Karlene Ball

Age and visual search: expanding the useful field of view

The useful field of view is defined as the visual area in which information can be acquired within one eye fixation. We studied visual search within this context and found a reduction in the size of the field as a function of age. This loss, however, was recovered partially with practice. Standard acuity and perimetric tests of visual field, although diagnostic of disease, underestimate the degree of difficulty experienced by visually healthy older adults in everyday activities requiring the use of peripheral vision. To aid in predicting such performance, a model incorporating the effects of distractors and secondary task demands was developed.

VISUAL/COGNITIVE CORRELATES OF VEHICLE ACCIDENTS IN OLDER DRIVERS

Older drivers have more accidents per miles driven than any other age group and tend to have significant impairments in their visual function, which could interfere with driving. Previous research has largely failed to document a link between vision and driving in the elderly. We have taken a comprehensive approach by examining how accident frequency in older drivers relates to the visual/cognitive system at a number of levels: ophthalmological disease, visual function, visual attention, and cognitive function. The best predictor of accident frequency as recorded by the state was a model incorporating measures of early visual attention and mental status, which together accounted for 20% of the variance, a much stronger model than in earlier studies. Those older drivers with a visual attentional disorder or with poor scores on a mental status test had 3-4 times more accidents (of any type) and 15 times more intersection accidents than those without these problems.

DRIVING AVOIDANCE AND FUNCTIONAL IMPAIRMENT IN OLDER DRIVERS

The purpose of this study was to examine the association between visual and cognitive impairment in older drivers and their avoidance of potentially challenging, driving situation. A group of 257 older drivers participated in assessments of visual sensory function, eye health and cognitive function including the useful field of view test, and completed a structured questionnaire on driving exposure and how frequently they avoided challenging driving situations. Results replicated earlier studies showing that many older drivers limit their exposure to driving situations which are generally believed to be more difficult (e.g. rain, night, heavy traffic, rush hour). Furthermore, older drivers with objectively determined visual and/or attentional impairments reported more avoidance than those free of impairments; those with the most impairment reported avoiding more types of situations than other less impaired or non-impaired drivers. Older drivers with a history of at-fault crashes in the prior five years reported more avoidance than those who had crash-free records. Future research should evaluate the potentially beneficial role of self-regulation in enhancing older driver safety, particularly in those older drivers with visual and attentional processing impairments who have elevated crash risk.

Direction-specific improvement in motion discrimination

With training, an observers ability to discriminate similar directions of motion gradually improves. A series of studies reveals that this improvement, (1) is restricted to the trained direction and other, similar directions, (2) persists for at least several months, (4) shows appreciable, but not complete, transfer between the two eyes, and (5) is largely restricted to the stimulated region of the field. Moreover, the improvement in direction discrimination does not produce a concomitant change in detection thresholds. In all likelihood, most of the improvement in direction discrimination represents a change in visual function, rather than changes in nonsensory processes.

Can High-Risk Older Drivers Be Identified Through Performance-Based Measures in a Department of Motor Vehicles Setting?

OBJECTIVES: To evaluate the relationship between performance‐based risk factors and subsequent at‐fault motor vehicle collision (MVC) involvement in a cohort of older drivers.

Ten-Year Effects of the Advanced Cognitive Training for Independent and Vital Elderly Cognitive Training Trial on Cognition and Everyday Functioning in Older Adults

To determine the effects of cognitive training on cognitive abilities and everyday function over 10 years.

The Impact of Speed of Processing Training on Cognitive and Everyday Functions

We combined data from six studies, all using the same speed of processing training program, to examine the mechanisms of training gain and the impact of training on cognitive and everyday abilities of older adults. Results indicated that training produces immediate improvements across all subtests of the Useful Field of View test, particularly for older adults with initial speed of processing deficits. Age and education had little to no impact on training gain. Participants maintained benefits of training for at least 2 years, which translated to improvements in everyday abilities, including efficient performance of instrumental activities of daily living and safer driving performance.

Identifying Correlates of Accident Involvement for the Older Driver

Most older adults rely on the automobile to maintain their mobility and independence, in spite of the fact that age-related behavioral and biomedical changes may make driving more difficult. Indeed, accident and fatality rates begin to rise after age 55. One research goal, therefore, is to identify functional measures that differentiate older adults who drive safely from those who do not. This paper discusses conceptual and methodological issues involved in addressing this question, considers why earlier research has been largely unsuccessful, presents a working model for approaching the problem, and argues the need for large-sample, prospective research in this area

ACTIVE: a cognitive intervention trial to promote independence in older adults.

The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial is a randomized, controlled, single-masked trial designed to determine whether cognitive training interventions (memory, reasoning, and speed of information processing), which have previously been found to be successful at improving mental abilities under laboratory or small-scale field conditions, can affect cognitively based measures of daily functioning. Enrollment began during 1998; 2-year follow-up will be completed by January 2002. Primary outcomes focus on measures of cognitively demanding everyday functioning, including financial management, food preparation, medication use, and driving. Secondary outcomes include health-related quality of life, mobility, and health-service utilization. Trial participants (n = 2832) are aged 65 and over, and at entry into the trial, did not have significant cognitive, physical, or functional decline. Because of its size and the carefully developed rigor, ACTIVE may serve as a guide for future behavioral medicine trials of this nature.

Visual localization: age and practice

Older people seem to be highly susceptible to the distracting effects of irrelevant or interfering visual stimuli. We studied this susceptibility using visual displays in which observers had to localize the position of a face. When a face appeared in isolation, observers of all ages did equally well; when distracting stimuli surrounded the face, older observers alone performed poorly. Brief periods of practice produce substantial and long-lasting improvement in performance.