Flash lag illusion

The flash-lag effect. When a visual stimulus moves along a continuous trajectory, it may be seen ahead of its veridical position with respect to an unpredictable event such as a punctuate flash. This illusion tells us something important about the visual system: contrary to classical computers, neural activity travels at a relatively slow speed. It is largely accepted that the resulting delays cause this perceived spatial lag of the flash. Still, after several decades of debates, there is no consensus regarding the underlying mechanisms.
The still photo showing the green flash (frame 073, black background omitted).

The flash lag illusion or flash-lag effect is a visual illusion wherein a flash and a moving object that appear in the same location are perceived to be displaced from one another.[1][2] Several explanations for this simple illusion have been explored in the neuroscience literature (for a review, see[3]).

  1. ^ MacKay, D. M. (15 February 1958). "Perceptual Stability of a Stroboscopically Lit Visual Field containing Self-Luminous Objects". Nature. 181 (4607): 507–508. Bibcode:1958Natur.181..507M. doi:10.1038/181507a0. PMID 13517199. S2CID 4241312.
  2. ^ Nijhawan, Romi (28 July 1994). "Motion extrapolation in catching". Nature. 370 (6487): 256–257. Bibcode:1994Natur.370..256N. doi:10.1038/370256b0. PMID 8035873. S2CID 12605353.
  3. ^ Kanai, Ryota; Sheth, Bhavin R; Shimojo, Shinsuke (October 2004). "Stopping the motion and sleuthing the flash-lag effect: spatial uncertainty is the key to perceptual mislocalization". Vision Research. 44 (22): 2605–2619. doi:10.1016/j.visres.2003.10.028. PMID 15358076.