This annex includes entries for nearly all of the references consulted in the preparation of this report. It provides bibliographic information, keywords to allow selection of references related to specific concepts, and abstracts for all references included. In addition, notes have been added by the study team in some cases. The notes were developed for use by the study team in reviewing and evaluating the literature. They address major findings, methodology issues, relevance of particular studies to issues addressed in this research effort, and relationships among references. The only references for which no entries are provided here are a few entire books or long book chapters that were cited in the report, but were impractical to abstract.
In the great majority of cases, abstracts were provided by the authors of the references cited. Where no author's abstract was available, we have noted the source of the abstract or summary provided here. Some are authors' introductions, conclusions, or summaries; others were written by the study team.
Authors' note: Additional references obtained after the initial submission of this report have been added to this bibliography.
Author: Andre, J. T.
Date: 1995.
Title: Visual functioning in challenging conditions: Measuring and predicting the effects of alcohol consumption, stimulus motion, luminance and glare on contrast sensitivity.
Pub: Dissertation abstract.
Keywords:
Contrast sensitivity
Driving
Impairment
Low contrast acuity
Luminance
Motion detection
Spatial frequency
Holding: Full text ( ) Abstract/Summary (X) Reference only ( ) Other ( )
Abstract:
In an effort to assess the capabilities and limitations of human spatial vision, the present study investigated the individual and combined effects of the visual stressors of low luminance, alcohol consumption, stimulus motion and glare on contrast sensitivity for sine-wave gratings of different spatial frequencies. A secondary purpose was to explore the relationships among indices of intoxication, dark focus of accommodation and contrast sensitivity performance. Twelve naive subjects participated in two experimental sessions: Placebo (subjects expected alcohol but received only a negligible amount) and Alcohol (subjects expected and received 95% grain alcohol; mean breath alcohol content [BAC] = 0.073%). Contrast sensitivity was determined for 1.5, 3 and 6 cycles per degree gratings that were either stationary or traveled through a circular path, requiring pursuit eye movements.
Luminance was manipulated using a neutral density filter and the glare source consisted of six halogen bulbs that surrounded the stimulus. It was hypothesized that contrast sensitivity would be lowest in the condition with the greatest number of stressors, but it was not known if the stressors' effects would be interactive. Lowering luminance decreased contrast sensitivity by .27 log unit; adding the glare source further reduced contrast sensitivity by .28 log unit. Alcohol consumption and stimulus motion decreased contrast sensitivity by .16 and .10 log unit, respectively. All variables had interactive effects and decrements increased as spatial frequency increased.
The combined stressors effect was to decrease contrast sensitivity by 0.79 log unit, corresponding to 6.2 times more contrast necessary to reach threshold. Thus, the reduction or elimination of these effects should be of high priority in situations where optimal contrast sensitivity performance is desired. No useful relationships (for the drinker) were found between objective and subjective indices of intoxication. Further, subjective indices were not correlated positively with the alcohol-related loss in contrast sensitivity, although BAC was (r+.71). Subjective indices should not be used to predict BAC or alcohol related loss in contrast sensitivity. Dark focus values were unrelated to visual performance.
Authors: Andre, J. T., Tyrrell, R. A., Leibowitz, H. W., Nicholson, M. E., & Wang, M.
Date: 1994.
Title: Measuring and predicting the effects of alcohol consumption on contrast sensitivity for stationary and moving gratings.
Pub: Perception & Psychophysics, 56 (3), 261-267.
Keywords:
Acuity
Contrast sensitivity
Driving
Dynamic acuity
Impairments
Low contrast acuity
Motion detection
Spatial frequency
Static acuity
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
Contrast sensitivity was measured for 12 healthy young males while sober, after ingestion of an alcohol placebo, and after ingestion of alcohol (95% grain alcohol; mean estimated blood alcohol level = .088%). Observations were made for both stationary gratings and gratings that traveled through a circular path and required pursuit eye movements. The significant alcohol-related reduction in contrast sensitivity was 2.6 times greater for moving (.29-log-unit reduction) than for stationary gratings (.11-log-unit reduction). The loss in contrast sensitivity for the moving gratings of high spatial frequency (12 cpd) was particularly severe (.37 log unit). Estimated blood alcohol level was correlated with the loss in contrast sensitivity for moving gratings (r=.61), but not with the loss for stationary gratings. Estimated blood alcohol level was strongly correlated with the difference between the loss in contrast sensitivity to moving and stationary gratings (r=.75). These results are consistent with reports that alcohol consumption degrades the ability to make pursuit eye movements. Subjects' perceived intoxication level was not a reliable predictor of any index of visual performance.
Authors: Andre, J. T., Tyrrell, R. A., Leibowitz, H. W., Nicholson, M. E., & Wang, M.
Date: 1994.
Title: Measuring and predicting the effects of alcohol consumption on contrast sensitivity for stationary and moving gratings.
Pub: Perception & Psychophysics, 56 (3), 261-267.
Keywords:
Acuity
Contrast sensitivity
Driving
Dynamic acuity
Impairments
Low contrast acuity
Motion detection
Spatial frequency
Static acuity
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
Contrast sensitivity was measured for 12 healthy young males while sober, after ingestion of an alcohol placebo, and after ingestion of alcohol (95% grain alcohol; mean estimated blood alcohol level = .088%). Observations were made for both stationary gratings and gratings that traveled through a circular path and required pursuit eye movements. The significant alcohol-related reduction in contrast sensitivity was 2.6 times greater for moving (.29-log-unit reduction) than for stationary gratings (.11-log-unit reduction). The loss in contrast sensitivity for the moving gratings of high spatial frequency (12 cpd) was particularly severe (.37 log unit). Estimated blood alcohol level was correlated with the loss in contrast sensitivity for moving gratings (r=.61), but not with the loss for stationary gratings. Estimated blood alcohol level was strongly correlated with the difference between the loss in contrast sensitivity to moving and stationary gratings (r=.75). These results are consistent with reports that alcohol consumption degrades the ability to make pursuit eye movements. Subjects' perceived intoxication level was not a reliable predictor of any index of visual performance.
Authors: Bailey, L., & Sheedy, J.
Date: 1988.
Title: Visual screening for driver licensure.
Pub: Transportation in an aging society(Transportation Research Board special report, 218 (2)), 294-378.
Keywords:
Acuity
Aging
Driving
Dynamic acuity
Glare
Night vision
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract/Notes:
No author's abstract or summary given. Fairly extensive review of history and issues in vision screening for driver licensure. Addresses issues of testing and setting of standards, and policies for possible restriction of driving privileges, rather than only pass/fail testing. Suggests screening and standards for acuity (using current methods) and visual field (using white object on dark background), and research on dynamic acuity testing and glare susceptibility and night driving issues (including contrast sensitivity). States that "for these three aspects of vision [dynamic visual acuity, contrast sensitivity, glare sensitivity], there is presently insufficient information to justify any particular standard for license denial." (p.316)
Author: Baker, K.
Date: 1949.
Title: Some variables influencing vernier acuity.
Pub: Journal of the Optical Society of America, 39, 567-576.
Keywords:
Acuity
Color vision
Contrast sensitivity
Illumination
Low contrast acuity
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Since there is little experimental evidence on the influence of various stimulus factors on vernier acuity, functions relating vernier acuity to illumination have been obtained for two different exposure times and at three regions of the visible spectrum. An apparatus providing the necessary stimulus controls has been described in detail and the procedure is fully explained.
Vernier acuity, as measured by the reciprocal of the standard deviation of "alignment" setting, varies with illumination for both indefinitely long and for short exposures. At low brightness vernier acuity is low, rises rapidly with increase in illumination, and finally levels off at a constant level at high brightnesses.
Vernier acuity functions for short exposures are displaced downward and along the illumination axis relative to the function for long exposures. Thus maximum vernier acuity is never so high for short exposures and the maximum is reached at higher illuminations than with long exposures.
The relationship between vernier acuity and illumination for both long and short exposures is fitted by Hecht and Mintz's theoretical equation for visual acuity based on the brightness discrimination of the eye.
Variations in the functions with duration of exposure of the acuity object are interpreted in the light of the intensity-time relationship and the findings of Graham and Kemp on the effect of exposure time on brightness discrimination.
To investigate the influence of wave-length on vernier acuity, acuity vs. illumination functions have been found for red, yellow, blue, and white light. The experiments were carried out on two different apparatus.
The two sets of data obtained on the two apparatus show that all the functions are of the same shape, but that slightly different maximum acuities are reached with the different colored illuminations. Red gives the highest acuity, yellow next, white next, and blue least. When refractive correction is made to allow for sharp focusing in blue illumination, the highest acuities are found with this color.
It was concluded that wave-length of illumination is of some significance in vernier acuity, since higher acuities are found with nearly monochromatic light than with white. This improvement is perhaps caused by reduction of blurring of retinal images by restriction of the range of wave-lengths.
Notes:
Compare to Craik. Similar curves obtained, with asymptote above which increasing "illumination" did not increase acuity. Author states she cannot explain the order of acuities among colors tested in second experiment.
Authors: Ball, K. K., Beard, B. L., Roenker, D. L., Miller, R. L., & Griggs D. S.
Date: 1988.
Title: Age and visual search: expanding the useful field of view.
Pub: Journal of the Optical Society of America A, 5(12) 2210-2219.
Keywords:
Aging
Central vision
Driving
Foveal vision
Peripheral vision
Useful field of view
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
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 of 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, underestimated 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.
Notes:
Subjects responded to dual tasks, one central, one peripheral (10 to 30 from fixation). Most interesting finding was a practice effect, where performance improved on peripheral task after practice, and improvement persisted six months post-training. If confirmed and extended to performance on clearly driving-related tasks, this could have implications for testing and licensing.
Authors: Ball, K. & Owsley, C.
Date: 1991.
Title: Identifying correlates of accident involvement for the older driver.
Pub: Human Factors 33 (5), 583-595.
Keywords:
Aging
Driving
Holding: Full text (X) Abstract/Summary ( )
Abstract:
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.
Notes:
Authors built predictive model for accidents in older drivers based on regression analysis. Independent validation needed. Conclusions and ideas for further research are useful. Authors strongly support prospective studies.
Authors: Ball, K., & Rebok, G. W.
Date: 1994.
Title: Evaluating the driving ability of older adults.
Pub: Journal of Applied Gerontology, 13(1) 20-38.
Keywords:
Acuity
Aging
Central vision
Driving
Motion detection
Peripheral vision
Useful field of view
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
As a society, we have the responsibility of continuing to meet the transportation needs of a growing population of older adults. Simultaneously, we must recognize that driving is the preferred mode of travel among older citizens and that the ability to drive provides the mobility that many older adults rely on to maintain their independence. Although some older adults experience changes that make driving more difficult in later life, most older drivers retain their driving competence. With highly publicized accidents involving older drivers, however, the issue of age as a risk factor has received considerable publicity. Therefore, recent research has focused on isolating risk factors with this population. These studies have indicated that a measure of visual attention, the Useful Field of View, is particularly promising as a functional measure of driving risk. Furthermore, research has shown that the Useful Field of View can be expanded with training. These findings have important implications for developing interventions that might aid in maintaining the skills needed to drive safely into older age.
Notes:
Presents model proposing UFOV as predictor of accident risk for older drivers, based on retrospective study in which UFOV scores were able to predict history of accident involvement with some accuracy.
Author: Beilock, R.
Date: 1995.
Title: Schedule-induced hours-of-service and speed limit violations among tractor-trailer drivers.
Pub: Accident Analysis and Prevention, 27, (1), 33-42.
