Sex differences in patterns of cognitive test performance have been attributed to factors, such as sex hormones or sexual dimorphisms in brain structure, that change with normal aging. The current ...study examined sex differences in patterns of cognitive test performance in healthy elderly individuals. Cognitive test scores of 957 men and women (age 67-89), matched for overall level of cognitive test performance, age, education, and depression scale score, were compared. Men and women were indistinguishable on tests of auditory divided attention, category fluency, and executive functioning. In contrast, women performed better than men on tests of psychomotor speed and verbal learning and memory, whereas men outperformed women on tests of visuoconstruction and visual perception. Our finding that the pattern of sex differences in cognition observed in young adults is observed in old age has implications for future studies of both healthy elderly individuals and of those with cognitive disorders.
Older drivers may place restrictions on their driving by reducing their mileage and avoiding high-risk driving situations in an effort to improve safety. This project identifies what types of visual ...function loss are associated with subsequent driving modifications.
Data were used from the baseline and 2-year follow-up rounds of the Salisbury Eye Evaluation project, a cohort study of 2520 older adults. Measures of visual function tested were visual acuity, contrast sensitivity, visual fields, and glare sensitivity. Driving information was self-reported. Among drivers at baseline who continued to drive at follow-up, multiple logistic regression was used to estimate the odds of incident driving modification by visual function status.
Worse baseline scores in acuity, contrast sensitivity, and central and lower peripheral visual fields were individually associated with an increased odds of reduced mileage 2 years later (linear trend P < 0.05). Worse baseline scores in contrast sensitivity and central and lower peripheral visual fields were individually associated with a greater odds of cessation of night driving 2 years later, whereas worse baseline acuity scores were associated with an increased odds of cessation of driving in an unfamiliar areas 2 years later (linear trend P < 0.05).
Older drivers with worse visual function were more likely to modify their driving by reducing mileage and avoiding high-risk driving situations. Furthermore, these modifications to driving differed depending on what type of visual function was affected.
To determine the association between visual field loss and orientation and mobility (O&M) performance in a population-based sample of older adults and to identify the specific regions of the visual ...field that are most strongly associated with O&M performance.
A population-based sample of 1504 persons between the ages of 72 to 92 was enrolled in the third round of Salisbury Eye Evaluation. Monocular visual fields (60 degrees radius) were tested with the 81-point, single intensity (24 dB) screening test strategy on the Humphrey Field Analyzer. Binocular visual fields were estimated from a combination of the monocular fields. The number of points missed was calculated for the overall visual field and for 3 non-overlapping regions: central (< or = 20 degrees radius), upper- and lower-peripheral visual fields. Orientation and mobility performance was evaluated by walking speed, number of bumps, and number of orientation errors on a circuitous, 32.8-m course seeded with obstacles. Log-linear regressions and linear regressions, adjusting for age, gender, body mass, height, cognitive and general health status, were performed.
Loss in the overall visual field was associated with an increase in the number of bumps and decrease in walking speed. Visual field loss was not associated with the number of orientation errors. Out of the three visual field sub-regions that we tested, in terms of percentage of loss, the central and lower peripheral regions showed comparable decrements in walking speed and the central region was most strongly associated with number of bumps.
The loss in visual field, which occurs with aging, is associated with a decline in mobility performance. Walking speed decreases, and the number of bumps into obstacles increases, with decreases in the visual field. The number of orientation errors is not associated with the loss in visual field that occurs with aging.
Our purpose was to determine visual and cognitive predictors for older drivers’ failure to stop at stop signs. 1425 drivers aged between ages 67 and 87 residing in Salisbury Maryland were enrolled in ...a longitudinal study of driving. At baseline, the participants were administered a battery of vision and cognition tests, and demographic and health questionnaires. Five days of driving data were collected with a Driving Monitoring System (DMS), which obtained data on stop signs encountered and failure to stop at stop signs. Driving data were also collected 1 year later (round two). The outcome, number of times a participant failed to stop at a stop sign at round two, was modeled using vision and cognitive variables as predictors. A negative binomial regression model was used to model the failure rate. Of the 1241 who returned for round two, 1167 drivers had adequate driving data for analyses and 52 did not encounter a stop sign. In the remaining 1115, 15.8% failed at least once to stop at stop signs, and 7.1% failed to stop more than once. Rural drivers had 1.7 times the likelihood of not stopping compared to urban drivers. Amongst the urban participants, the number of points missing in the bilateral visual field was significantly associated with a lower failure rate. In this cohort, older drivers residing in rural areas were less likely to stop at stop-sign intersections than those in urban areas. It is possible that rural drivers frequent areas with less traffic and better visibility, and may be more likely to take the calculated risk of not stopping. In this cohort failure to stop at stop signs was not explained by poor vision or cognition. Conversely in urban areas, those who have visual field loss appear to be more cautious at stop signs.
