Experiments have verified the observations of Corbett and White that people are more sensitive to flicker on raster-scanned displays (e.g., television and visual display terminals) if the field scan direction is changed from the conventional top-to-bottom direction to bottom to top, left to right, or right to left. When measured by means of the flicker fusion frequency (FFF), this effect is present only when normal eye movements are permitted. With fixation, the FFF is similar for all scan directions. The effect is demonstrated by the different frequencies at which a directional component is detected in the flicker (which we have called the rolling flicker threshold frequency, or RFTF); the RFTF is lower for top-to-bottom scanning. The effect does not appear to be associated with any asymmetry in eye movements or with eccentricity of the retinal image. The hypothesis that this difference is a consequence of adaptation to televisions and VDTs is supported by the observation that the effect's magnitude correlates with daily exposure time to televisions and VDTs and by a pilot study showing that the effect is reduced when one views a television scanned from bottom to top for 1 h.
Get full access to this article
View all access options for this article.
References
1.
Addams, R. (1834) An account of a peculiar optical phenomenon seen after looking at a moving body. London and Edinburgh Philosophical Magazine and Journal of Science (3rd series), 5, 373–374.
2.
Bauer, D., Bonacker, M., & Cavonius, C. (1983). Frame repetition rate for flicker-free viewing of bright VDU screens. Displays--Technology and Applications, 4(1) 31–33.
3.
Becker, W., & Jurgens, R. (1990) Human oblique saccades: Quantitative analysis of the relation between horizontal and vertical components. Vision Research, 30, 839–920.
4.
Brooks, B. A., & Fuchs, A. F. (1975) Influence of stimulus parameters on visual sensitivity during saccadic eye movements. Vision Research, 15, 1389–1398.
5.
Brooks, B. A., Yates, J. T., & Coleman, R. D. (1980) Perception of objects moving at saccadic velocities during saccades and during fixation. Experimental Brain Research, 40, 71–78.
6.
Cakir, A., Hart, D. J., & Stewart, T. F. M. (1979). Visual display terminals: A manual covering ergonomics, workplace design, health and safety, task organization.New York: Wiley.
7.
Campbell, F. W., & Durden, K. (1983). The visual display terminal issue: A consideration of its physiological, psychological and clinical background. Ophthalmic and Physiological Optics, 3, 167.
8.
Chaplin, R., & Freemantle, R. A. (1987). Measurement of perceived flicker in VDU products. Displays-Technology and Applications, 8(1) 22–28.
9.
Collewijn, H., Erkelens, C. J., & Steinman, R. M. (1988). Binocular co-ordination of human vertical saccadic eye movements. Journal of Physiology [London], 404, 183–197.
10.
Corbett, J. M., & White, T. A. (1976) Visibility of flicker in television pictures. Nature, 261, 689–690.
11.
Cynader, M., Berman, N., & Hein, A. (1975) Cats raised in a one directional world: Effects on receptive fields in visual cortex and superior colliculus. Experimental Brain Research, 22, 267–280.
12.
Dain, S. J., McCarthy, A. K., & Chan-Ling, T. (1988). Symptoms in VDU operators. American Journal of Optometry and Physiological Optics, 65(3) 162–167.
13.
Dainoff, M. J. (1982). Occupational stress factors in VDT operation: A review of empirical research. Behaviour and Information Technology, 1(2) 141–176.
14.
Daw, N. W., & Wyatt, H. J. (1976). Raising rabbits in a unidirectional environment: An attempt to modify directional selectivity in the retina. Journal of Physiology [London], 240, 309–330.
15.
DeGroot, J. P., & Kamphuis, A. (1983) Eyestrain in VDU users: Physical correlates and long term effects. Human Factors, 25, 409–413.
16.
Dill, A. B., & Gould, J. D. (1970) Flickerless regeneration rates for CRT displays as a function of scan order and phosphor persistence. Human Factors, 12, 465–471.
17.
Engstrom, E. W. (1935). A study of television image characteristics. Proceedings of the Institute of Radio Engineers, 23(4), 295–310.
18.
Foster, D. H. (1970a) The response of the human visual system to moving spatially-periodic patterns: Further analysis. Vision Research, 11, 57–81.
19.
Foster, D. H. (1970b). Some experiments on the detection of motion by the human visual system and their theoretical interpretation. Unpublished Ph.D. thesis, University of London.
20.
Foster, D. H. (1971) A model of the human visual system in its response to certain classes of moving stimuli. Kybernetik, 8, 69–84.
21.
Goldstein, A. G. (1957) Judgments of visual velocity as a function of length of observation time. Journal of Experimental Psychology, 54, 457–461.
22.
Gorea, A. (1978) Directional and non-directional coding of a spatio-temporal modulated stimulus. Vision Research, 19, 545–549.
23.
Grandjean, E. (1987). Ergonomics in computerized offices.London: Taylor & Francis.
24.
Harris, C. S. (1980). Insight or out of sight? Two examples of perceptual plasticity in the human adult. In C. S. Harris (Ed.), Visual coding and adaptability (pp. 95–149). Hillsdale, NJ: Erlbaum.
