in realistic simulated environments. BACKGROUND: The UFOV, the area from which an observer can extract visual information during a single fixation, has been correlated with driving performance and crash risk. However, some existing measures of the UFOV cannot be used dynamically in realistic simulators, and other UFOV measures involve constant stimuli at fixed locations. We propose a gaze-contingent UFOV measure (the GC-UFOV) that solves the above problems. METHODS: Twenty-five participants completed four simulated drives while they concurrently performed an occasional gaze-contingent Gabor orientation discrimination task. Gabors appeared randomly at one of three retinal eccentricities (5°, 10°, or 15°). Cognitive workload was manipulated both with a concurrent auditory working memory task and with driving task difficulty (via presence/absence of lateral wind). RESULTS: Cognitive workload had a detrimental effect on Gabor discrimination accuracy at all three retinal eccentricities. Interestingly, this accuracy cost was equivalent across eccentricities, consistent with previous findings of "general interference" rather than "tunnel vision." CONCLUSION: The results showed that the GC-UFOV method was able to measure transient changes in UFOV due to cognitive load in a realistic simulated environment. APPLICATION: The GC-UFOV paradigm developed and tested in this study is a novel and effective tool for studying transient changes in the UFOV due to cognitive load in the context of complex real-world tasks such as simulated driving.

The impact of a tDCS and cognitive training intervention on task-based functional connectivity.

Declines in several cognitive domains, most notably processing speed, occur in non-pathological aging. Given the exponential growth of the older adult population, declines in cognition serve as a significant public health issue that must be addressed. Promising studies have shown that cognitive training in older adults, particularly using the useful field of view (UFOV) paradigm, can improve cognition with moderate to large effect sizes. Additionally, meta-analyses have found that transcranial direct current stimulation (tDCS), a non-invasive form of brain stimulation, can improve cognition in attention/processing speed and working memory. However, only a handful of studies have looked at concomitant tDCS and cognitive training, usually with short interventions and small sample sizes. The current study assessed the effect of a tDCS (active versus sham) and a 3-month cognitive training intervention on task-based functional connectivity during completion of the UFOV task in a large older adult sample (N = 153). We found significant increased functional connectivity between the left and right pars triangularis (the ROIs closest to the electrodes) following active, but not sham tDCS. Additionally, we see trending behavioral improvements associated with these functional connectivity changes in the active tDCS group, but not sham. Collectively, these findings suggest that tDCS and cognitive training can be an effective modulator of task-based functional connectivity above and beyond a cognitive training intervention alone.

Task-based functional connectivity of the Useful Field of View (UFOV) fMRI task.

Declines in processing speed performance occur in aging and are a critical marker of functional independence in older adults. Numerous studies suggest that Useful Field of View (UFOV) training may ameliorate cognitive decline in older adults. Despite its efficacy, little is known about the neural correlates of this task. The current study is the first to investigate the coherence of functional connectivity during UFOV task completion. A total of 336 participants completed the UFOV task while undergoing task-based functional magnetic resonance imaging (fMRI). Ten spherical regions of interest (ROIs), selected a priori, were created based on regions with the greatest peak BOLD activation patterns in the UFOV fMRI task and regions that have been shown to significantly relate to UFOV fMRI task performance. We used a weighted ROI-to-ROI connectivity analysis to model task-specific functional connectivity strength between these a priori selected ROIs. We found that our UFOV fMRI network was functionally connected during task performance and was significantly associated to UFOV fMRI task performance. Within-network connectivity of the UFOV fMRI network showed comparable or better predictive power in accounting for UFOV accuracy compared to 7 resting state networks, delineated by Yeo and colleagues. Finally, we demonstrate that the within-network connectivity of UFOV fMRI task accounted for scores on a measure of "near transfer", the Double Decision task, better than the aforementioned resting state networks. Our data elucidate functional connectivity patterns of the UFOV fMRI task. This may assist in future targeted interventions that aim to improve synchronicity within the UFOV fMRI network.

Structural Neural Correlates of Double Decision Performance in Older Adults.