Critical points were computed to determine the minimum field of view (FOV) size required for efficient navigation. Navigation performance in 20 normally sighted subjects was assessed using an ...immersive virtual environment. Subjects were instructed to walk through a virtual forest to a target tree as quickly as possible without hitting any obstacles (trees, boulders, and holes). The navigation task was performed in three FOV and image contrast conditions under binocular, monocular, chromatic and achromatic viewing conditions. FOV was constricted to 10°, 20° and 40° diameter and average image contrast was nominally high (11%), medium (6%) and low (3%). Navigation performance was scored as latency in walk initiation, walk time to reach goal and the number of obstacle contacts. The results revealed a linear relationship between log FOV and the two time measures, log latency and log walk time. The slopes of the linear regressions for log latency and log walk time ranged between –0.11 and –0.41. Critical points were computed from the non-linear relationships found between the number of obstacle contacts and FOV. The critical points for efficient navigation were FOVs of 32.1°, 18.4° and 10.9° (diam.) for low, medium and high image contrast levels, respectively, highlighting the importance of contrast on the size of the FOV required for efficient navigation. Neither binocularity nor image chromaticity significantly affected navigation performance. The findings of this study have important implications in the design and prescription of head mounted displays intended to augment navigation performance.
The impact of a central or peripheral visual field loss on the vision strategy used to guide walking was determined by measuring walking paths of visually impaired participants. An immersive virtual ...environment was used to dissociate the expected paths of the optic-flow and egocentric-direction strategies by offsetting the walker’s point of view from the actual direction of walking. Environments consisted of a goal within a forest, the goal alone, or the forest alone following a brief presentation of the goal. The first two environments allowed an evaluation of the visual information used in a goal-directed task whereas the third environment investigated the information used in a memory-guided task. Participants had either a central (CFL) or peripheral visual field loss (PFL) or were fully sighted (FS). Results showed that, for the goal-directed task, the CFL group was less influenced by optic flow than was an age-matched FS group. Optic flow decreased heading error by only 1.3° (16%) in the CFL group compared to 3.6° (42%) in the FS group. The PFL group showed an optic-flow influence (2.4° or 26%) comparable to an older, age-matched FS group (2.9° or 31%). For the memory-guided task, all but the PFL group had heading errors comparable to those obtained in the goal-alone scene, demonstrating the ability to use an egocentric-direction strategy with a stored representation of either the goal’s position or an offset relative to a landmark instead of a visible goal. The paths of the PFL group veered significantly from the predicted paths of both the optic-flow and egocentric-direction strategies. The findings of this study suggest that central vision is important for using optic flow to guide walking, whereas peripheral vision is important for establishing and/or updating an accurate representation of spatial structure for navigation.
To determine the visual and other factors that predict stopping or restricting driving in older drivers.
A group of 1425 licensed drivers aged 67 to 87 years, who were residents of greater Salisbury, ...participated. At 1 year after enrollment, this group was categorized into those who had stopped driving, drove only within their neighborhood, or continued to drive beyond their neighborhood. At baseline, a battery of structured questionnaires, vision, and cognitive tests were administered. Multivariate analysis determined the factors predictive of stopping or restricting driving 12 months later.
Of the 1425 enrolled, 1237 (87%) were followed up at 1 year. Excluding those who were already limiting their driving at baseline (n = 35), 1.5% (18/1202) had stopped and 3.4% (41/1202) had restricted their driving. The women (odds ratio OR, 4.01; 95% confidence interval CI, 2.05-8.20) and those who prefer to be driven (OR, 3.91; 95% CI, 1.91-8.00) were more likely to stop or restrict driving. Depressive symptoms increased likelihood of restricting or stopping driving (OR, 1.08; 95% CI, 1.009-1.16 per point Geriatric Depression Scale). Slow visual scanning and psychomotor speed (Trail Making Test, Part A: OR, 1.02; 95% CI, 1.01-1.03), poor visuoconstructional skills (Beery-Buktenica Test of Visual Motor Integration: OR, 1.14; 95% CI, 1.05-1.25), and reduced contrast sensitivity (OR, 1.15; 95% CI, 1.03-1.28) predicted stopping or reducing driving. Visual field loss and visual attention were not associated. The effect of vision on changing driving behavior was partially mediated by cognition, depression, and baseline driving preferences.