Keywords:
Driving
Fatigue
Safety
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
Driver fatigue is well recognized as an important causational factor in accidents involving long-distance truck drivers. Drivers may drive while fatigued for a variety of reasons. Important among these is the assignment of difficult or un reasonable delivery schedules. Using self-reported data, the frequency of violation-inducing schedules is estimated during their ongoing movement for a sample of 498 long-distance drivers. Assuming average legal speed limits of 55 MPH, 26% of the drivers were found to have violation-inducing schedules. Solo drivers, drivers hauling refrigerated loads, regular route drivers, and those with longer current trip distances are the most likely to have such schedules. Also estimated were total weekly work hours. Assuming average attained traveling speeds of 50 MPH, the average driver drives 46 hours per week and works a total of 58 hours.
Author: Beilock, R.
Date: 1988.
Title: 1988 RCCC Motor Carrier Safety Survey.
Pub: Alexandria, VA: Regular Common Carrier Conference.
Keywords:
Driving
Holding: Full text ( ) Abstract/Summary (X)
Abstract:
Safety on the highways is always a leading concern of the trucking industry. This report provides analyses and detailed results of the third RCCC Motor Carrier Safety Survey. In September 1988, 878 interviews were conducted with over-the-road truck drivers from the U.S. and Canada. These were the principal issues addressed: perceived speed limits, truck cruising speeds and compliance behavior; extent of driver training; extent of and truck drivers' opinions regarding drug and alcohol usage and testing; driver financial well-being, job intentions and employment alternatives; effectiveness of roadside inspections; role of driver fatigue in safety; off-Interstate access for larger combination rigs; acceptance and usage of certain safety devices (seat belts, antilock brakes, monitoring devices) and extent of radar detector usage.
Drivers (pp. 3-5). Average age, 41; average years of driving experience, 15.7. Average grade in school completed, 12, 52% completed high school; 18% completed at least one year of college. Ten percent belong to unions. For-hire carriers employ 52%, 27% are owner-operating under trip or permanent leases.
Equipment (pp. 5-8). Of the tractors in the 1988 Survey 52% are conventional (44% in the 1987 Survey); model years for 1984, 1985, 1986, and 1987 have progressively higher percentages of conventional tractors compared to cab-over-engine tractors. Single dry vans and single refrigerated vans account for 49% and 28% of all trailers, respectively. Single trailers 48 feet in length account for 57%.
Speed (pp. 10-13). Driver opposition to the 55mph speed limit approaches universality. Safety improved due to the 65 mph speed limit according to 59% of the drivers: 10% hold the opposite view. Rightly or wrongly, the large majority of truckers see the move to higher speed limits as both appropriate and safe.
Driver Training (pp. 13-19). Thirty percent received formal training; the least experienced are most likely to have had formal truck driver training. Where did they get trained? Private driver training schools: 51%; trained by companies that employed them: 28%; military: 21%. Surprisingly, it appears that drivers with formal training are somewhat more likely to have had accidents; the presence of formal training is not, in itself, indicative of a safer driver. There is a need for establishing and maintaining high standards so that drivers are taught accident-reducing skills, rather than given a false sense of security by just having had formal training.
Drug and Alcohol Testing and usage (pp.19-26). Drivers were asked for the percentage of their fellow drivers who regularly drive under the influence of illegal drugs. The mean response was 29%. Marijuana, "speed" and cocaine/"crack" were the most common illegal drugs used in the opinion of the respondents. Forty-three percent of the drivers indicate they have been tested for alcohol, up from 33% in 1987. Fifty percent had undergone drug testing, up from 38% in 1987. Support for mandatory random drug and alcohol testing among drivers remains high in 1988 (68%), albeit lower than in 1987 (73%).
Roadside Inspections (pp. 26-32). Median number of inspections per year: 3; 87% of the respondents have had at least one yearly inspection. Median delay per inspection: 20 and 30 minutes. Most truckers have favorable impressions of roadside inspections. When asked to rate on a scale with 10 as best, the average response on fairness is 7.0 and the average 6.9 on ability to get bad rigs off the road.
Driver Fatigue in Accidents (pp. 32-38). The average respondent claims that he/she can drive 10.6 hours before requiring an extended rest; 30% indicate that they can drive longer than 16 hours. Drivers estimate, on average, that 36% of truck accidents are due to driver fatigue. What to do about the driver fatigue problem? One third of the drivers indicate the need for greater (explicit) controls on those dictating the schedules -- the dispatchers, shippers, and receivers. Increased enforcement was the second most mentioned solution (16%).
Driver Shortage (pp. 39-45). Will drivers still be driving in 5 years? Just under one third indicate that they will not, with drivers over 50 years old nearly twice as likely as younger drivers to express such feelings. Reasons for leaving by those under age 50: 41% mention stress- and anxiety-related factors -- such as danger and tight schedules -- and being away from families at length; 27% say poor incomes; 21% mention stress from government agencies. To what occupations will they go? 21% to trucking-related occupations, like mechanic or dispatcher; 24% into other manual work professions such as carpentry, construction, and operating other types of vehicles; 19% say they'll be self-employed or in farming.
Off-Interstate Access (pp. 47-48). Just over one fifth of the drivers report at some time having pulled "twins." Of these drivers, over the past year, 15% pulled "twins" on roadways where they were not legal. Over four times as many truckers have at some time pulled 48-foot trailers compared to truckers who have pulled "twins." Of those with 48-footer experience, almost one third resort to driving on nondesignated roads. Georgia is the state that's most problematic about access.
Safety and Monitoring Devices (pp. 49-51). Seat Belts: Two fifths almost never use their seat belts and two fifths almost always use theirs; 34% favor a mandatory seat belt law and 53% are opposed. Antilock Brakes: 77% believe they have had some experience driving rigs with antilock braking systems. Of all drivers, 47% feel that antilock systems are safer than conventional braking systems; 24% are unsure or feel the systems are comparable; and 29% believe that conventional brakes are safer. Two thirds would oppose a law mandating the use of antilock systems on new rigs. Radar detectors: 62% of the drivers interviewed use radar detectors themselves, and the average respondent feels that 84% of all truck drivers use them; 94% of the respondents oppose a nationwide ban on radar detectors. On-board monitors: 12% of the respondents indicate that the tractor they were driving had an on-board monitoring device. Do drivers think that the mandatory installation of speed-and-driving-time-monitoring devices would improve safety? While only 28 percent say "Yes," 54% of those with monitoring devices say "Yes." Unlike a ban on radar detectors, most drivers are not philosophically opposed to a law requiring monitoring devices.
Notes:
This is the last year that this survey was conducted.
Authors: Bellamy, L. J., & Courtney, A. J.
Date: 1981.
Title: Development of a search task for the measurement of peripheral visual acuity.
Pub: Ergonomics, 24 (7) 497-509
Keywords:
Acuity
Peripheral vision
Visual field
Holding: Full text ( ) Abstract/Summary (X)
Abstract:
Results from 3 experiments with 27 18-56 yr olds indicate a relationship between peripheral visual acuity and search performance. It is suggested that use of this relationship can be made in assessing the relative extent of an individual's peripheral visual field (visual lobe) for target detection when visually screening them for industrial inspection tasks. A card sorting task involving visual search was developed that was shown to be sensitive to S differences in search speed. Speed of search correlated significantly with visual lobe area, but Ss' foveal acuities were not significantly related to search time. Test-retest reliability for Forms A and B of the card sorting task over a 1-wk period was r = .81 ( p < .001).
Authors: Berbaum, K. S., Kennedy, R. S., Williams, M. C., & May, J. G.
Date: 1985.
Title: A Survey of Vision Tests with Special Relevance for Military Jobs (Final Report for Phase I and Technical Proposal for Phase II).
Pub: Army Medical Research & Development Center and Essex Orlando, Technical Report EOTR 85-4.
Keywords:
Acuity
Contrast sensitivity
Driving
Dynamic acuity
Low contrast acuity
Motion detection
Spatial frequency
Static acuity
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract: Authors' Summary
Our dependence on seeing is a fact of everyday life; persons with superior visual function will typically perform better on visual tests. These relations, which clearly hold for the extremes of vision, are widely supported both anecdotally and in the literature, but the extent of relationship is not always well defined. The three military services have active research efforts to study whether visual test scores are related to operational performance. The number of visual tests available for study is very large, a need exists to summarize this information, and to synthesize the schematic literature and other findings for application to military jobs. As a first step in this endeavor we selected five visual functions that we believe are not only important for military performance but also, properly implemented, could be used to select or classify persons so that improved operational performance could be expected and better allocation made of the human resources. Initially we had considered reviewing only contrast sensitivity in Phase I, but decided that a better choice would be to delay that review until Phase II and to cover several areas in Phase I that are less well known and perhaps not as actively studied within Army laboratories but which, in our opinion, show good promise for being predictive of operational performance. Throughout our reviews we attended to the practical issues of testing large numbers of individuals reliably, accurately, and quickly, and included sections in our reviews describing the apparatus to be employed.
In Phase II we propose two different activities to be conducted in parallel: 1) to complete our taxonomy of visual processes and visual tests, and to produce a handbook which reviews all this material; and 2) to conduct formal analyses of the visual functions and processes which comprise disparate military jobs. The handbook would contain cross-referencing of all tests to the visual requirements of the various jobs. It is expected that the handbook will take two years to complete, and the final report will contain 25-40 in-depth reviews according to the number of visual processes surveyed. Each of these reviews would be the product of a nationally recognized authority, although all reviews will be carefully edited and rewritten by the Essex key personnel to assure consistency in content, style and format. A publisher has expressed strong interest in production and distribution of the work provided the materials can be "civilianized" to broaden the interest for commercial markets. Essex has agreed to underwrite the necessary costs of transliterating the Phase II final report into a handbook that civilian vision and eye care professional would find useful.
Notes:
Extensive inventory of vision tests, along with review of independent and dependent variables related to several visual functions.
Authors: Blakemore, C., & Campbell, F.W.
Date: 1969.
Title: On the existence of neurones in the human visual system selectively sensitive to the orientation and size of retinal images.
Pub: Journal of Physiology, 203, 237-260
Keywords:
Acuity
Contrast sensitivity
Low contrast acuity
Spatial frequency
Holding: Full text (X) Abstract/Summary ( )
Abstract: Authors' summary
1. It was found that an occipital evoked potential can be elicited in the human by moving a grating pattern without changing the mean light flux entering the eye. Prolonged viewing of a high contrast grating reduces the amplitude of the potential evoked by a low contrast grating.
2. This adaptation to a grating was studied psychophysically by determining the contrast threshold before and after adaptation. There is a temporary fivefold rise in contrast threshold after exposure to a high contrast grating of the same orientation and spatial frequency.
3. By determining the rise of threshold over a range of spatial frequency for a number of adapting frequencies it was found that the threshold elevation is limited to a spectrum of frequencies with a bandwidth of just over an octave at half amplitude, centered on the adapting frequency.
4. The amplitude of the effect and its bandwidth are very similar for adapting spatial frequencies between 3 c/deg. and 14 c/deg. At higher frequencies the bandwidth is slightly narrower. For lower adapting frequencies the peak of the effect stays at 3 c/deg.
5. These and other findings suggest that the human visual system may possess neurones selectively sensitive to spatial frequency and size. The orientational selectivity and the interocular transfer of the adaptation effect implicated the visual cortex as the site of these neurones.
6. This neural system may play an essential preliminary role in the recognition of complex images and generalization for magnification.
Authors: Bourdy, C., Cottin, F., & Monot A.
Date: 1991.
Title: Errors in distance appreciation and binocular night vision.