Speed of processing is a cognitive domain that encompasses the speed at which an individual can perceive a given stimulus, interpret the information, and produce a correct response. Speed of processing has been shown to decline more rapidly than other cognitive domains in an aging population, suggesting that this domain is particularly vulnerable to cognitive aging (Chee et al., 2009). However, given the heterogeneity of neuropsychological measures used to assess the domains underpinning speed of processing, a diffuse pattern of brain regions has been implicated. The current study aims to investigate the structural neural correlates of speed of processing by assessing cortical volume and speed of processing scores on the POSIT Double Decision task within a healthy older adult population (N = 186; mean age = 71.70 ± 5.32 years). T1-weighted structural images were collected via a 3T Siemens scanner. The current study shows that less cortical thickness in right temporal, posterior frontal, parietal and occipital lobe structures were significantly associated with poorer Double Decision scores. Notably, these include the lateral orbitofrontal gyrus, precentral gyrus, superior, transverse, and inferior temporal gyrus, temporal pole, insula, parahippocampal gyrus, fusiform gyrus, lingual gyrus, superior and inferior parietal gyrus and lateral occipital gyrus. Such findings suggest that speed of processing performance is associated with a wide array of cortical regions that provide unique contributions to performance on the Double Decision task.

More than the Useful Field: Considering peripheral vision in driving.

Applied research on driving and basic vision research have held similar views on central, fovea-based vision as the core of visual perception. In applied work, the concept of the Useful Field, as determined by the Useful Field of View (UFOV) test, divides vision between a "useful" region towards the center of the visual field, and the rest of the visual field. While compelling, this dichotomization is at odds with findings in vision science which demonstrate the capabilities of peripheral vision. In this paper, we examine driving research from this new perspective, and argue for the need for an updated understanding of how drivers acquire information about their operating environment using peripheral vision. The concept of the Useful Field and the UFOV test are not discarded; instead we discuss their strengths, limitations, and future directions. We discuss key findings from vision science on peripheral vision, and a theory that provides insights into its capabilities and limitations. This more complete basic science understanding of peripheral vision informs appropriate use of the UFOV and the Useful Field in driving research going forward.

Examining links between cognitive markers, movement initiation and change, and pedestrian safety in older adults.

OBJECTIVE: The purpose of this study was to determine the extent to which mobility indices (such as walking speed and postural sway), motor initiation, and cognitive function, specifically executive functions, including spatial planning, visual attention, and within participant variability, differentially predicted collisions in the near and far sides of the road with increasing age. METHODS: Adults aged over 45 years participated in cognitive tests measuring executive function and visual attention (using Useful Field of View; UFoV(®)), mobility assessments (walking speed, sit-to-stand, self-reported mobility, and postural sway assessed using motion capture cameras), and gave road crossing choices in a two-way filmed real traffic pedestrian simulation. RESULTS: A stepwise regression model of walking speed, start-up delay variability, and processing speed) explained 49.4% of the variance in near-side crossing errors. Walking speed, start-up delay measures (average and variability), and spatial planning explained 54.8% of the variance in far-side unsafe crossing errors. Start-up delay was predicted by walking speed only (explained 30.5%). CONCLUSION: Walking speed and start-up delay measures were consistent predictors of unsafe crossing behaviours. Cognitive measures, however, differentially predicted near-side errors (processing speed), and far-side errors (spatial planning). These findings offer potential contributions for identifying and rehabilitating at-risk older pedestrians.

The Transfer of Cognitive Speed of Processing Training to Older Adults' Driving Mobility Across 5 Years.

OBJECTIVES: Multilevel models assessed the effects of cognitive speed of processing training (SPT) on older adults' self-reported driving using intention-to-treat (ITT, randomization to training or control conditions) and dosage (treatment-received via number of training sessions) analyses across 5 years. METHOD: Participants randomized to SPT (n = 598) were compared with those randomized to either the no-contact control (n = 598) or memory training, which served as an active control (n = 610). Driving mobility (frequency, exposure, and space) was assessed over time. RESULTS: No significant effects were found within the ITT analyses. However, number of SPT sessions did affect driving mobility outcomes. In the full sample (N = 1,806), higher SPT doses were associated with maintained driving frequency as compared with both control groups, but no effects were found for driving exposure or space. Subsample analyses (n = 315) revealed that persons at-risk for mobility declines (i.e., poor initial processing speed) who received additional booster SPT sessions reported greater maintenance of both driving frequency and exposure over time as compared with the no-contact and active control groups. DISCUSSION: These results and prior research indicate that cognitive SPT transfers to prolonged driving mobility among older adults. Future research should investigate the mechanisms behind transfer effects to real-world activities, such as driving.

