Search research articles

Search research articles

Related Experiment Videos

Delboeuf illusion study.

Tadas Surkys¹, Algis Bertulis, Aleksandr Bulatov

¹Department of Biology, Kaunas University of Medicine, Lithuania. surkys@vision.kmu.lt

Medicina (Kaunas, Lithuania)

|September 12, 2006

Summary

The Delboeuf illusion

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

Filled space and filled time illusions vary similarly with analogous stimulus parameters.

Scientific reports·2025

Same author

Expansion of perceived size of visual stimuli: Objects look wider than equivalent empty spaces.

Perception·2025

Same author

Effects of repeated stimulus presentations on Oppel-Kundt and Müller-Lyer illusions.

Vision research·2025

Same author

Combined manifestation of two geometric visual illusions.

Attention, perception & psychophysics·2024

Same author

Effects of normalized summation in the visual illusion of extent.

Attention, perception & psychophysics·2023

Same author

Changes in length judgments caused by rotation of the contextual distractor.

Attention, perception & psychophysics·2022

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

Area of Science:

Psychophysics
Visual Perception
Neuroscience

Background:

The Delboeuf illusion is a well-known visual illusion where the perceived size of a central circle is influenced by the size of an surrounding ring.
Understanding the factors influencing this illusion is crucial for visual science and applied fields like display technology.

Purpose of the Study:

To systematically investigate how spatial parameters of stimulus patterns affect the magnitude of the Delboeuf illusion.
To explore the impact of stimulus shape, size, luminance, and surround dimensions on perceived size.

Main Methods:

Psychophysical experiments were conducted using the Delboeuf illusion paradigm.
Participants adjusted the diameter of a test circle to match the perceived size of a referent circle under varying stimulus conditions.
The magnitude of the illusion was quantified by the difference in diameters after perceived equality was achieved.

Main Results:

Illusion magnitude varied with stimulus type and contrast; filled circles with luminance contrast produced stronger illusions than open circles or isoluminant colors.
Stimulus luminance variations had minimal impact, but the illusion diminished as luminance approached isoluminance with the background.
A neurophysiological spatial filtering model accurately predicted experimental findings.

Conclusions:

The Delboeuf illusion's strength is significantly influenced by stimulus contrast and configuration, particularly luminance contrast.
Luminance and isoluminance play critical roles in modulating the perceived size, with diminished illusion near isoluminance.
Computational modeling supports the experimental results, offering insights into the underlying neural mechanisms of size perception.

Related Experiment Videos