Pub: Ophthalmic and Physiological Optics, 11(4), 340-349
Keywords:
Binocular/Monocular
Distance judgment
Low contrast acuity
Night vision
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Studying binocular vergence in relation to luminance levels, we isolated two types of behaviour which may explain differences in distance appreciation:
1. Underestimation of distances in subjects with overconvergence in darkness.
2. Overestimation of distances in subjects with underconvergence in darkness.
Progression towards the limiting value of convergence varies from one individual to another for each mesopic and scotopic luminance level and for different experimental conditions: variable discrepancy between the observation distance and the tonic vergence distance, accommodative or fusional stimuli at varying degrees of eccentricity, mobile stimuli in the observer's peripheral field. The study of bipartition in depth of a given interval for different observation distances confirms the existence of two major categories of individuals. Over- or underestimation of the nearer subjective half correlates to the binocular dark convergence capacity of each individual. These findings may explain errors in distance appreciation for road users in night vision.
Notes:
Part of driving-related research program whose goals include determining "the spatial behavior of road users at night." Found considerable individual differences in convergence in darkness, associated with differences in depth and distance judgements. This work is related to the body of work on dark focus by Leibowitz and Owens.
Author: Brennan, D. H.
Date: 1985.
Title: Entry visual standards and ocular examination techniques for future fighter aircrew.
Pub: Agard Conference Proceedings No. 396, Medical Selection and Physiological Training of Future Fighter Aircrew, pg. 35-1 to 35-6
Keywords:
Acuity
Binocular/Monocular
Color vision
Contrast sensitivity
Glare
Spatial frequency
Standards
Visual field
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Summary: The visual tasks of future fighter aircrew are likely to increase both in magnitude and complexity. The increasing adoption of devices for visual enhancement and protection, even now, poses problems of integration with spectacles.
The visual standards required for initial selection for training as a pilot or navigator should, if numbers permit, be such that trained aircrew are unlikely to require a visual aid until presbyopia physiologically demands correction in the latter half of the fourth decade.
This paper will discuss the visual standards considered apposite for future fighter aircrew and the related ocular examination techniques both conventional and those designed to test such specialized ocular functions as stereopsis, glare resistance, dark adaptation, hue discrimination and modulation transfer function.
Notes:
This paper supports others suggesting broadening of areas of visual function to be tested.
Authors: Brouwer, W. H., Waterinck, W., Van Wolffelaar, P. C., & Rothengatter, T.
Date: 1991.
Title: Divided attention in experienced young and older drivers; lane tracking and visual analysis in a dynamic driving simulator.
Pub: Human Factors 33 (5), 573-582.
Keywords:
Aging
Attention
Driving
Holding: Full text (X) Abstract/Summary ( )
Abstract:
A simulated driving task that required the simultaneous execution of two continuous visual tasks was administered to 12 healthy young (mean age 26.1 years) and 12 healthy older (mean age 64.4 years) experienced and currently active drivers. The first task was a compensatory lane-tracking task involving a three-dimensional road display. The second task was a timed, self-paced visual analysis task, involving either a vocal or manual binary response to dot patterns projected within the road display. Using adaptive tasks, single-task difficulty was individually adjusted for each subject. To control for individual differences in attention allocation strategy, the dual task was performed according to three different sets of instructions based on the relative importance of each task. Compared with young adults, older adults showed a significantly decreased ability to divide attention. This effect was apparent in lane tracking and in the accuracy of visual analysis. The impairment of divided attention was less pronounced in the vocal condition than in the manual one. This suggests that difficulty in integrating responses may be an important determinant of poor dual-task performance in old age.
Notes:
Ongoing research program; generally consistent results across studies.
Author: Burg, A.
Date: 1968.
Title: Vision and driving: A summary of research findings.
Pub: Highway Research Record, Number 216, 1-12.
Keywords:
Acuity
Driving
Dynamic acuity
Low contrast acuity
Peripheral vision
Static acuity
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
To provide driver licensing administrators with heretofore unavailable information on which to establish effective vision-screening procedures for driver license applicants, a number of visual performance, personal, and driving habit characteristics of some 17,500 volunteer California driver license applicants were compared with their 3-year driving records (accidents and convictions). The vision tests included those for dynamic visual acuity, static visual acuity, field of vision, lateral phoria, low-illumination vision, glare recovery, and sighting dominance. Of these, dynamic visual acuity was most closely and consistently correlated with driving record, followed by static acuity, field of vision, and glare recovery. All relationships were in the "expected" direction, i.e., poor vision was associated with poor record. As expected, among all variables studied, age, sex, and average annual mileage play the largest role in influencing driving record. Accident and conviction frequencies increase with increasing mileage, are lower for females than for males, and are highest for the young age groups. Accident and conviction rates per 100,000 vehicle-miles decrease slightly with increasing mileage, are approximately the same for both sexes, and are highest for young drivers having the lowest rates. The report gives recommendations for additional research and suggests practical applications of the present findings.
Notes:
Based on records of 14,215 drivers. This early work is cited often in other papers.
Authors: Burg, A., & Coppin, R. S.
Date: 1966.
Title: Visual acuity and driving record.
Pub: Highway Research Record, Number 122, 1-6.
Keywords:
Acuity
Driving
Dynamic acuity
Low contrast acuity
Static acuity
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
The Institute of Transportation and Traffic Engineering at UCLA has for a number of years been conducting research on human factors in transportation. Within this general area considerable activity has been directed toward studying the visual requirements of the driving task. The California Department of Motor Vehicles, because of its responsibility for selecting individuals who should be licensed to drive a motor vehicle, also has a strong interest in knowing the visual requirements of driving, so that a more valid and reliable vision-screening procedure might be used.
It is not surprising, then, to find the Institute and the Department cooperating in a joint research venture whose purpose is to determine whether relationships can be found between how well a person sees and how well he drives, as reflected in his driving record. The U.S. Public Health Service is supporting a three-year research program to study the relationship between vision test scores and driving record. A preliminary report (1) presents a detailed description of the study as well as of the background research leading to it. The purpose of the present paper is to outline the general nature of the research program and to present the results obtained thus far from preliminary data analyses.
Notes:
Report from same study as Burg, 1968. Preliminary results only given here, show some relationship of dynamic acuity to sex, age, static acuity. Correlation of dynamic to static acuity decreases as target speed increases. See Burg, 1968 and other papers for later reports of this work.
Authors: Campbell, F. W., & Maffei, L.
Date: 1980.
Title: The influence of spatial frequency and contrast on the perception of moving patterns.
Pub: Vision Research, 21, 713-721.
Keywords:
Contrast sensitivity
Dynamic acuity
Low contrast acuity
Motion detection
Peripheral vision
Spatial frequency
Velocity
Holding: Full text (X) Abstract/Summary ( )
Abstract:
The perception of the apparent frequency of rotation of gratings of various spatial-frequencies and contrast is investigated. Increasing the spatial-frequency from 1 to 4 c/deg increases the perceived frequency of rotation. For higher spatial-frequencies, up to the limit of visibility, the perceived frequency of rotation decreases in inverse proportion to the spatial-frequency. At low contrast, near threshold, gratings are perceived to rotate very slowly and can actually appear to be stationary, hence the term "stopped motion". Above a contrast level of 0.05 the effects of contrast saturate, so that the apparent frequency of rotation equals the true frequency of rotation. If a rotating grating viewed by central vision is compared with an identical grating falling on the periphery of the visual field the latter is seen to rotate very much more slowly and indeed may appear to be stationary. If a rotating pattern consisting of small, randomly sited spots is compared with a similar target of large spots, the former is seen to rotate more slowly; the same being true for targets with only one spot thereon, providing they differ in size. Qualitative observations using gratings moving linearly appear to be as above. High spatial-frequency and low contrast gratings appear to move slower. Likewise an oscilloscope spot oscillating back and forth at a constant velocity appears to have a lower velocity in the peripheral field.
Notes:
Demonstration study looking at relationships between spatial frequency and apparent velocity or frequency of rotation. Needs to be extended to other types of motion, other situations.
Authors: Campbell, G., & Robson, J.
Date: 1968.
Title: Application of Fourier analysis to the visibility of gratings.
Pub: Journal of Physiology, 197, 551-566.
Keywords:
Acuity
Contrast sensitivity
Fourier analysis
Spatial frequency
Holding: Full text (X) Abstract/Summary ( )
Abstract:
1. The contrast thresholds of a variety of grating patterns have been measured over a wide range of spatial frequencies.
2. Contrast thresholds for the detection of gratings whose luminance profiles are sine, square, rectangular or saw-tooth waves can be simply related using Fourier theory.
3. Over a wide range of spatial frequencies the contrast threshold of a grating is determined only by the amplitude of the fundamental Fourier component of its wave form.
4. Gratings of complex wave form cannot be distinguished from sinewave gratings until their contrast has been raised to a level at which the higher harmonic components reach their independent threshold.
5. These findings can be explained by the existence within the nervous system of linearly operating independent mechanisms selectively sensitive to limited ranges of spatial frequencies.
Authors: Calabrese, O. J., Zwick, H.
Date: 1988.
Title: Meridian variations in spectral dark adaptation.
Pub: Letterman Army Institute of Research, Division of Ocular Hazards, Institute Report 372.
Keywords:
Acuity
Color vision
Dark Adaptation
Foveal vision
Impairments
Peripheral vision
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Spectral dark adaptation as a function of retinal meridian and of eccentricity was investigated by testing the absolute threshold dark adaptation curves for eight human volunteers at two retinal meridians. The horizontal and vertical meridians separately and together at eccentricities of 2 degrees and 16 degrees from a fixation point were studied. A microprocessor-operated dark adaptometer was used, and analysis of variance was performed on the data. The study indicated that meridian differences in the dark-adapted retina exist and that the horizontal meridian is more sensitive than the vertical meridian when the retina is tested at 16 degrees with medium wavelength light. This may indicate meridian differences in photoreceptor distribution.
Authors: Cavallo, V. & Laurent, M.
Date: 1988.
Title: Visual information and skill level in time-to-collision estimation.
Pub: Perception, 17, 623-632.
Keywords:
Binocular/Monocular
Driving
Event perception
Time to collision
Velocity
Visual field
Holding: Full text ( x ) Abstract/Summary ( )
Abstract:
Previous studies on the visual origin of time to collision (TC) information have demonstrated that TC estimates can be based solely on the processing of target expansion rate (optic variable ). But in the simulated situations used (film clips), there was little reliable information on speed (owing to reduced peripheral vision) and distance (owing to the absence of binocular distance cues) available. In order to determine whether these kinds of information are also taken into account, it is necessary to take an approach where the subject receives a more complete visual input. Thus an experiment conducted on a circuit under actual driving conditions is reported. Experienced drivers and beginners, who were passengers in a car, had to indicate the moment they expected a collision with a stationary obstacle to take place. Subjects were blindfolded after a viewing time of 3 s. The conditions for speed evaluation, (normal vs. restricted visual field) and distance evaluation (binocular vs. monocular vision) by subjects were varied. The approach speed (30 and 90 km h-1) and actual TC (3 and 6 s) were also varied. The results show that accuracy of TC estimation increased with (I) normal visual field, (ii) binocular vision, (iii) higher speeds, and (iv) driving experience. These findings have been interpreted as indicating that both speed and distance information are taken into account in TC estimation. They suggest furthermore that these two kinds of information may be used differently depending on the skill level of the subject. The results are discussed in terms of the complementarity of the various potentially usable visual means of obtaining TC information.
Notes:
All subjects under all conditions underestimated time to collision. Binocular vision improved accuracy of estimation only at lower speeds, (confounded here with distance to target) where estimation was worst. Speed effect not found under normal visual conditions.