[Principle of the useful field of view and normative data]. / Principes de réalisation du champ visuel attentionnel et élaboration de normes.

PURPOSE: The useful field of view is a test which takes into account the influence of patient attention during the evaluation of the visual field. This study aims to generate normative data for an adaptation of the useful field of view (UFOV) test. These normative data are essential to judge, in a clinical setting, whether patients' performance is normal or not across demographically similar peers, in order to advise whether or not to resume driving after a brain injury (traumatic brain injury, stroke or cerebral tumour). PATIENTS AND METHODS: This study examined demographic influences on an UFOV adaptation in a sample of 52 control participants (17 males and 35 females, aged 19 to 69) with no prior ophthalmologic or neurologic history. This adaptation used three visual attention tasks. In a simple task (ST), the participant had to detect, as fast as (s)he could, a single target in a visual display; in a double task (DT,) (s)he had to detect both a central and a lateral target in a double task with visual distractions present on the screen. The number of missed targets and the time needed to detect them are measured. RESULTS: Time to detect target was found to differ by gender and by age. Men and young people (from 19 to 29 years) are faster at detecting central and lateral targets. However, no demographic influence was observed on the number of missed targets. CONCLUSIONS: A normative table for this French UFOV adaptation is provided. This will allow clinicians to compare patient performance with similar peers and may help in identifying persons who would benefit from training on a driving simulator or having a road test with a driving-school.

The effects of age and workload on 3D spatial attention in dual-task driving.

In the present study we assessed whether the limits in visual-spatial attention associated with aging affect the spatial extent of attention in depth during driving performance. Drivers in the present study performed a car-following and light-detection task. To assess the extent of visual-spatial attention, we compared reaction times and accuracy to light change targets that varied in horizontal position and depth location. In addition, because workload has been identified as a factor that can change the horizontal and vertical extent of attention, we tested whether variability of the lead car speed influenced the extent of spatial attention for younger or older drivers. For younger drivers, reaction time (RT) to light-change targets varied as a function of distance and horizontal position. For older drivers RT varied only as a function of distance. There was a distance by horizontal position interaction for younger drivers but not for older drivers. Specifically, there was no effect of horizontal position at any given level of depth for older drivers. However, for younger drivers there was an effect of horizontal position for targets further in depth but not for targets nearer in depth. With regards to workload, we found no statistically reliable evidence that variability of the lead car speed had an effect on the spatial extent of attention for younger or older drivers. In a control experiment, we examined the effects of depth on light detection when the projected size and position of the targets was constant. Consistent with our previous results, we found that drivers' reaction time to light-change targets varied as a function of distance even when 2D position and size were controlled. Given that depth is an important dimension in driving performance, an important issue for assessing driving safety is to consider the limits of attention in the depth dimension. Therefore, we suggest that future research should consider the importance of depth as a dimension of spatial attention in relation to the assessment of driving performance.

Augmented reality cues to assist older drivers with gap estimation for left-turns.

