Pinna-Brelstaff Illusion

The Pinna-Brelstaff Illusion is a visual illusion that demonstrates the role of context and the importance of the visual cues provided by the surrounding environment in our perception of an object. It is an adaptation of the original Pinna illusion.

The illusion is created by displaying a pattern of light and dark bars on a computer screen. The pattern appears to rotate, even though it is actually stationary.

pinna-brelstaff illusion
Pinna-Brelstaff Illusion


Table of Contents

How does the Pinna-Brelstaff Illusion work?

The Pinna-Brelstaff illusion is a kinetic illusion that involves the perception of motion in a still image. It was discovered by two researchers, Bruno Pinna and Tim Brelstaff in 2001. The illusion is created by displaying a pattern of light and dark bars on a computer screen. The pattern appears to rotate, even though it is actually stationary.

The illusion is created by the interaction between the light and dark bars, which creates a sense of depth, and the way that the brain processes information about motion. The brain interprets the light and dark bars as if they were three-dimensional objects, and it uses the relative motion of the different parts of the image to perceive motion. The brain is tricked into perceiving rotation because the light and dark bars create the illusion of three-dimensional shapes that are moving relative to each other.

This illusion can be explained by the theory of “perception of relative motion” the brain relies on the relative motion of the parts of an image to perceive motion. The light and dark bars creates the illusion of 3D shapes that are moving relative to each other, this creates the perception of rotation.

Version of the Pinna-Brelstaff Illusion

The following are some alternate versions of the Pinna-Brelstaff Illusion:



pinna-brelstaff illusion



pinna-brelstaff illusion



Illusions like the Pinna-Brelstaff Illusion

Kinetic illusions are visual illusions that involve motion. They work by exploiting the way our visual system processes information about motion. The brain uses a variety of cues, such as the relative motion of different parts of an image, to perceive motion.

Kinetic illusions take advantage of these cues by presenting images in a way that tricks the brain into perceiving motion where there is none, or perceiving motion in a different direction than what is actually happening

Some similar illusions are below:

The Fraser spiral illusion is an optical illusion that is characterized by the appearance of a spiral pattern made up of concentric circles.

The rotating snakes is a peripheral drift illusion that consists of a grid of shapes, with some of them appearing to be rotating or undulating. The illusion is created by the interaction of the shapes with the neural processing of the visual system.

Rotating Snakes Autokinetic effect
A Version of Rotating Snakes


The Moiré pattern illusion: This illusion is created by superimposing two similar patterns on top of each other, such as a grid of lines or circles. The resulting pattern appears to be moving or changing.

Moiré_pattern
From Wikimedia Commons

The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.

Simultaneous Contrast Illusion



The Hermann Grid Illusion in which the intersections of a white grid on a black background appear to be gray, even though they are actually the same color as the background.

Hermann-Grid Illusion


The Zöllner Illusion, in which parallel lines appear to be tilted or bent when intersected by diagonal lines.

Zöllner illusion


The barber pole illusion is an optical illusion that is characterized by the appearance of a spiral pattern on a vertically striped pole.


The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  

Bezold_Effect
from Wikimedia Commons


The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.

Cafe Wall Illusion


Discovery of the Pinna-Brelstaff Illusion

It was discovered by two researchers, Bruno Pinna and Tim Brelstaff in 2001.

Bruno Pinna is an Italian psychologist, known for his research in visual perception and his discovery of the Pinna illusion. He is currently a full professor of psychology at the University of Cagliari, Italy.

Pinna’s research focuses on the study of visual perception, in particular, the way in which the brain processes visual information and how it is influenced by the context of the visual environment. He is best known for his discovery of the Pinna illusion, which demonstrates the role of context and the importance of the visual cues provided by the surrounding environment in our perception of an object.

Pinna has published numerous papers on visual perception and the Pinna illusion in scientific journals, and he is considered a leading expert in the field of visual perception. He is also a member of various scientific societies and has been invited to give lectures and presentations on his research at conferences and universities around the world.

References and Resources

Check out our complete list of illusions.


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