Authors: Charman, W., & Tucker, J.
Date: 1977.
Title: Dependence of accommodation response on the spatial frequency spectrum of the observed object.
Pub: Vision Research, 17, 129-139.
Keywords:
Accommodation
Contrast sensitivity
Dark (empty field) focus
Spatial frequency
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Experiments are described in which the monocular, steady-state, accommodation response to sinusoidal grating targets was assessed as a function of the spatial frequency of the grating and its vergence at the eye, using a laser optometer. At all levels of stimulus, the response is found to be dependent upon the grating frequency. At very low spatial frequencies the response is often substantially in error and is closely related to the accommodation exercised by the observer when viewing an empty field. At higher frequencies the response becomes more accurate and its exact value is probably dependent upon the observing conditions and upon the ocular aberrations and other properties of the observer. Further experiments with Snellen targets suggest that the accommodation to a target with a complex spatial frequency spectrum cannot be predicted from a knowledge of that spectrum and of the observer's response to its component frequencies, under the same viewing conditions. The significance of the findings to theories of accommodation is indicated.
Authors: Chernysheva, S. G., Rozenblyum, Y. Z., Yachmeneva, E. I., Eremin, V. M., Utkin, A. V., & Eliseeva, L. A.
Date: 1993.
Title: Vision and Driving.
Pub: Human Physiology, 19, (1), 80-84.
Keywords:
Acuity
Color vision
Contrast sensitivity
Driving
Dynamic acuity
Impairments
Motion detection
Peripheral vision
Spatial frequency
Standards
Time to collision
Velocity
Vision testing
Visual field
Holding: Full text (English Translation) Abstract/Summary ( )
Abstract: Authors' conclusion:
Thus, the problem of vision and transport has not been sufficiently investigated. The methods of visual function examination used in clinics, are most often traditional and not suitable for the evaluation of a driver's professional fitness; the criteria of driving fitness being ill-founded and contradictory. So elaboration of ergophthalmological methods of visual function examination and of criteria of professional fitness of transport operators is of vital importance.
Quote: Yu. Z Rozenblum proposes the following functions corresponding to a driver's tasks be examined: detection and recognition of objects moving in the visual field; tracking of a moving object; prediction of point of intersection of moving and motionless objects; resolution under conditions of poor visibility, low luminosity, and blinding light sources.
Notes:
Review and comment article, not experimental work. Most references are to Russian articles, but some to US and European, especially military work. Valuable chiefly to show that scientists outside US are concerned about driver testing and are concluding that it needs to be made more task-relevant.
Authors: Cohen, A. S.
Date: 1987.
Title: Nutzbarer Sehfeldumfang und seine Variation in Feldsituationen.
Pub: Zeitschrift fur Experimentelle und Angewandte Psychologie, 34 (1), 17-37.
Keywords:
Driving
Peripheral vision
Useful field of view
Velocity
Visual field
Holding: Full text (in German) Abstract/Summary ( )
Abstract: (English abstract from PsychInfo)
The useful field of vision of a driver and its variation was investigated using a specially equipped car on a highway at velocities ranging from 80 to 130 km/h. The 22 subjects were experienced policemen. Their task was to detect signals mounted on the windshield and to respond as quickly as possible. The retinal locus of each signal was determined post hoc, using a new method described in this paper. The criteria for data evaluation were the rate of detected signals and the corresponding reaction time. The results showed that the size of the useful field of vision was not influenced by the speed of traveling. This finding contradicts the postulated tunnel vision at increased speed. However, the size of the useful field of vision decreased when the driver deviated from the prescribed speed of traveling, driving either too fast or too slow. It is assumed that the resulting internal workload exhausted the drivers' capacity and consequently caused perceptual narrowing, which is a peripheral manifestation of central overload. The results are discussed in terms of capacity limits in relation to the drivers' task demands.
Author: Craik, K.
Date: 1939.
Title: The effect of adaptation on visual acuity.
Pub: British Journal of Psychology, 29, 252-266.
Keywords:
Acuity
Adaptation
Illumination
Low contrast acuity
Holding: Full text (X) Abstract/Summary ( )
Abstract: Author's Introduction
It was found by Mellone and Rawdon-Smith (1935, unpublished), and in a more extended investigation by the present author (1938), that visual adaptation has a considerable effect upon intensity discrimination. The differential threshold was found to be lowest when tested at the same illumination to which the eye was adapted, and to be raised considerably where these 'test' and 'adapt' illuminations were widely different.
It seemed that a similar investigation of visual acuity might throw some light on the relation between this and intensity discrimination. A positive result was to be anticipated from the experiments of Lythgoe (1932) in which acuity was diminished by a surrounding field, except when that field had approximately 1/10th the brightness of the smaller field containing the test object; for spatial and temporal proximity of an adapting field appear in general to have very similar effects.
Notes:
Classical work, but test conditions and measurement units are not those commonly used today. Curves were obtained for acuity vs. illumination, given equal adapting and test illumination levels (negatively accelerating increase asymptoting at about 100 e.f.c), and for acuity vs. illumination, given varying adaptation conditions (inverted u-shape curves, with best acuity near adapting illumination except at very low adapting levels).
Unit of illumination, e.f.c., appears to be "equivalent foot candles" (p.256).
Authors: Decina, L. E., Breton, M. E., & Staplin, L.
Date: 1991.
Title: Visual disorders and commercial drivers (Report No.DTFH61-90-C-00093).
Pub: Washington, DC: U. S. Department of Transportation, Federal Highway Administration, Office of Motor Carriers.
Keywords:
Acuity
Aging
Amblyopia
Binocular/Monocular
Central vision
Color vision
Contrast sensitivity
Driving
Dynamic acuity
Glare sensitivity
Impairments
Low contrast acuity
Peripheral vision
Spatial frequency
Standards
Static acuity
Useful field of view
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
The objectives of the project were to reassess the adequacy of the current Federal vision standards for CMV operators (49, CFR, 391.41(b) (10), 1985). The technical approach included doing a critical review of existing literature; providing a preliminary draft of recommendations; preparing a risk assessment of visual criterion levels proposed; conducting a workshop to review draft recommendations with expert industry and vision panelists and providing a summary of the project with final recommendation.
A review and critical evaluation of the most significant scientific research, which investigated the vision performance of passenger and commercial drivers, revealed no conclusive evidence to support definitive changes to the current standard. However, it was deemed important to include visual acuity and visual fields requirements for the standard. Based on the critical review of the literature, opinion surveys, and workshop results collected from panelists representing the vision industry field, the following recommendations were made: distant visual acuity of at least 20/40 in each eye without corrective lenses or visual acuity separately corrected 20/40 or better with corrective lenses, distant binocular acuity of at least 20/40 in both eyes with or without corrective lenses, field of vision of at least 120 degrees in each eye measured separately in the horizontal meridian, and the ability to respond safely and effectively to colors of traffic signals and devices showing standard red, green, and amber. No test for color vision is required. The instructions to perform and record the visual examination were extensively revised. Identification of the type of equipment, the stimuli needed to conduct the testing, and instructions on how to perform the tests were added. The full description of the definition and testing procedures of the standard is provided in the body of the report. In addition, revisions were made to the list of visual disorders and impairments to be noted on the exam form.
Notes:
This report is useful background, provides history, and sets a baseline for the current vision standard.
Authors: Dichgans, J., & Brandt, T.
Date: (1978).
Title: Visual-vestibular interaction: Effects on self-motion and postural control.
Pub: In Held, R., Leibowitz, H. W., & Teuber, H.- L. (Eds.), Handbook of Sensory Physiology, VIII. Heidelberg: Springer.
Keywords:
Event perception
Motion detection
Relative motion
Self-motion
Posture
Situational awareness
Vection
Velocity
Vestibular effects
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
Authors' introduction: The sensation of self-motion is a common visual illusion which allows inferences concerning visual-vestibular interaction. It may be perceived while gazing at moving clouds, streaming water, or when a train moves on the adjacent track in a railway station. This compelling sensation of body movement can even affect postural balance. On first approaching the problem, a psychologic explanation could be suggested in the sense of Helmholtz's (1896) Urteilstäuschung. One might assume that these illusions are inferences based upon the conscious or unconscious assumption of a stable environment, so that when the environment does in fact move, the observer infers that he himself is moving. This interpretation would be consistent with the individual's past experience as the entire visual surround seldom moves uniformly under natural conditions unless the body moves relative to the earth.
However, as in the case of other illusions, physiologic explanations may be more rewarding than psychologic ones. As Purkinje suggested, visual illusions reveal the truth about the visual system (Gesichtstäuschungen sin Sinneswahrheiten). An analysis consistent with his view takes into account that in the visually induced perception of self-motion, the term illusion only applies to the case in which the surround moves exclusively, and recognizes that identical visual stimulation occurs during actual body motion in which instance the same physiologic mechanism may maintain the veridical perception of body motion at constant velocity. The assumption of such a mechanism of visual-vestibular interaction, common to both illusion and veridicality, may lead to a better understanding of sensory control of body movement and spatial orientation than the psychologic explanation.
Under natural conditions with the eyes open, active as well as passive body motion is adequately perceived, be it of constant or varying velocity (Fig. 1 B). While riding in a vehicle with the eyes closed, however, the deficiencies of the vestibular system become apparent. Vestibular information about motion then is evoked only through acceleration or deceleration and dies out as the cupulae within the semicircular canals, or the otoliths, progressively return to their resting position during constant velocity. Consequently, constant velocity in the dark cannot be discriminated from rest for any extended period of time. Due to this lack of sustained labyrinthine information about constant velocity, deceleration from constant velocity is misinterpreted as acceleration in the opposite direction (Fig. 1 A). These two observations support the assumption that visual inputs are directly integrated with vestibular afferents. If so, the visual responses overcome the vestibular organ's deficiency for constant velocity discrimination. Such a concept might also entail inborn neuronal networks for visual-vestibular interaction rather than solely experience and learning. Thus, the aforementioned illusion (see also Fig. 1 C) may in fact indicate a functionally important mechanism of multisensory interaction.
This chapter follows this line of reasoning. First, psychophysic evidence is presented indicating that motion-vision plays a predominant role not only in the perception of self-motion but much more generally, in dynamic spatial orientation and postural control. It will become apparent from this that visual and vestibular information must converge on the same locus somewhere in the brain where they are integrated to provide the basis for a unitary model of dynamic and static orientation in space. Second, neurophysiologic experiments, most of which were designed to test this postulate, are discussed. The results demonstrate the existence of at least one site of interaction within the central nervous system which is common to all vertebrate species tested so far: the vestibular nuclei.
In order to discuss the psychophysical evidence, it is necessary to first describe the various sorts of subjective localization and motion perception with their related reference systems, as well as the terminology.
Notes:
Detailed examination of many aspects of visual-vestibular interactions, vection, related topics. Extensive literature review.
Authors: Ebenholtz, S.
Date: 1976.
Title: Additivity of after effects of maintained head and eye rotations: an alternative to recalibration.
Pub: Perception & Psychophysics, 19, 113-116.
Keywords:
Eye position
Head position
Positional aftereffects
Potentiation
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Seven groups of 10 subjects each were exposed to various combinations of left and right head and eye rotations for a period of 10 min. Both head and eye produced significant aftereffects of prior position as measured by pointing at a visible target with the unseen hand, but there was no significant interaction. Thus, aftereffects of sustained head and eye rotation were shown to be additive and to account fully for the results of Craske and Crawshaw (1975). Eye muscle potentiation rather than recalibration may be assumed to be the cause of the altered direction of gaze resulting from exposure to displacing prisms.