The objective of this study was to assess the effects of augmented reality (AR) cues designed to assist middle-aged and older drivers with a range of UFOV impairments, judging when to make left-turns across oncoming traffic. Previous studies have shown that AR cues can help middle-aged and older drivers respond to potential roadside hazards by increasing hazard detection without interfering with other driving tasks. Intersections pose a critical challenge for cognitively impaired drivers, prone to misjudge time-to-contact with oncoming traffic. We investigated whether AR cues improve or interfere with hazard perception in left-turns across oncoming traffic for drivers with age-related cognitive decline. Sixty-four middle-aged and older drivers with a range of UFOV impairment judged when it would be safe to turn left across oncoming traffic approaching the driver from the opposite direction in a rural stop-sign controlled intersection scenario implemented in a static base driving simulator. Outcome measures used to evaluate the effectiveness of AR cueing included: Time-to-Contact (TTC), Gap Time Variation (GTV), Response Rate, and Gap Response Variation (GRV). All drivers estimated TTCs were shorter in cued than in uncued conditions. In addition, drivers responded more often in cued conditions than in uncued conditions and GRV decreased for all drivers in scenarios that contained AR cues. For both TTC and response rate, drivers also appeared to adjust their behavior to be consistent with the cues, especially drivers with the poorest UFOV scores (matching their behavior to be close to middle-aged drivers). Driver ratings indicated that cueing was not considered to be distracting. Further, various conditions of reliability (e.g., 15% miss rate) did not appear to affect performance or driver ratings.

Processing speed training increases the efficiency of attentional resource allocation in young adults.

Cognitive training has been shown to improve performance on a range of tasks. However, the mechanisms underlying these improvements are still unclear. Given the wide range of transfer effects, it is likely that these effects are due to a factor common to a wide range of tasks. One such factor is a participant's efficiency in allocating limited cognitive resources. The impact of a cognitive training program, Processing Speed Training (PST), on the allocation of resources to a set of visual tasks was measured using pupillometry in 10 young adults as compared to a control group of a 10 young adults (n = 20). PST is a well-studied computerized training program that involves identifying simultaneously presented central and peripheral stimuli. As training progresses, the task becomes increasingly more difficult, by including peripheral distracting stimuli and decreasing the duration of stimulus presentation. Analysis of baseline data confirmed that pupil diameter reflected cognitive effort. After training, participants randomized to PST used fewer attentional resources to perform complex visual tasks as compared to the control group. These pupil diameter data indicated that PST appears to increase the efficiency of attentional resource allocation. Increases in cognitive efficiency have been hypothesized to underlie improvements following experience with action video games, and improved cognitive efficiency has been hypothesized to underlie the benefits of PST in older adults. These data reveal that these training schemes may share a common underlying mechanism of increasing cognitive efficiency in younger adults.

Race-related disparities in 5-year cognitive level and change in untrained ACTIVE participants.

OBJECTIVE: The current study examined a 5-year cognitive change in untrained African American and White participants from the Advanced Cognitive Training in Independent and Vital Elderly (ACTIVE) study. METHOD: Five-year trajectories of memory, reasoning, visual processing speed/useful field of view, digit-symbol substitution, and vocabulary were investigated. Education, health, gender, age, and retest/practice effects were controlled for, and a missing data pattern mixture approach was used to adjust for dropout effects. RESULTS: After considering age, education, health, and gender, being African American uniquely explained 2% to 7% of the variance in cognitive performance. There were virtually no significant race differences in the rates of change. DISCUSSION: Race-related results in the current study are consistent with previous research suggesting that social advantage factors such as education have a stronger influence on the level of performance than the rate of change. The small remaining effects of being African American on performance levels likely reflect uncontrolled variation in factors like literacy and financial advantage.

Speed of processing training in the ACTIVE study: how much is needed and who benefits?

OBJECTIVES: Cognitive training has been shown to improve both cognitive and everyday abilities in older adults; however, little is known concerning the amount of training needed or the characteristics of those who benefit. These analyses examined the longitudinal impact of dosage (number of training sessions) on the improvement and maintenance of cognitive and everyday function. METHODS: ACTIVE is a longitudinal, randomized, single-blind clinical trial evaluating cognitive interventions in older adults (aged 65-94) from six states in the United States. RESULTS: Latent growth curve models indicated that initial training effects were maintained over 5 years and amplified by booster sessions. A single booster session counteracted 4.92 months of age-related processing speed decline. DISCUSSION: Cognitive performance improved by 2.5 standard deviations for participants who attended all 10 initial sessions and all 8 booster sessions compared to randomized participants who attended none. Implications for the broader application of cognitive training interventions are discussed.