Search research articles

Search research articles

Related Experiment Videos

The flash-lag effect during illusory chopstick rotation.

Stuart Anstis¹

¹Department of Psychology, University of California, San Diego (UCSD), 9500 Gilman Drive, La Jolla, CA 92093-0109, USA. sanstis@ucsd.edu

|September 12, 2007

Summary

This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

The bookend effect.

i-Perception·2026

Same author

Me and my shadow: Elongated sunset shadows disrupt size constancy.

i-Perception·2026

Same author

Ambiguous apparent motion in exchanging disks.

i-Perception·2025

Same author

Perceptual grouping and the bounce-stream illusion.

i-Perception·2025

Same author

Illusory shrinkage of objects under backward masking.

i-Perception·2024

Same author

Pink illusions and white shifts.

i-Perception·2024

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

The flash-lag effect, where a flashed object appears to lag moving objects, was studied using a visual illusion. Findings suggest this perceptual phenomenon occurs early in the visual system before motion is fully processed.

Area of Science:

Visual perception
Neuroscience
Psychophysics

Background:

The flash-lag effect describes a static stimulus appearing to lag behind a moving stimulus.
Previous research suggests the flash-lag effect is related to motion processing in the visual system.

Purpose of the Study:

To investigate the early visual system mechanisms underlying the flash-lag effect.
To determine if the flash-lag effect occurs before or after motion signals are parsed.

Main Methods:

Utilized the 'chopstick illusion' where a flash was presented near a counter-rotating object.
The object's actual counterclockwise motion was perceived as clockwise due to the illusion.
Observed the perceived position of the flashed object relative to the moving object.

Related Experiment Videos

Main Results:

The flash was perceived as displaced in the direction of the apparent (clockwise) motion.
This perceived displacement aligned with the physical, not the subjective, direction of rotation.
The results indicate a dissociation between physical motion and perceived motion direction.

Conclusions:

The flash-lag illusion likely originates in early visual processing stages.
It occurs before the visual system fully interprets motion signals and object trajectories.
This suggests a fundamental aspect of how the brain constructs visual reality from sensory input.