Notes:
Argues that muscular potentiation resulting from sustained eye or head rotation can account for observed aftereffects on visual localization. This is in opposition to theory of "recalibration" to account for same observed effects.
Authors: Ebenholtz, S. M., & Fisher, S. K.
Date: (1982).
Title: Distance adaptation depends upon plasticity in the oculomotor system.
Pub: Perception and Psychophysics, 31, 551-560.
Keywords:
Accommodation
Binocular/Monocular
Distance adaptation
Phoria
Vergence
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
Maintaining binocular fixation on a target at 20 cm in the absence of secondary cues to distance produced changes in apparent distance and lateral phoria. Positive lenses of 0, .5, 2.0, 3.5, and 5.0 spherical diopters (SD) were used to manipulate the level of accommodative convergence in force during the period of maintained fixation. An inverse relationship was found between the stimulus to accommodation and the magnitude of the induced esophoria, the phoria being linearly related to an increase in apparent distance. The distance aftereffect obtained in the condition with the lowest net accommodative stimulus (i.e., 0 D) equaled that typically produced by based-out prism adaptation with full secondary cues to distance available. In a second experiment, subjects walked through a well-lit hallway while viewing through a pair of 5 base-out prisms. It was shown that increasing the stimulus to accommodation by adding negative lenses of 0, 1.5, 3.5, and 5.5 SD reduced the adaptive change in apparent distance, as well as the change in phoria produced by the conventional base-out prism adaptation paradigm. It was concluded that a change in the resting tonus of the disparity vergence system underlies such adaptation, rather than recalibration of the oculomotor cues to distance. Monocular exposure data indicated that a small change in the tonus control for the accommodative system may be present as well.
Authors: Epstein, W., & Cody, J .W.
Date: 1980.
Title: Perception of relative velocity: A revision of the hypothesis of relational determination.
Pub: Perception, 9, 46-60.
Keywords:
Dynamic acuity
Velocity
Holding: Full text (X ) Abstract/Summary ( )
Abstract:
The conventional formulation of the hypothesis of relational determination asserts that the perceived relative velocities of two or more objects depend upon their relative rates of displacement with respect to stationary referents in the visual field. Experiment 1 showed that this formulation is too restrictive by demonstrating the transposition-of-velocity effect under conditions in which two light spots moved in the absence of static visible contours and traversed unequal path lengths. Experiment 2 showed that angular velocity per unit of relative angular extent, and not relative linear or perceived extent, of the respective motion paths influences perceived relative velocity in nonarticulated space. The retinal dimensions of static visible frameworks were shown in experiment 3 to influence perceived relative velocity in a direction consistent with the conventional formulation of the relational-determination hypothesis, but the weight of the evidence suggested a reformulation along the following lines: the perceived relative velocities of two objects are significantly affected by the proportions of the retinal projections of the respective movement fields traversed by the two objects in the same unit of time, even when the motion fields consist only of the objects' motion paths.
Notes:
This article concentrates almost entirely on testing opposing theories of velocity perception.
Authors: Fejer, T. P. & Girgis, R.
Date: 1992.
Title: Night myopia: implications for the young driver.
Pub: Canadian Journal of Opthamology, 27, (4), 172-176.
Keywords:
Acuity
Aging
Amblyopia
Contrast sensitivity
Dark focus
Driving
Impairments
Low contrast acuity
Luminance
Myopia
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
A total of 380 randomly selected patients aged 16 to 80 years, who did not have eye disease underwent testing for night myopia between August and October 1989 with a laser speckle generator under both photopic and scotopic conditions. For the first 308 subjects, the speckles were continuously run, and for the next 72 subjects a timer was used to minimize the accommodative stimulus. An increase in myopia of 0.75 dioptres or more from the photopic to the scotopic state, equivalent to a visual acuity of 20/45 or less, was considered indicative of night myopia. Overall, 17% of the subjects were found to have night myopia. Of the 26 subjects aged 16 to 25 in the timer group, 38% had night myopia of 0.75 D or more, 23% had night myopia of 1.00 D or more, and 4% had night myopia of 2.50 D, which is equivalent to an acuity of 20/265. The results indicate that driving in the dark could create visual difficulties for certain younger patients that a night myopic correction would eliminate.
Author: Fox, M. D.
Date: 1988.
Title: Elderly drivers' perceptions of their driving abilities compared to their functional visual perception skills and their actual driving performance.
Pub: Physical and Occupational Therapy in Geriatrics, 7(1-2) 13-49.
Keywords:
Aging
Color vision
Contrast sensitivity
Driving
Dynamic acuity
Impairments
Peripheral vision
Standards
Static acuity
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
The rationale of occupational therapy is to help individuals develop and function independently within their environment. The privilege of driving affords people one aspect of independence by serving as a link for the accomplishment of other daily living tasks. Although evidence suggests an age related decline in the skills needed for safe driving, especially after age 55, the clinical predictors of driving performance are relatively unknown. This study examined the elderly drivers' perceptions of their driving abilities, compared to their clinically tested functional skills in the area of visual perception, and their actual in-car driving performance. The specific skills assessed included peripheral visual field, depth perception, color sensitivity, static visual acuity, dynamic visual acuity, and figure-ground discrimination. The comparisons were examined by the chi-square and analysis of variance (ANOVA) statistical procedures to determine whether a significant difference existed among the variables. A population sample of 115 males, 65 years and older, were selected from an outpatient clinic at the Veteran's Administration Hospital in Richmond, Virginia.
Results indicated that clinically tested visual perception skills and actual in-car driving performance can be predictive based on left and right peripheral vision, and brown/green color sensitivity. This study also indicated that people generally tend to over-rate their driving abilities. It is believed that a larger sample and some testing instrument changes could yield more significant results. Limitations of this study and ideas for future research are provided.
Author: Gallwey, T.
Date: 1982.
Title: Selection tests for visual inspection on a multiple fault type task.
Pub: Ergonomics, 25 (11) 1077-1092.
Keywords:
Acuity
Peripheral vision
Useful field of view
Vision testing
Visual field
Holding: Full text ( ) Abstract/Summary (X)
Abstract:
Although individual differences between inspectors is the most significant factor in differences in inspection performance there are no suitable selection tests. The task was analyzed to indicate the required mental characteristics, and from this a battery of 10 selection tests was devised. These were used with a simulated task to include the search and decision components of inspection. Presentation was by sets of slides that contained 2, 4, or 6 fault types; slides were classified as fault free, acceptable fault, or reject. 48 college students and 18 industrial inspectors (mean age 34.8 yrs) participated. A multivariate analysis of covariance showed no difference between the student and industrial Ss. The best predictor was a simplified version of the task. Good predictive ability was obtained with the Group Embedded Figures Test; other good predictors were lobe size and mental imagery. If these tests were not used, good predictive ability was obtained with a subset of the WAIS, Eysenck Personality Inventory Extraversion scale, and the Gordon Test of Visual Imagery Control.
Author: Ginsburg, A. P.
Date: (1984).
Title: Visual form perception based on biological filtering.
Pub: In Spillmann, L., & Wooten, B. R., (Eds.), Sensory Experience, Adaptation, and Perception. Hillsdale, N.J.: Erlbaum. pp. 53-72.
Keywords:
Acuity
Contrast sensitivity
Form perception
Illusions
Spatial frequency
Vision testing
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
A filtering approach to understanding visual perception is shown to provide a framework for understanding certain aspects of how we see contrast, size, and form in simple gratings and letters as well as more complex visual illusions and portraits. Gestalt laws of closure, wholeness, proximity, and similarity are demonstrated using filtered images. Complex variations in the perceived magnitude of Müller-Lyer illusions are well predicted from computer data based on biological filtering. A physics of form perception is used to relate the detection and identification of Snellen type letters to individual contrast sensitivity functions. These results suggest that biologically based filtering and linear systems analysis, typified by Fourier techniques, can provide important tools with which to probe the foundations of our visual world.
Notes:
Basic statement of Ginsburg's theories, applied to well-known visual perceptual phenomena.
Author: Ginsburg, A. P.
Date: 1981.
Title: Proposed new vision standards for the 1980's and beyond: Contrast sensitivity (AFAMRL-Transparency-80-121).
Pub: Wright-Patterson Air Force Base, Ohio: Air Force Aerospace Medical Research Laboratory, Aerospace Medical Division, Air Force System Command.
Keywords:
Acuity
Contrast sensitivity
Spatial frequency
Standards
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Present visual standards are generally based on the observer's ability to see small high contrast black and white letters or symbols. Current research shows that such vision tests are not adequate to evaluate an individual's target detection and recognition capability over ranges of target size and contrast used in real situations. New vision tests are being developed that use the observer's report of the visibility of sine-wave gratings (that look like fuzzy bars) to assess visual capability with much more sensitivity than that of standard tests. The new tests, called contrast sensitivity, assess vision using the same method used to assess hearing. Just as hearing tests use sound intensity and temporal frequency to measure audiometric sensitivity, contrast sensitivity tests use contrast and spatial frequency to measure visual sensitivity. Because standard eye charts do not change contrast, they cannot measure vision sensitivity to any except the smallest size symbols. The relationship between contrast sensitivity and eye charts will be discussed using normal and abnormal vision. Although standard eye charts are useful to create an in-focus image in the back of the retina, contrast sensitivity techniques are needed to measure the next physiological state that determines the observer's response to that image. Data are presented that reveal individual differences in contrast sensitivity among normal observers that have definite implications for visual performance in operational environments. Since these differences in visual sensitivity can relate to detection and recognition ranges, these data can then be transformed into time to perform certain tasks and lead naturally towards visual standards being based on task performance under operational conditions. It is suggested that contrast sensitivity data be obtained in parallel with conventional vision tests to begin creating visual standards that relate to observer capability over the full range of operational environments.
Notes:
This work serves as background to the pubs looking at ability of contrast sensitivity and other tests to predict task performance.
Authors: Ginsburg, A. P., Cannon, M. W., Jr., & Nelson, M.
Date: (1980)
Title: Suprathreshold processing of complex visual stimuli: Evidence for linearity in contrast perception.
Pub: Science, 208, 619-621.
Keywords:
Contrast sensitivity
Spatial frequency
Vision testing
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
Magnitude estimation experiments show that perceived contrast for both sine and square waves is a linear function of stimulus contrast. The suprathreshold sine: square ratio required for equal perceived contrast derived from these data was verified by contrast matching experiments. These findings imply a high degree of linearity in suprathreshold visual processing of contrast.
Notes:
This work was designed to answer questions about contrast sensitivity functions above threshold range. Showed nearly constant sine/square ratio for equal judged contrast at above-threshold contrasts, for spatial frequencies above about 1 c/deg, above contrast value of 0.1.
Authors: Ginsburg, A. P., Evans, D. W., & Cannon, M. W. Jr.
Date: 1984.
Title: Large-Sample Norms for Contrast Sensitivity.
Pub: American journal of Optometry and Physiological Optics, 61, 80-84
Keywords:
Acuity
Contrast sensitivity
Standards
Static acuity
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
A portable microprocessor-controlled instrument automatically measured the static and dynamic contrast sensitivity functions (CSF's) of 265 observers for a normal population at the Dayton Air Fair and Air Force Museum. Repeat measures for six observers taken 6 months later show small, nonsystematic differences from original measurements. Median values of contrast sensitivity as well as regions encompassing 75 and 90% of our sample are shown.
Notes:
Provides a beginning for the collection of population norms. Note that refractive state of subjects was not equated; subjects used their normal corrections for all testing. Subjects were self-selected volunteers; authors excluded those with history or evidence of pathology.
