Events before the flash Do influence the flash-lag magnitude.
The flash-lag effect occurs when a flash abreast of a smoothly moving object is perceived to spatially lag the moving object. The postdiction accounts of this effect assume either that the flash "resets" motion detectors [Science 287 (2000) 2036], or that position information is not computed for moving objects until it is needed [Trends in the Neurosciences 25 (2002) 293], the latter view having also been proposed by Brenner and Smeets [Vision Research 40 (2000) 1645]. According to these accounts, events occurring before the flash should not change the magnitude of the flash-lag effect. In our experiment, pre-exposure of the moving object as a stationary stimulus, for as little as 50 ms before the flash occurred, significantly reduced the flash-lag effect.
Chappell
Mark
M
School of Applied Psychology, Griffith University, Nathan, Queensland 4111, Australia. m.chappell@griffith.edu.au
Hine
Trevor J
TJ
D003463:Cues; D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D009903:Optical Illusions; D010775:Photic Stimulation; D011601:Psychophysics; D013997:Time Factors