In this cohort, contrast sensitivity and cognitive function were independently associated with incident cessation or restriction of driving space. These data suggest drivers with functional deficits make difficult decisions to restrict or stop driving.
Four participants viewed artwork (5 abstract and 9 representational paintings) displayed in a museum, while wearing a portable eye tracker. We tested whether features in the paintings would determine ...the viewers' saccade-fixation patterns and viewing times. Participants produced unique eye-movement patterns that varied with each painting, regardless of genre. Some fixations clustered on features, predefined as informative of a narrative illustrated by the painting, whereas other fixations fell on homogenous patches of color; however, the features selected for fixation varied considerably across viewers and paintings. Participants' mean fixation durations for abstract artwork increased as viewing time progressed, suggesting that eye movement patterns change over time. Participants' aesthetic judgments of the paintings were not significantly correlated with fixation durations or viewing time, contrary to our predictions. Results are discussed in terms of cognitive factors that may influence eye movements made when viewing artwork in a real-world setting.
► Rapid deceleration events were examined over a 5-day period of monitoring in a cohort of drivers aged 67–87years. ► Approximately 30% of drivers had events and a third of these had four or more ...events. ► Older drivers with rapid deceleration events had slightly better performance on measures of vision and cognition.
Drivers who rapidly change speed while driving may be more at risk for a crash. We sought to determine the relationship of demographic, vision, and cognitive variables with episodes of rapid decelerations during five days of normal driving in a cohort of older drivers. In the Salisbury Eye Evaluation Driving Study, 1425 older drivers aged 67–87 were recruited from the Maryland Motor Vehicle Administration's rolls for licensees in Salisbury, Maryland. Participants had several measures of vision tested: visual acuity, contrast sensitivity, visual fields, and the attentional visual field. Participants were also tested for various domains of cognitive function including executive function, attention, psychomotor speed, and visual search. A custom created driving monitoring system (DMS) was used to capture rapid deceleration events (RDEs), defined as at least 350milli-g deceleration, during a five day period of monitoring. The rate of RDE per mile driven was modeled using a negative binomial regression model with an offset of the logarithm of the number of miles driven. We found that 30% of older drivers had one or more RDE during a five day period, and of those, about 1/3 had four or more. The rate of RDE per mile driven was highest for those drivers driving <59 miles during the 5-day period of monitoring. However, older drivers with RDE's were more likely to have better scores in cognitive tests of psychomotor speed and visual search, and have faster brake reaction time. Further, greater average speed and maximum speed per driving segment was protective against RDE events. In conclusion, contrary to our hypothesis, older drivers who perform rapid decelerations tend to be more “fit”, with better measures of vision and cognition compared to those who do not have events of rapid deceleration.
Laboratory-based models of oculomotor strategy that differ in the amount and type of top-down information were evaluated against a baseline case of random scanning for predicting the gaze patterns of ...subjects performing a real-world activity––walking to a target. Images of four subjects’ eyes and field of view were simultaneously recorded as they performed the mobility task. Offline analyses generated movies of the eye on scene and a categorization scheme was used to classify the locations of the fixations. Frames from each subject’s eye-on-scene movie served as input to the models, and the location of each model’s predicted fixations was classified using the same categorization scheme.
The results showed that models with no top-down information (visual salience model) or with only coarse feature information performed no better than a random scanner; the models’ ordered fixation locations (gaze pattern) matched less than a quarter of the subjects’ gaze patterns. A model that used only geographic information outperformed the random scanner and matched approximately a third of the gaze patterns. The best performance was obtained from an oculomotor strategy that used both coarse feature and geographic information, matching nearly half the gaze patterns (48%). Thus, a model that uses top-down information about a target’s coarse features and general vicinity does a fairly good job predicting fixation behavior, but it does not fully specify the gaze pattern of a subject walking to a target. Additional information is required, perhaps in the form of finer feature information or knowledge of a task’s procedure.
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