Authors: Ginsburg, A. P., Evans, D. W., Sekuler, R. & Harp, A.
Date: 1982.
Title: Contrast sensitivity predicts pilots' performance in aircraft simulators.
Pub: American Journal of Optometry and Physiological Optics, 59, 105-109.
Keywords:
Acuity
Contrast sensitivity
Spatial frequency
Pilot performance
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Contrast sensitivity was found to be better than visual acuity for predicting a pilot's ability to detect a small, semi-isolated, air-to-ground target. Eleven instructor pilots had their acuity measured by both conventional and contrast sensitivity methods. Scotopic contrast sensitivity showed the highest correlation with slant detection range (0.83). Conventionally determined visual acuity proved to be a poor predictor of a pilot's ability to detect a small low contrast target.
Notes:
One more piece of evidence for predictive validity of contrast sensitivity, but does not directly address driving. This article concentrates on target detection, which may be more generalizable to driving tasks than bombing accuracy or aircraft landing proficiency.
Authors: Good, M. C., & Baxter, G. L.
Date: 1986.
Title: Evaluation of short-range roadway delineation.
Pub: Human Factors, 28 (6), 645-660
Keywords:
Acuity
Driving
Low contrast acuity
Peripheral vision
Useful field of view
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
A distinction is drawn between long- and short-range delineation, the latter being provided to aid the driver in tracking the roadway at night and under poor visibility conditions. A quasi-linear describing function approach is employed to represent the driver as a sensor and controller, and it is hypothesized that reductions in the quality of the driver's visual field will be reflected by an increase in the level of the "remnant" (interpreted in part as visual observation noise).
Experiments were performed on a rural road, to which a variety of delineation treatments were applied, using a vehicle that permitted the identification of driver-vehicle describing functions as subjects negotiated the test course. The results are generally supportive of the experimental hypothesis, with the describing function parameters yielding evaluations of delineation treatments that are consistent with each other and with subjective ratings of task difficulty.
Authors: Gurgold, G..D., & Harden, D. H.
Date: 1978.
Title: Assessing the driving potential of the handicapped.
Pub: The American Journal of Occupational Therapy, 32, (1), 41-46.
Keywords:
Driving
Impairments
Vision Testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
With a knowledge of available driving aids, the physical requirements needed to drive, the cognitive and perceptual deficits and their relationship to driving, the therapist should be able to make an early assessment of a client's driving potential. Other factors such as sensation, visual acuity, peripheral vision, distance judgment, reaction time, and spasms should not be overlooked in the preliminary driving evaluation.
Through the development of the Servo-hand control, physical requirements needed for driving have been reached. C-5 quadriplegic persons and other severely disabled individuals who cannot apply adequate force to drive with conventional hand controls are thus enabled to drive.
Authors: Held, R.
Date: 1968.
Title: Dissociation of visual functions by deprivation and rearrangement.
Pub: Psychologische Forschung, 31, 338-348.
Keywords:
Ambient vs focal
Analysis of form
Localization
Orientation
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Deficiency in visually-guided behaviors is the dominant effect of rearing kittens from birth without patterned visual stimulation of the two eyes. Following such deprivation, form discrimination is found relatively intact when the effects of the deficient orienting behavior are eliminated from the testing procedure. Recent experimental analyses implicate visual feedback contingent upon movement in a normal environment as the condition responsible for the losses in visually guided behavior produced by deprivation of patterned stimulation. Using the techniques of these experiments, the two eyes may be dissociated with respect to their ability to control movement but not in their performance of shape discrimination. Related research on adaptation to optical rearrangement has shown a high degree of lability in visually-guided behavior but only limited modifiability in perception of shape. It is suggested that the modification of a shape that does occur results from altered localization of its parts in space. The measurable modification of shape is limited by the fixedness of the pattern analyzing system. Certain implications for the earliest development of shape discrimination are drawn.
Notes:
Defense of "two modes of processing" concept. Classic early work.
Authors: Henderson, R. L., & Burg, A.
Date: 1974.
Title: Vision and audition in driving.
Pub: Santa Monica, CA: System Development Corporation.
Keywords:
Acuity
Driving
Dynamic acuity
Foveal vision
Low contrast acuity
Motion detection
Peripheral vision
Static acuity
Useful field of view
Vision testing
Visual field
Holding: Full text ( ) Abstract/Summary ( x )
Abstract:
A systematic analysis was made of the visual and auditory requirements of automobile and motorcycle driving which resulted in the identification of visual performance parameters that appear important to driving but that are not currently considered in the visual screening of driver license applicants. These include such parameters as perception of motion, dynamic performance of the total visual system, visual performance under low levels of illumination or in the presence of glare, and useful peripheral vision. The analysis did not identify similar requirements of auditory performance.
A device was designed and constructed to test performance on the new visual functions as well as on selected conventional measures. Performance on these tests was measured on 669 licensed California drivers and compared with past accident record. The results show that poor performance on several of the new vision tests is associated with poor driving record. Further, it was shown that some vision test scores serve as better predictors of accident involvement than such measures as age, sex, annual mileage or other biographical variables generally considered to be the best available predictors.
It is concluded that if the results of the study are verified and cross-validated on a much larger sample of the driving population, a basis will exist for developing and implementing a standardized visual screening program for driver license applicants that could contribute to improving highway safety.
Notes:
Early study, background for later papers in this series.
Author: Hess, R.
Date: (1984).
Title: Uses and abuses of assessing contrast threshold functions for anomalous vision.
Pub: In Spillmann, L., & Wooten, B. R., (Ed.), Sensory Experience, Adaptation, and Perception. Hillsdale, NJ: Lawrence Erlbaum Associates. pp. 633-650.
Keywords:
Acuity
Amblyopia
Contrast sensitivity
Foveal vision
Impairments
Spatial frequency
Supra-threshold vision
Vision testing
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
The contrast sensitivity approach has enjoyed much success in its recent applications to anomalous vision. The uses, abuses, limitations and extensions of this approach are detailed using examples of amblyopias from acquired (organic) as well as developmental (functional) origin. This approach is seen to extend our assessment of visual function and to have greater sensitivity than acuity. We are, however, severely limited in what we can say of the perceptual consequences using this approach for two reasons. First, sensory thresholds are rather special points on our sensory scale and second, they monitor a rather peripheral aspect of visual function.
Notes:
Notes both usefulness of CSF testing for certain diagnostic purposes, and limitations of such testing for assessment of visual function. Examples of problems: Cites evidence of differences between threshold and supra-threshold measures. Some impaired subjects show elevated thresholds with near-normal supra-threshold function. Some subjects can detect gratings, but show anomalous vision at detected frequencies, based on report of what is seen and on studies of phase discrimination. Discusses implications for testing of useful vision.
Authors: Hills, B. L., & Burg, A.
Date: 1977.
Title: A reanalysis of California driver vision data: General findings (Transport and Road Research Laboratory Report 768).
Pub: Crowthorne, Berkshire, U. K.: Transport and Road Research Laboratory.
Keywords:
Acuity
Aging
Driving
Dynamic acuity
Vision testing
Visual field
Holding: Full text ( ) Abstract/Summary ( x )
Abstract:
Data on over 14,000 drivers from the 1967 California driver vision study have been reanalyzed with a view to establishing their implications for driver vision standards. For the main analysis the sample was divided into four age groupings: under 25, 25-39, 40-54, and over 54.
The most consistent result throughout the study has been the failure to find a direct relationship between poor visual performance and high accident rates for young and middle-aged drivers. For the over 54 age group, Dynamic and Static Visual Acuity showed the most consistent relationship with accident rates but for an individual driver their accident prediction value remained very low. A more detailed age analysis failed to define more precisely the age at which these relationships develop. No evidence was found to support the use of Total Visual Field as a driver screening test. The results for two tests of night vision were regarded as inconclusive for the Over 54 age group. For the same nominal standard of binocular static visual acuity, the Ortho-Rater screener was found to fail markedly fewer drivers than the Snellen wall chart. The implications of varying the cut-off scores for each test were investigated, and the suggestion made that perceptual rather than sensory tests with greater accident predictive power would be needed before acceptable alternative screening methods could be specified for driver licensing purposes.
Notes:
Authors argue for "perceptual rather than sensory tests" of vision for drivers.
Authors: Janke, M. K.
Date: 1990.
Title: Safety effects of relaxing California's clean-record requirement for driver license renewal by mail.
Pub: Accident Analysis and Prevention, 22 (4), 335-349.
Keywords:
Driving
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
A pilot program was established in California in 1982 authorizing mail renewal of driver licenses for persons under age 70 lacking clean (accident- and conviction-free) 4-year driving records, but showing clean 2-year records at selection. Such drivers constitute about 14% of California's renewal population, or about 500,000 renewees per year. Eligible drivers whose licenses expired in 1983 were subjects of the present study. Half of them were randomly assigned to a group whose members were sent offers of renewal by mail and the other half were sent standard renewal notices requiring appearance in a field office and successful completion of vision and traffic law tests. Traffic accidents and convictions following the mailout of these documents were tracked for both groups; results presented here cover a 4-year period subsequent to mailout. During this period (a normal license term in California), no significant overall difference was shown between the groups with respect to subsequent convictions or accidents. However, significant detrimental effects on accidents were noted for a subgroup of drivers who had experienced recent traffic violations or accidents which were not on their records at selection. Implications of these results are discussed.
Notes:
Provides evidence that waiving current vision test for one or two renewal cycles may not have much effect on accidents or convictions, although authors speculate that poorer accident performance in age group 30-50 may involve incipient vision problems not being detected. This study and others in this series had very large number of subjects (hundreds of thousands).
Author: Johnson, C.
Date: 1976.
Title: Effects of luminance and stimulus distance on accommodation and visual resolution.
Pub: Journal of the Optical Society of America, 66, 138-142.
Keywords:
Accommodation
Acuity
Dark focus
Spatial frequency
Static acuity
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Measurements of accommodation and visual resolution were obtained at a number of luminance levels and stimulus distances. With reductions in luminance the eye approached a "fixed-focus" condition of accommodation for intermediate distances, resulting in successively larger errors in accommodation for both near and far stimuli. The visual resolution values were initially affected by both the luminance and distance of the stimulus. Subsequent measurements of resolution, following the correction of accommodative errors, were found to be independent of the stimulus distance. The findings are discussed with regard to the problems of "night myopia" and variations in visual resolution with stimulus distance.
Notes:
Consistent with other work from Leibowitz lab on dark focus, night myopia.
Authors: Josephson, J. E., Erickson, P., Arthur, B., Holden, B., Harris, M., Tomlinson, A., Caffrey, B. E., Finnemore, V., & Silbert, J.
Date: 1990.
Title: Monovision.
Pub: Journal of the American Optometric Association, 61, (11), 820-826.
Keywords:
Acuity
Aging
Binocular/Monocular
Contrast sensitivity
Driving
Impairments
Low contrast acuity
Peripheral vision
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Monovision has been a controversial contact lens correction modality for over 30 years. This paper addresses the major issues and concerns and considers them in the light of patient safety, visual efficiency and practitioner liability.
Authors' Conclusion:
Information currently available indicates that monovision is an effective and reasonable prescription for correcting presbyopia, especially in the early period. Properly selected patients can expect to obtain good vision for most viewing distance under most circumstances. Patient selection criteria must include a full profile of ocular function, personal needs and regular activities. Patients should be fully informed of all correction alternatives, any visual limitations and how to exercise appropriate precautions. An informed consent document should be presented and explained to the patient and then signed.
