Observer's control of the moving stimulus increases the flash-lag effect

Vision Res. 2009 Sep;49(19):2363-70. doi: 10.1016/j.visres.2009.06.023. Epub 2009 Jul 22.

Abstract

The flash-lag effect (FLE) consists in perceiving a briefly presented stationary stimulus to lag behind an aligned moving stimulus. This study investigates the effects of actively controlling the moving stimulus. By means of a robotic arm, observers continuously moved a dot along a circular trajectory, and a flash was displayed closely at unpredictable times. In two experiments, we found that the FLE was larger when participants controlled the moving stimulus, compared to a computer-controlled condition. Two control conditions tested the possibility that the observed modulation of the FLE was due to visuo-spatial attention or dual-task factors. This study provides evidence that the motor system interacts with and possibly speeds up the processing of a moving visual stimulus when the observer controls its movement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Female
  • Humans
  • Male
  • Middle Aged
  • Motion Perception / physiology*
  • Optical Illusions / physiology*
  • Photic Stimulation / methods
  • Psychomotor Performance / physiology*
  • Reaction Time / physiology
  • Robotics
  • User-Computer Interface
  • Young Adult