The Far-Anchor Effect: Errors in the Perception of Motion and Implications for Aviation Safety

Abstract

The far-anchor effect is responsible for a motion-in-depth illusion that has only recently been recognized. When viewing conditions are limited, motions in depth of a farther target in a two-object display may readily be perceived as opposite motions in depth of the nearer target. The present studies determined whether this error could be avoided through controlled fixation or training with feedback. Under conditions of reduced visibility, participants (college students) viewed 64 two-target presentations varying in the position of the moving target and its direction of motion. Neither fixation instructions nor informational feedback about motion errors affected the occurrence of the basic illusion, nor did a vertical separation of the targets eliminate the main effect, indicating the robustness of the motion illusion under some relatively realistic variations. Such errors in judging motion in depth have significance for both midair collisions between aircraft and ground-incursion accidents under conditions of reduced visibility. Potential applications include the elaboration of examples used in pilot training programs or in training programs for ground personnel.

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References

Aviation Safety: Hearings before the Subcommittee on Department of Transportation and Related Agencies of the House Committee on Appropriations, 106th Cong., 2d Sess., 45 (2000) (testimony of Jim Hall).

Clarke, D. L. (1998). Errors in the perception of motion in depth: Effects of a structured field-of-view. Unpublished doctoral dissertation, North Carolina State University, Raleigh.

Epstein, W. (1977). What are the prospects for a higher-order stimulus theory of perception? Scandinavian Journal of Psychology, 18, 164–171.

Foley, J. (1985). Binocular distance perception: Egocentric distance tasks. Journal of Experimental Psychology: Human Perception and Performance, 11, 133–149.

Gogel, W. C. (1969). The sensing of retinal size. Vision Research, 9, 1079–1094.

Gogel, W. C. (1972). Scalar perceptions with binocular cues of distance. American Journal of Psychology, 85, 477–497.

Gogel, W. C. (1979). The common occurrence of errors of perceived distance. Perception & Psychophysics, 25, 2–11.

Gogel, W. C. (1990). A theory of phenomenal geometry and its applications. Perception & Psychophysics, 48, 105–123.

Gogel, W. C. , & Griffin, B. W. (1982). Spatial induction of illusory motion. Perception, 11, 187–199.

10.

Gogel, W. C. , & Tietz, J. D. (1977). Eye fixation and attention as modifiers of perceived distance. Perceptual and Motor Skills, 45, 343–362.

11.

Mayer, C. M. (1998). Effects of noise and organizational factors on the perception of motion in depth. Unpublished master's thesis, North Carolina State University, Raleigh.

12.

Mershon, D. H. (1997). Phenomenal geometry and the measurement of perceived auditory distance. In R. H. Gilkey & T. R. Anderson (Eds.), Binaural and spatial hearing in real and virtual environments (pp. 257–274). Mahwah, NJ: Erlbaum.

13.

Mershon, D. H. , Granberry-Hager, S. , Bartlett, K. , & DeCamp, B. (1981). Scalar perceptions of distance in a multiobject binocular display. Bulletin of the Psychonomic Society, 18, 249–252.

14.

Mershon, D. H. , Jones, T. A. , & Taylor, M. E. (1993). Organizational factors and the perception of motion in depth. Perception & Psychophysics, 54, 240–249.

15.

Mershon, D. H. , & Lembo, V. L. (1977). Scalar perceptions of distance in simple binocular configurations. American Journal of Psychology, 90, 17–28.

16.

Mershon, D. H. , Voncannon, M. G. , & Windes, W. R. (1976). Scalar perceptions of distance for a monocularly determined depth interval. Bulletin of the Psychonomic Society, 8, 341–342.

17.

Niall, K. K. , Reising, J. D. , & Martin, E. L. (1999). Distance estimation with night vision goggles: A little feedback goes a long way. Human Factors, 41, 495–506.

18.

O'Hare, D. , & Roscoe, S. (1990). Flightdeck performance: The human factor. Ames: Iowa State University Press.

19.

Oster, C. V. , Strong, J. S. , & Zorn, C. K. (1992). Why airplanes crash: Aviation safety in a changing world. New York: Oxford University Press.

20.

Rock, I. , Auster, M. , Schiffman, M. , & Wheeler, D. (1980). Induced movement based on subtraction of motion from the inducing object. Journal of Experimental Psychology: Human Perception and Performance, 6, 391–403.