"Clinical tests of binocular function, important in all patients, are critical in the fitting of monovision lenses. With properly exercised professional judgment and appropriate clinical screening, the safety and visual efficiency of the monovision corrected patient can be assured."
Notes:
Looks at advantages of monovision but concentrates on discussing possible disadvantages, impairments that might be created or exacerbated by monovision corrections. Notes possibility of increased glare sensitivity, effects on night driving, impairment of low contrast sensitivity, some other effects that are possible but not well documented.
Authors: Kelly, D. H.
Date: (1979).
Title: Motion and vision. II. Stabilized spatio-temporal threshold surface.
Pub: Journal of the Optical Society of America, 69, 1340-1349.
Keywords:
Acuity
Contrast sensitivity
Dynamic acuity
Flicker
Motion
Spatial frequency
Stabilized images
Static acuity
Velocity
Vision testing
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
The stabilized contrast-sensitivity function measured at a constant retinal velocity is tuned to a particular spatial frequency, which is inversely related to the velocity chosen. The Fourier transforms of these constant-velocity passbands have the same form as retinal receptive fields of various sizes. At low velocities, in the range of the natural drift motions of the eye, the stabilized contrast-sensitivity function matches the normal, unstabilized result. At higher velocities (corresponding to motions of objects in the environment), this curve maintains the same shape but shifts toward lower spatial frequencies. The constant-velocity passband is displaced across the spatio-temporal frequency domain in a manner that is almost symmetric about the constant-velocity plane at v=2 deg/s. Interpolating these diagonal profiles by a suitable analytic expression, we construct the spatio-temporal threshold surface for stabilized vision, and display its properties in terms of the usual frequency parameters; e.g., at low spatial frequencies, the temporal response becomes nearly independent of spatial frequency, while at low temporal frequencies, the spatial response becomes independent of temporal frequency.
Notes:
Concludes "our results suggest that retinal image motion is the sine qua non of vision." Looks at contrast sensitivity in combination with image motion, generated and measured in various ways. May be relevant if a contrast sensitivity test is to be included in CDL vision standard.
Authors: Kennedy, R. S., Ritter, A. D., Berbaum, D. S., & Hettinger, L. J.,
Date: 1987.
Title: Visual temporal acuities: model and prospectus for empirical study (report for contract number N62269-86-D-0109/0020).
Pub: Warminster, PA: Naval Air Development Center.
Keywords:
Acuity
Driving
Dynamic acuity
Event perception
Motion detection
Situational awareness
Velocity
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Temporal acuity refers to the ability to accurately and quickly perceive events as they occur serially over time. Generally, audition is considered to be the most temporally acute sensory modality, functioning primarily in the frequency domain; however, many military tasks place strong demands on visual temporal acuity. We argue that an insufficient understanding of temporal factors in vision may lead to inadequate design of military man-machine systems. For instance, the inability to rapidly "switch" attention from one visual display to another may be a major factor in the "human error" component. Military Standards currently contain specifications for visual display design which are relevant to static visual acuity, but contain no corresponding specifications which are relevant to temporal acuity.
The current paper proposes the predicate for a plan of study to be undertaken to identify the determiners, factors or sensory channels that underline visual temporal acuity. Specifically, a series of tests, based on prior empirical research on temporal factors in vision, have been implemented on a portable, lightweight computer. These tasks can be administered to individuals to determine: 1) the degree of their stability and reliability as psychometric indices of temporal acuity, 2) if stable and reliable, the number of temporal "factors" or channels, 3) their uniqueness relative to what is presently measurable and predictive of operational performance (i.e., intelligence and visual acuity), and 4) to determine the extent to which temporal acuity can be tested and modeled in a manner sufficiently parsimonious to permit implementation in Military Standard 1472c.
Notes:
Provides some rationale for using tests of "temporal" acuity, and for selection of particular tests. Tests are proposed for: critical flicker fusion, dynamic visual acuity, simultaneity, metacontrast, Neisser's visual search.
Author: Klein, R.
Date: 1991.
Title: Age-related eye disease, visual impairment, and driving in the elderly.
Pub: Human Factors 33 (5), pp. 521-525.
Keywords:
Acuity
Aging
Impairments
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract:
As people age, a number of visual functions such as acuity, visual field, and night vision deteriorate. This decline in vision is associated in part with an increase in vehicular accidents per mile driven by the elderly. Four age-related ocular conditions - cataract, macular degeneration, open-angle glaucoma, and diabetic retinopathy - are primarily responsible for the decline in visual acuity and visual field in the elderly. Few epidemiologic data are available about these diseases, and at present they cannot be prevented. There is need for more information about visual decline and how it affects driving performance and for development of pragmatic approaches for detecting and assessing the elderly driver with functional visual deficits.
Notes:
Review article: concentrates on four specific medical conditions. Issues addressed include vision testing, changes in signage and lighting design, possible driving restrictions. References to epidemiologic papers on eye disease.
Authors: Kline, D. W., Kline, T. J. B., Fozard, J. L., Kosnik, W., Schieber, F., & Sekuler, R.
Date: 1992.
Title: Vision, aging, and driving: The problems of older drivers.
Pub: Journal of Gerontology, 47(1) 27-34.
Keywords:
Acuity
Aging
Driving
Dynamic acuity
Event perception
Impairments
Low contrast acuity
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Although there are well-recognized declines in visual functioning with age, their contribution to the problems of older persons on tasks in the natural environment, including driving, are largely unknown. Adults ranging in age from 22-92 years were surveyed in regard to their visual difficulties when driving and performing everyday tasks. The visual problems of drivers increased with age along five different visual dimensions: unexpected vehicles, vehicle speed, dim displays, windshield problems, and sign reading. Several of the age-related visual problems that were reported appear to be related to the types of automobile accidents more common among older drivers. The study also replicated the findings from an earlier investigation of non-driving tasks that showed visual declines with age on five dimensions: visual processing speed, light sensitivity, dynamic vision, near vision and visual search. These findings indicate promising areas of research regarding the effects of visual aging on tasks in the natural environment.
Notes:
Survey study, using self-report only; no direct testing of visual functions. Findings are generally similar to other studies of vision and aging, but should be evaluated in light of other studies showing that self-evaluation of visual function and driving skills may not be well correlated with objectively tested visual function and driving skills.
Author: Kline, T .J. B., Ghali, L. M. , Kline, D. W., & Brown, S.
Date: 1990.
Title: Visibility distance of highway signs among young, middle-aged, and older observers; Icons are better than text.
Pub: Human Factors 32 (5), 609-619.
Keywords:
Acuity
Aging
Driving
Abstract:
The visibility distances for young, middle-aged, and elderly observers of four different highway signs were compared under day and dusk lighting conditions. No age differences were observed. Icon signs, however, were visible at much greater distances than were text signs for all three age groups, a difference that was more pronounced under dusk conditions. There were no age differences in the comprehension of icon signs, but there was considerable variability from one icon sign to another in the degree to which they were comprehended. Acuity was found to be a better predictor of the visibility distance of text signs in both day and dusk conditions than it was of icon signs. To the degree that they are comprehended, icon signs appear to offer drivers of all ages almost twice as much time in which to respond to them.
Notes:
Mean age of "middle-age" group was high (53+). Comprehension of icons is problematic.
Authors: Kruk, R. & Regan, D.
Date: 1983.
Title: Visual test results compared with flying performance in telemetry-tracked aircraft.
Pub: Aviation, Space, and Environmental Medicine, 54, 906-911.
Keywords:
Acuity
Contrast sensitivity
Dynamic acuity
Event perception
Motion detection
Pilot Performance
Velocity
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
We compared flying performance with the results of laboratory and airborne visual tests. Pilots flew high-performance, telemetry-tracked A4 and F-14 aircraft. In the low-level task, the index of performance was bombing accuracy; in air-to-air combat, performance was assessed by the number of missile hits scored per hit received (win/loss ratio). The chief laboratory tests comprised discrimination between two speeds of a radially-expanding flow pattern, and manual tracking of a visual target. Airborne tests comprised visual acquisition distance of an A4 aircraft, and visual sensitivity to a change in the course of an approaching A4 aircraft. We found that the flow pattern and movement-in-depth tracking test results correlated with bombing accuracy, confirming previously reported simulator findings. The results of airborne visual tests correlated with the win/loss ratio in combat, and tracking test results correlated with the number of missiles fired per combat engagement. Subsidiary test of motion, grating contrast, and visual acuity thresholds were carried out for comparability with other studies, but these measures did not predict flying performance.
Notes:
Same general comments as for Kruk, Regan, et al., 1981. This study found somewhat more compelling correlations between visual and flight performance measures. Note, contrast sensitivity was not predictive.
Authors: Kruk, R., Regan, D., Beverley, K. I., & Longridge, T.
Date: 1981.
Title: Correlations between visual test results and flying performance on the Advanced Simulator for Pilot Training (ASPT).
Pub: Aviation, Space, and Environmental Medicine, 52, 455-460.
Keywords:
Acuity
Contrast sensitivity
Dynamic acuity
Motion detection
Pilot performance
Spatial frequency
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Looking for visual differences in pilots to account for differences in flying performance, we tested five groups of subjects: Air Force primary student jet pilots, graduating (T38 aircraft) students, Air Force pilot instructors, and two control groups made up of experienced nonpilot aircrew and nonflying civilians. This interim report compares 13 different visual test results with low-visibility landing performance on the Air Force Human Resources Laboratory ASPT simulator. Performance was assessed by the number of crashes and by the distance of the aircraft from the runway threshold at the time of the first visual flight correction. Our main finding was that, for student pilots, landing performance correlated with tracking performance for a target that changed size (as if moving in depth) and also with tracking performance for a target that moved sideways. On the other hand, landing performance correlated comparatively weakly with psychophysical thresholds for motion and contrast. For student pilots, several of the visual tests gave results that correlated with flying grades in T37 and T38 jet aircraft. Tracking tests clearly distinguished between the nonflying group and all the flying groups. On the other hand, visual threshold tests did not distinguish between nonflying groups except for grating contrast, which distinguished between the nonflying group and the pilot instructors. The sideways motion tracking task was sensitive enough to distinguish between the various flying groups.
Notes:
Preliminary findings. Useful mostly as a suggestion of predictive validity for some kinds of vision testing, but flying differs from driving in important ways. This whole body of research is limited by using mostly pilots as subjects. These subjects have high acuity and low incidence of other visual deficits. Lack of between-subjects variability on vision measures restricts correlations between visual and other performance measures.
Authors: Leibowitz, H. & Owens, D. A.
Date: 1978.
Title: New evidence for the intermediate position of relaxed accommodation.
Pub: Documenta Ophthalmologica, 46 (1), 133-147.
Keywords:
Accommodation
Acuity
Dark focus
Driving
Low contrast acuity
Holding: Full text ( X) Abstract/Summary ( )
Abstract:
Experimental evidence is presented that the focus of the eye tends to return passively to an individually characteristic intermediate resting position or dark-focus whenever (1) the stimulus to accommodation is degraded or (2) when the quality of the image is independent of focus. Based on measurements of the dark-focus with a laser optometer, it is possible to predict the magnitude of night, empty field, and instrument myopia on an individual basis. The role of the intermediate dark-focus as a factor in accommodation also provides an explanation for the paradoxical variation of visual acuity with observation distance. Applications to night myopia and night driving are described, and implications for clinical practice are discussed.
Authors: Leibowitz, H. W. & Owens, D. A.
Date: 1975.
Title: Anomalous myopias and the intermediate dark focus of accommodation.
Pub: Science, 189, 646-648.
