| Title | The spiral aftereffect : III, Some effects of perceived size, retinal size, and retinal speed on the duration of illusory motion. |
|---|---|
| Record ID | 39165 |
| Personal Name Creator |
Mehling, Kevin D.; Collins, William E.; Schroeder, David J. |
| Corporate Creator | Civil Aeromedical Institute |
| Corporate Contributor |
United States. Office of Aviation Medicine |
| Publisher | Civil Aerospace Medical Institute |
| Publication Date | 19710700 |
| Language | English |
| Abstract | Many safety problems encountered in aviation have been attributed to visual illusions. One of the various types of visual illusions, that of apparent motion, includes as an aftereffect the apparent reversed motion of an object after it ceases real movement. The study examined some effects of perceived size, perceived distance, and perceived stimulus speed on the persistence of illusory motion in the spiral aftereffect. Two major conditions were used: Size Constant: a 4-inch spiral was positioned to subtend visual angles of 1/2, 1, 2, 4, and 8 deg with seven rates of retinal speed (10-100 minarcs/sec) used at each angle; Angle Constant: three sizes of spirals were positioned so that each subtended visual angles of 2, 4, and 8 deg with physical speed held constant (75 rpm) in one case, and retinal speed (45 minarcs/sec) held constant in another. Durations of the illusion were significantly affected by low retinal speeds, by small visual angles, and by perceived size per unit of retinal size. The results suggest that complex interactions of physical and perceptual factors can significantly alter the presence and the magnitudes of visual illusions of motion. |
| Rosap ID | dot:20968 |
| Rosap URL | https://rosap.ntl.bts.gov/view/dot/20968 |
| TRT Terms | Motion; Perception; Motion perception; Visual perception; Distance perception; Depth perception; Velocity perception; Optical properties; Size; Depth; Vision; Eye location; Eye fixations; Eye movements; Motor skills; Motor reactions; Reaction time; Human subject testing; Statistics; Air pilots; Aircraft; Experiments; Hypothesis testing; Ratios; Mathematical prediction |
| General Subjects | Optical illusions; Perception; Distraction (Psychology); Stimulus satiation; Visual perception; Depth perception; Motion perception (Vision); Vision; Eye--Examination; Eye--Movements; Motor ability; Reaction time; Human beings--Testing; Airplanes; Pilots and pilotage; Statistical hypothesis testing; Ratio analysis; Prediction (Logic) |
| Classification | NTL - AVIATION - AVIATION; NTL - AVIATION - Aviation Human Factors; NTL - REFERENCES AND DIRECTORIES - Statistics |
| Geographical Coverage |
United States |
| Report Number | FAA-AM-71-31; DOT/FAA/AM-71/31 |
| Resource type | Tech Report |
| URL | https://ntlrepository.blob.core.windows.net/lib/39000/39100/39165/AM71-31.pdf |
| Format | |
| Database | NTL Digital Repository |