25.
Helander, M. G., Billingsley, P. A., & Schurik, J. M. (1984). An evaluation of human factors research on VDTs in the workplace. In F. A. Muckler (Ed.), Human factors review (pp. 55–129). Santa Monica. CA: Human Factors and Ergonomics Society.
26.
Howarth, P. A., & Istance, H. O. (1985). The association between visual discomfort and the use of visual display units. Behaviour and Information Technology, 4(2), 131–149.
27.
Hubel, D. H., & Wiesel, T. N. (1962) Receptive fields, binocular interaction and functional architecture in the cat's visual cortex. Journal of Physiology, 160, 106–154.
28.
Kalfin, K., & Locke, S. (1971). Evaluation of long term visual motion afterimage following monocular stimulation. Vision Research, 12, 359–361.
29.
Kennedy, A., & Murray, W. S. (1993). Flicker on VDU screens. Nature, 365(6443), 213.
30.
Läubli, T., & Grandjean, E. (1984). The magic of control groups in VDT field studies. In E. Grandjean (Ed.), Ergonomics and health in modern offices (pp. 112–129). London: Taylor & Francis.
31.
Le Grand, Y. (1968). Light, color and vision.London: Chapman & Hall.
32.
Levinson, E., & Sekuler, R. (1976) Adaptation alters perceived direction of motion. Vision Research, 16, 779–781.
33.
McCollough, C. (1965) Color adaptation of edge detectors in the human visual system. Science, 149, 1115–1116.
34.
Mourant, R. R., Lakshmanan, R., & Chantadisai, R. (1981) Visual fatigue and cathode ray tube display terminals. Human Factors, 23, 529–540.
35.
Moussaoui, N., & Freivalds, A. (1986). Comparison of eye movements while reading hard copy print and text on visual display terminals. In W. Karwowski (Ed.), Trends in ergonomics/human factors 111 (pp. 267–275). Amsterdam: Elsevier.
36.
Nylén, P. (1985) A light phenomenon perceived when viewing CRT-based VDT screens with positive image. Applied Ergonomics, 16, 82–87.
37.
Oohira, A., Goto, K., & Ozawa, T. (1983) Vertical and oblique saccadic eye movements. Japanese Journal of Ophthalmology, 27, 631–646.
38.
Östberg, O., Shahnavaz, R., & Stenberg, R. (1987). CRT flicker and scan-line direction. Displays--Technology and Applications, 8(2), 75–78.
39.
Sekuler, R., & Ganz, L. (1963) Aftereffect of seen motion with a stabilized retinal image. Science, 139, 419–420.
40.
Sperling, G. (1971). Flicker in computer-generated visual displays: Selecting a CRO phosphor and other problems. Behavioural Research Methods and Instrumentation, 3(3), 151–153.
41.
Stromeyer, C. F. (1978). Form-color aftereffects in human vision. In R. Held, H. Leibowitz, & H. L. Teuber (Eds.), Handbook of sensory physiology: Vol. VIII. Perception (pp. 97–142). New York: Springer-Verlag.
42.
Thomson, W. D. (1985). Flicker on raster scanned displays as a function of field scan direction. Unpublished Ph.D. thesis, City University, London.
43.
Turnage, R. E. (1966, May/June). The perception of flicker in cathode ray tube displays. Information Display, 38–52.
44.
van der Zee, E., & van der Meulen A. W. (1982) The influence of field repetition frequency on the visibility of flicker on displays. Institute for Perception Research, Annual Progress Report, 17, 76–83.
45.
van Nes, F. L., Koenderink, J. J., & Bouman, M. A. (1967) Spatio-temporal modulation transfer in the human eye. Journal of the Optical Society of America, 57, 1082–1088.
46.
Volkmann, F. C., Riggs, L. A., & Moore, R. K. (1978). Central and peripheral determinants of saccadic suppression: A brief review. In J. W. Senders, D. F. Fisher, & R. A. Monty (Eds.), Eye movements and the higher psychological functions (pp. 35–54). Hillsdale, NJ: Erlbaum.
47.
Volkmann, F. C., Schick, A. M. L., & Riggs, L. A. (1967) Time course of visual inhibition during voluntary saccades. Journal of the Optical Society of America, 58, 562–569.
48.
West, D. C., & Boyce, P. R. (1968) The effect of flicker on eye movements. Vision Research, 8, 171–192.
49.
Wilkins, A. (1986) Intermittent illumination from visual display units and fluorescent lighting affects movements of the eyes across text. Human Factors, 28, 75–81.
50.
Wurtz, R. H. (1969) Comparison of effects of eye movements and stimulus movements on striate cortex neurons of the monkey. Journal of Neurophysiology, 32, 987–994.
51.
Yee, R. D., Schiller, V. L., Lim, V., Baloh, F. G., Baloh, R. W., & Honrubia, V. (1985). Velocities of vertical saccades with different eye movement recording methods. Investigative Ophthalmology and Visual Science, 26, 938–945