Keywords:
Acuity
Accommodation
Dark focus
Low contrast acuity
Static acuity
Vision testing
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
The dark focus of accommodation for an individual observer correlates highly with the magnitude of night, empty field, and instrument myopia. These anomalous myopias are interpreted as resulting from the passive return of accommodation to an individually determined intermediate dark focus when the stimulus for accommodation is degraded or absent, or when the need for accommodation is eliminated.
Authors: Leibowitz, H. W., Owens, D. A., & Helmreich, R. L.
Date: 1995.
Title: Research needs in transportation: from highways to airways.
Pub: Emerging Needs and Opportunities for Human Factors Research, Part II, Chapter 9, Page 1. (In Press)
Keywords:
Acuity
Aging
Binocular/Monocular
Contrast sensitivity
Driving
Dynamic acuity
Event perception
Foveal vision
Impairments
Low contrast acuity
Motion detection
Peripheral vision
Situational awareness
Spatial frequency
Standards
Static acuity
Useful field of view
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract:
This chapter discusses needs for behavioral research in transportation focusing on two diverse areas that are representative of the broad scope of human factors. One area, vehicular traffic safety, draws on traditional concerns with the individual and the machine, while the second, aviation safety, centers on team performance and training in a high technology environment. With regard to aviation, the definition of relevant human factors research includes components of organizational, social and personality, educational, and cross-cultural psychology, as well as more traditional cognitive, experimental, and engineering concerns.
All forms of modern transportation--aviation, maritime, rail, space, and vehicular--involve the interaction of individuals or groups with technology in a regulated system. The successful application of human factors research must reflect an understanding of systems influences on behavior and on the acceptance of solutions. Despite its concentration on the automobile and one aspect of aviation, many of the research needs discussed apply equally to other forms of transportation, such as railroad and maritime operations.
Authors: Leibowitz, H., & Post, R.
Date: 1982.
Title: The two modes of processing concept and some implications.
Pub: In Beck, J. (Ed.), Organization and Representation in Perception. Hillsdale, NJ: Lawrence Erlbaum Associates. pp. 343-363.
Keywords:
Ambient vs. focal
Driving
Holding: Full text (X) Abstract/Summary ( )
Abstract: Author's Introduction (truncated)
The first hundred years in the history of modern psychology have resulted in the development of a number of theories. In particular, the study of perception has been enriched by theoretical formulations, such as those of the Gestalt psychologists and of J. J. Gibson, which have played such an important role in the conference. More recently, we have been introduced to sophisticated information processing models and to the spatial frequency analysis of visual scenes.
There are many advantages to theoretical points of view. One advantage is to suggest new and different ways to look at phenomena. Even though the scope of a given theory may be limited, it suggests new "mental sets" and unique ways of approaching interesting observations.
The purpose of the present paper is to discuss a recent theoretical position that has stimulated novel analyses and interpretations of surprisingly diverse findings. The "two-visual systems" concept of concern here originated with Gerald Schneider's dissertation at M.I.T. in the early 1960s in which he discovered that object recognition and spatial orientation can be selectively impaired in the hamster by lesions of the cortex or the superior colliculus. In 1967 Schneider, along with Richard Held, Colwyn Trevarthen, and David Ingle, presented a symposium at the Eastern Psychological Association meeting where they described experiments, including studies on humans, which they interpreted in terms of the two systems concept (Held, 1968; Ingle, 1967; Schneider, 1967; Trevarthen, 1968). For anyone interested in the history and early development of this problem, these works represent a prime literature source.
Although the concept of two systems is derived from selective ablation studies and much of the literature has a strong anatomical flavor, the present treatment deliberately de-emphasizes anatomy. This is of course not meant to minimize the ultimate importance of neurophysiology, however. Because the nervous system is much more complex in humans than in the hamster and our concern is primarily with perception and behavior in humans, it seems appropriate to follow Held's suggestion and to speak of "two modes of processing spatially distributed information" (Held, 1970).
The two modes of processing concept can best be described in functional terms. It posits two independent and dissociable modes of processing: (1) a "focal" mode that is in general concerned with the question of "what" and subserves object recognition and identification; (2) an "ambient" mode concerned with the question of "where" which mediates spatial orientation, locomotion, and posture.
In the original formulation of the two systems or modes of processing, reference was made to two visual systems, but this must be modified. Although visual information is adequate for the focal mode, the ambient mode involves the coordination of motor activity with the visual, vestibular, auditory and somatosensory system, particularly, kinesthesis. In the discussion that follows, examples of the diverse basis of the ambient mode and the importance of interaction among its various components are described. . .
Notes:
Longer exposition of one portion of material in Leibowitz, Post, Brandt, & Dichgans, 1980.
Stress on interactions with modalities other than visual.
Authors: Leibowitz, H., Post, R., Brandt, T., and Dichgans, J.
Date: 1980.
Title: Implications in recent developments in dynamic spatial orientation and visual resolution for vehicle guidance.
Pub: In Wertheim, A., Wagenaar, W. A., and , H. (Eds.), Tutorials on Motion Perception. pp. 231-260. New York/London: Plenum Press.
Keywords:
Acuity
Aging
Contrast sensitivity
Dark focus
Driving
Dynamic acuity
Event perception
Low contrast acuity
Motion detection
Peripheral vision
Situational awareness
Spatial frequency
Vision testing
Visual field
Holding: Full text (X) Abstract/Summary ( )
Abstract: (Authors' Introduction)
The objective of the present chapter is to examine a number of problems of vehicle guidance within the context of recent developments in psychophysics, neurophysiology, anatomy and neurology. The theme of this presentation is that these, like other applied problems, exist primarily when the underlying physiological mechanisms are not well understood. With an increased understanding of fundamentals we can not only better appreciate the nature of applied problems but can also frequently identify methods towards their solution. In turn, applied problems serve a valuable function by directing attention to gaps in our basic understanding which leads to suggestions for fruitful areas for research. At the same time as we learn more about fundamentals, new application possibilities manifest themselves.
The plan of the present chapter is to review selectively three areas in which recent research has increased our understanding of fundamental mechanisms. These are 1) the two modes of processing concept; 2) the multisensory nature of spatial orientation; and 3) the intermediate dark-focus of accommodation. Space does not permit an exhaustive treatment of these topics. Rather, the literature will be reviewed briefly in order to provide a basis for describing the relevance of these developments to specific problems in vehicle guidance and locomotion. By juxtaposing basic developments and potential applications their close relationships should be apparent, and the value of an approach which purposely de-emphasizes differences between "basic" and "applied" science will, it is hoped, be demonstrated.
Notes:
Much useful information, and the authors make explicit connections between visual functions and driving. Rationale given for testing various visual functions for driver licensure.
Author: Lempert, P.
Date: ??
Title: Standards for contrast acuity/sensitivity and glare testing.
Pub: [GET PUB FROM PSYCHLIT] pp. 113-119
Keywords:
Acuity
Central vision
Contrast sensitivity
Glare
Low contrast acuity
Spatial frequency
Standards
Static acuity
Vision testing
Holding: Full text (X) Abstract/Summary ( ) Reference only ( ) Other ( )
Abstract: (Study Team Abstract)
Differences in display area, luminance, test object design, statistical validation procedures, and contrast often generate inconsistent and/or contradictory test results. Therefore, the author suggests that there is an immediate need for general agreement on the critical design criteria of these devices and on uniform test procedures. Lempert briefly discusses NAS/NRC standards for the assessment of visual acuity, which specify test parameters. He asserts that the background luminance must remain constant at all levels of contrast for contrast acuity/sensitivity testing. In normal eyes, at high luminance, the peak sensitivity is about 5 cycles per degree, and high-frequency cutoff occurs at approximately 60 cpd. Contrast is sometimes defined as the maximum deviation from the background luminance divided by the background luminance. While this definition is usually applied to eye charts, a difficulty with this format is that the mean luminance decreases with optotypes that occupy a large proportion of the total screen. Accordingly, Lempert presents a definition of contrast in which contrast is regarded as modulation, the ratio of the maximum change in luminance from its mean value.
Dynamic optotype presentations can help detect degradation or retinal summation mechanisms, which is useful in selection of candidates for complex visual tasks. Lempert asserts that modern standards must include criteria for dynamic testing. In addition, Lempert suggests that an inadequate number of targets, such as a letter chart using only three letters at each contrast or with only one optotype of each size and contrast, seriously undermines test validity. Finally, the author states that the recommendations of the Committee on Vision for the Assessment of Distance Visual Acuity and the Committee's observations on contrast testing should be the basis for new clinical contrast acuity/sensitivity systems.
Author: Lippmann, O.
Date: 1979.
Title: The effect of the Texas Medical Advisory Board for driver licensing on driving performance.
Pub: Proceedings of the 23rd Annual Conference, American Association for Automotive Medicine, in cooperation with the University of Louisville School of Medicine, pp. 203-210.
Keywords:
Aging
Driving
Impairments
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
Traffic offenses related to chronic medical conditions and the effect of a Medical Advisory Board for Driver Licensing are discussed.
The accident and violation ratio of 19,110 Texas drivers with medical limitations was studied. Ratios before and after Board review were compared in each category of illness and in each age group and related to the state average.
The effect was good in all categories of illness with the exception of limitations related to psychiatric and addiction disorders. The accident ratio of all drivers with chronic medical conditions improved by 51%. Traffic violations improved by 21%.
Other variables in the determination of the effect of the Board were discussed.
A substantial improvement of the statewide traffic safety may be attributed to the effect of the Medical Advisory Board.
Notes:
Medical model; Board review most beneficial for drivers over 40 yrs old, extremely beneficial for drivers with vision problems.
Authors: Long, G. M., & Garvey, P. M.
Date: 1988.
Title: The effects of target wavelength on dynamic visual acuity under photopic and scotopic viewing
Pub: Human Factors, 30 (1), 3-13.
Keywords:
Acuity
Color vision
Dynamic acuity
Foveal vision
Low contrast acuity
Vision testing
Holding: Full text (X) Abstract/Summary ( )
Abstract:
The effects of target wavelength on the resolution of moving targets were investigated over a range of target velocities under both photopic and scotopic viewing conditions. The wavelength of the photopically matched targets had no effect on dynamic acuity under the bright background condition. However, with low background luminance the wavelength of the targets had pronounced effects, with blue targets producing far superior resolution and red targets, the poorest resolution. These results were maintained over both 250- and 400-ms target durations and regardless of whether initial target position was foveal or peripheral. The likely contribution of the rod system to dynamic visual acuity under some conditions is proposed, and possible implications for applied settings are discussed.
Authors: Long, G. M., & Riggs, C.
Date: 1991.
Title: Training effects on dynamic visual acuity with free-head viewing.
Pub: Perception, 20, 363-371.
Keywords:
Dynamic acuity
Static acuity
Holding: Full text ( x ) Abstract/Summary ( )
Abstract:
Training effects on dynamic visual acuity (DVA) were determined over a range of target durations and target velocities under the viewing conditions of free-head movement. Dynamic acuity levels were lower than static acuity levels, and training was found to be very effective in improving performance, particularly under the most difficult conditions in which performance was poorest. Improvement was also most evident among those observers who initially exhibited the poorest DVA scores. Preliminary comparisons between DVA scores of a non-select sample of college students and those of a small group of college athletes indicated that the athletes were not very different from the nonselect group and would also benefit from training on the task.
Notes:
Authors raise many interesting questions about training effects: relation to real-world visual tasks, duration of training effect, etc. These are relevant to CMV driver licensing issues.
Authors: Lovsund, P., Hedin, A., & Tornros, J.
Date: 1991.
Title: Effects on driving performance of visual field defects: A drivin